| Subject | Date Asked |
|
| recharageable batteries | 1/5/2009 |
Q: power consumption. I just wanted to know how much electricity is consumed when charging rechargeable ...
A: The cost of power to charge small batteries is very small. For charging a laptop battery with a ...
|
| DC | 12/22/2008 |
Q: I have a lot of battery powered toys and was wondering if one can convert them to run on a dc ...
A: To figure the voltage, multiply the number of cells (i.e. AAA, AA, C, or D) that comprise the ...
|
| Operating electrical tools 50 Hz to 60 Hz | 12/21/2008 |
Q: I had several tools such as bench grinder, cordless drill, circular saw, jig saw, router, all that ...
A: If they are just motor-driven, without electronics, they should run OK with no problem. If they ...
|
| Pioneer SA-9500 diagnose | 12/21/2008 |
Q: I have a vintage pioneer SA-9500 amplifier, after it powers up--circuit can hear click, and I have ...
A: It sounds like there is a circuit breaker (or thermal overload interrupter) that opens up and then ...
|
| Guitar Amp Head/Cabinet Impedance...HELP!!! | 12/11/2008 |
Q: Saw one of your articles online and was impressed, so I figured you'd be a good "go to" guy, ...
A: I'm not familiar with your terminology, but it seems that by "heads", you mean the amplifiers, and ...
|
| Math for electrical engineers | 12/10/2008 |
Q: How much math does an electrical engineer need?
A: Of course, I use algebra every day. I often use trigonometry and geometry. Sometimes I use the ...
|
| alkaline batteries | 12/9/2008 |
Q: are store brand alkaline batteries(i.e.walgreens) just as good as dura cell or energizers? or is it ...
A: It used to be the case that Dura Cell was significantly better than the others, as evidenced by ...
|
| Ceiling fan wiring | 12/5/2008 |
Q: I am wiring a ceiling an with light to the electrical box on the ceiling, but there is no earth wire ...
A: The earth wire (ground wire) is supposed to be connected so that you won't get a shock if you touch ...
|
| servomotor | 12/2/2008 |
Q: I need to know the difference between servomotor and normal motor.
A: I assume that you have an idea of the definition of a "normal motor". A servomotor includes a ...
|
| capacitors, circuit stability | 11/19/2008 |
Q: how do i decide on the capacitors required for filtering noise in an electronic circuit? i have ...
A: Your questions are somewhat general, and I'd need more info on what you're trying to do in order to ...
|
| opamps, relays, pumps | 11/18/2008 |
Q: OPAMPS: opamps have high input impedance and so take very less current at their input pins. then ...
A: In a voltage follower, I would not put a resistor in series with the op amp input (non-inverting ...
|
| LVDT Modelling | 10/31/2008 |
Q: Ok, I have a really challenging one for you: I have an LVDT that I need to run at a pretty high ...
A: Almost all LVDTs will work fine with an excitation frequency of 6 kHz. To test, connect a variable ...
|
| LVDT Modelling | 10/30/2008 |
Q: Ok, I have a really challenging one for you: I have an LVDT that I need to run at a pretty high ...
A: I'd have to see the spec you're looking at to be sure. Most specs for an AC LVDT don't list the ...
|
| LVDT Modelling | 10/30/2008 |
Q: Ok, I have a really challenging one for you: I have an LVDT that I need to run at a pretty high ...
A: 600 Hz is a fairly low frequency for the excitation of an LVDT. The most common frequency used on ...
|
| how to Sense tile stepping? | 10/27/2008 |
Q: i'm doing a project for spastic children in which i'm required to detect the stepping of a child on ...
A: A good way would be to bond a strain gage sensor (such as a metal foil type) to the bottom of the ...
|
| how to prevent probes' corrosion? | 10/27/2008 |
Q: i'm an electronics student. i was building a water lvl controller(based on water conduction). i'm ...
A: It would be better to coat the electrodes with a non-conductive protective coating and to measure ...
|
| Bug Zapper Transformer | 10/26/2008 |
Q: Hey Dave, I've got an old Bug Zapper laying around and i was wondering if it was possible to take ...
A: The transformer itself will not generate a continuous high voltage when only it is connected to a 9 ...
|
| ac to dc power conversion | 9/22/2008 |
Q: Actually I'm responding / questioning an answer from Cleggsan but he is not accepting new ...
A: The calculation is correct if the right numbers are used. Unfortunately, most equipment and ...
|
| Operating an AC relay on DC | 8/4/2008 |
Q: I have a 120 VAC relay operating on 48 VDC. The relay operates fine and the coil isn't as warm as ...
A: That is possible, and depends on the magnetic hardness of the core material. You can't be sure ...
|
| 4-20 mA signal conditioning | 8/1/2008 |
Q: I have a level sensor factory scaled for 0-10 psi. I actually need a range of 5-6 psi. Is there a ...
A: The closest thing I know of is the Transpak by Action Instruments. It has up to 80% turndown, which ...
|
| Fuses | 7/10/2008 |
Q: Is it correct general purpose fuses are used to protect against overcurrent faults and thyristor ...
A: Both types will open up in the event of an overcurrent, which also occurs with a short circuit. But ...
|
| rtd interfacing | 7/1/2008 |
Q: sir i need to interface an RTD with the 8086 microprocessor. this is a part of my project at a ...
A: 1. You can buy an RTD signal conditioner with a digital output type that you'd like to use. They ...
|
| Half Wave Voltage Multilier Problem | 6/13/2008 |
Q: I hope you can help me with this problem. I have one of those Tennis Racket electronic bug zappers ...
A: If you have 1500V, it looks like the diode rated voltage is too low, at 1000V. You need to change ...
|
| Battery and UPS | 6/11/2008 |
Q: I am going to purchase UPS of 3KVA. Company is offering a UPS with 120 AH. what is the advantage of ...
A: 3kVA (3000 volt-amps) means that it can power a load of 3 kW (3000 kilowatts) if it is a resistive ...
|
| Trying to save the environment.. | 6/4/2008 |
Q: I have an old NEC battery charger, which list its output as: Vcc: 13.0V- 0A/1.7/2.8A VCV: 13.0V - ...
A: Sorry, but that won't quite work. To fully charge a car battery, it has been traditionally agreed ...
|
| DC to AC Inverters | 5/21/2008 |
Q: How concerned should I be that a modified sine wave inverter, converting 12v DC to 120V AC, will ...
A: I don't think there would be any problem with a radio, CD player, TV or stereo, since they convert ...
|
| Charging my laptop with 110V and 400 HZ | 5/14/2008 |
Q: I fly very often and some pilots friendly allow me to recharge my laptop batteries using the ...
A: Your charger should have a listing of the acceptable voltage range and frequency range. Mine says ...
|
| Voltage regulation | 4/22/2008 |
Q: My original idea was to use the stator and regulator from an old motorcycle, but 1/8" not enough ...
A: The cooler probably takes at least 40W, so your load would total at about 100W. If it is providing ...
|
| Current limiting - expansion on previous | 4/10/2008 |
Q: I have (as a hobby) built an electrolysis cell for my car that splits water into H2 and O2, and ...
A: The simplest way would be to make a 5A current limiter using an LM338, and then use 4 of them in ...
|
| electricial wiring | 4/5/2008 |
Q: can you explain to me how a relay works and explain a dry contact and it's purpose
A: A relay has two main functions: an electromagnet, and a switch. An electromagnet is a coil of wire ...
|
| electrical | 3/25/2008 |
Q: what are the advantages and disadvantages of 220v,50hz in india and 110v, 60hz in usa.
A: The 50 or 60 Hz makes very little difference. 60 Hz has a slight advantage in product design, ...
|
| help.. | 3/24/2008 |
Q: my question.how to Convert 5vDC To 12vDC.?
A: To convert 5VDC to 12VDC, you would use a switching regulator circuit. There are integrated ...
|
| EET | 3/23/2008 |
Q: 1)why do cells connect in parallel 2)what is a shunt resistor
A: I'm not sure that I understand your question, but here goes: the cells of a battery are normally ...
|
| dry contact water sensors | 3/21/2008 |
Q: I'm looking into getting a Sensaphone system with water sensors to help me ensure that my basement ...
A: From your description, there are water sensors that have dry contact outputs, and those connect to ...
|
| Great invention | 3/9/2008 |
Q: Dave how do you have an electronic invention assessed with out it being stolen?
A: You can do it yourslf, or you can hire a patent attorney. A patent attorney is legally bound to ...
|
| Charging batteries | 3/4/2008 |
Q: I have an invertor installed at my home incase of power failures. It employs a 12v 150Ah battery. I ...
A: It would be a lot of work to build one, with a transformer, rectifier, filter, voltage regulator, ...
|
| electrical problem | 2/29/2008 |
Q: why is it that electrical power is transmitted at high voltage?
A: Power is transmitted at high voltage in order to reduce loss over the transmission wires. At a ...
|
| Voltage between two GNDs of two independent SMPS? | 2/28/2008 |
Q: I have just lost the firewire port of my camcorder to bad luck... I wanted to verify the tale of a ...
A: That's theoretically possible, but would require that both camcorder and computer be referenced to ...
|
| pic light chaser | 2/26/2008 |
Q: i'm trying to build a pic light chaser using pic16f84 with 16 leds. can you tell me which pins to ...
A: There may not be enough pins to run each LED on a separate PIC pin. Anyway, light chasers usually ...
|
| 9v dc to 1.5v dc for led | 2/22/2008 |
Q: I am in the process of altering an EMF meter. I have already installed a switch allowing me to cut ...
A: It depends on how much current is needed to make the LED provide the amount of light that you need. ...
|
| Smallest Battery for LED | 2/7/2008 |
Q: Sorry apart from plugs and speaker wire I am completely new to electroncs. My plan is for a ...
A: You can use a small battery if you use an efficient red LED that provides a good amount of light ...
|
| AC relay's contacts in DC circuit | 2/6/2008 |
Q: Can the normally open/closed contacts of a relay, which is being energized by an AC ciruit, be wired ...
A: The contacts will work with DC, but the voltage and current ratings will each be about five times ...
|
| Interview Questions | 2/5/2008 |
Q: 1. What is the starting salary for someone in the electrical engineering field? 2. What is your ...
A: I started my own company 5 years ago (www.rev.bz), and so I work mostly by myself, but 5 or 6 ...
|
| Current boost circuit | 2/3/2008 |
Q: I have a circuit that has a light-duty battery - 3V, 240mAH. The circuit is in 'sleep' mode, ...
A: Maybe you glossed over my answer too quickly: I did not say 0.47 uF, I said 0.47 F (0.47 Farads, ...
|
| Current boost circuit | 2/2/2008 |
Q: I have a circuit that has a light-duty battery - 3V, 240mAH. The circuit is in 'sleep' mode, ...
A: 240 mAH means that the battery can supply 240 mA for 1 hour. It does not mean that the current is ...
|
| Line regulation | 1/28/2008 |
Q: A circuit requires 3v at 1A. Does it matter if I use a 3v 150 Ah battery as the source? What does a ...
A: It's OK to use the 150 Ah battery: it means that it can supply 1A for about 150 hours. Normal ...
|
| Lamp Dimming using a resistor? | 1/27/2008 |
Q: I would like to thank you in advance for any advice you can offer on my question. I live in UK and ...
A: Sorry, but simply adding a series component is not really practical for several reasons: if you ...
|
| Rating | 1/19/2008 |
Q: I got an unknown capacitor with " E 222k 2kv" printed on top of it. What does this mean and what ...
A: The many capacitor manufacturers don't use all of the same codes, but this should be it: Of ...
|
| 60 to 50 hz | 1/17/2008 |
Q: I read the answer regarding various appliances and equipment designed for 60 HZ but running on 50 ...
A: It's difficult to say for sure without knowing what circuit is used inside, if it doesn't state that ...
|
| Dry Contacts | 1/16/2008 |
Q: Dave, I'm an electrical engiener who recently began working in industrial automation, we use dry ...
A: I'm not sure that I understand your question. A set of dry contacts is the same as a SPST switch. ...
|
| Diodes | 12/29/2007 |
Q: In a circuit that carries about 5kv, can we use 1N 4007 diodes ? In 4007 diodes have a PIV of 1000v ...
A: to place them in series is very tricky. they each have different characteristics and don't share ...
|
| Voltage | 12/28/2007 |
Q: In a series voltage multiplier of n stages , do all the n capacitors have the same voltage rating? ...
A: The voltage across each capacitor becomes greater with each successive stage, and so the caps need a ...
|
| LF Timer Circuit | 12/20/2007 |
Q: I'm trying to design a circuit that produces a short pulse every minute or so. Problem is, the ideal ...
A: The simplest way is to use a CMOS dual one-shot ic, like an LTC556. It only takes about 100 uA at ...
|
| LF timer | 12/20/2007 |
Q: I'm trying to design a circuit that produces a short pulse every minute or so. Problem is, the ideal ...
A: The simplest way is to use a CMOS dual one-shot ic, like an LTC556. It only takes about 100 uA at ...
|
| ELECTRIC | 12/11/2007 |
Q: I'M SPANISH ELECTRONIC INDUSTRIAL UNIVERSITY STUDENT, I'VE NEVER GOT CLEAR WHY SOMETIMES WE TALK ...
A: I don't know what you mean by a "Font". If you use water as an analogy, voltage is like the water ...
|
| ELECTRIC | 12/11/2007 |
Q: I'M SPANISH ELECTRONIC INDUSTRIAL UNIVERSITY STUDENT, I'VE NEVER GOT CLEAR WHY SOMETIMES WE TALK ...
A: It is incorrect to refer to "voltage consumption". Voltage is the potential difference across two ...
|
| DC generator | 12/10/2007 |
Q: I am making a mini DC generator and it needs to be variable wattage, approximately 20 watts with a ...
A: You will probably run it at a constant speed to keep the ripple low, and you will probably run a ...
|
| Battery Preservation | 12/10/2007 |
Q: Since one usually has to buy batteries at a store in packs, how can I store the batteries I don't ...
A: I used to keep batteries in the refrigerator years ago (without a plastic bag). But now, the ...
|
| Temperature Sensor Interface | 11/13/2007 |
Q: I want to build a temperature sensor to input into my pc, and use that input to change the speed of ...
A: Several companies sell temp sensors that connect via USB, like the one on this webpage: ...
|
| Electrical | 11/11/2007 |
Q: How to do meggering? what are the procedures?
A: "megging" is done by using a megohm-meter (also called a megger), in order to test insulation ...
|
| generator breaker size | 11/7/2007 |
Q: If i have a 250KW diesel generator at 230volts 3 phase. What size circuit breaker should be ...
A: If you take the 250 kW and divide it by 230 volts, then divide it by the 3 phases, you get 362 amps ...
|
| Surround Sound Speakers | 10/15/2007 |
Q: The previous owners left Bose surround sound speakers and I plan to hook them up to my Sony ...
A: As long as you connect both speaker cables in the same way, it doesn't matter. If they are not the ...
|
| residential wiring | 10/10/2007 |
Q: Let's say we have a simple AC residential circuit with a black "hot" wire, white "neutral" wire and ...
A: The neutral wire is always at or near ground potential, so that's why it's not called the "hot" ...
|
| residential wiring | 10/9/2007 |
Q: Let's say we have a simple AC residential circuit with a black "hot" wire, white "neutral" wire and ...
A: The neutral wire is connected to ground at some point in the local wiring system. (e.g. it is ...
|
| low voltage dc | 9/18/2007 |
Q: I need to reduce the dc voltage on a remote control helicopter/gyro from approx 1.2v to .6v. There ...
A: If you add a series resistor, then you'd first need to know the current draw from the gyro. But the ...
|
| About volage droop in Alternators | 9/18/2007 |
Q: What is the function or tell me about the happening of voltage droop in Alternators.
A: The best way to explain this is to send you to this webpage: ...
|
| power suply | 9/17/2007 |
Q: I bought a 15 inch flat screen tv which is powered by transforming 240v to 12 volt. Would I be able ...
A: I don't know what you mean by "leisure battery", but does the "240v to 12v transforming" mean that ...
|
| relay | 9/17/2007 |
Q: i am currently designing a moisture sensor circuit.the circuit uses a 9V BATTERY as a supply ...
A: The 741 can only supply a few mA, and probably can't power the relay coil directly. You can connect ...
|
| CT meter | 9/7/2007 |
Q: Please explain the different between CT meter and direct meter for the electrical supply from the ...
A: The electromechanical induction meter (which I think you are calling a direct meter) operates by ...
|
| project name | 9/4/2007 |
Q: I am final year student of B.E(electronics).Now i am making my final year project.My question is ...
A: What you have sounds OK. As another possibility, how about MIDAS (like the King for whom ...
|
| AC Relay Signal to DC Dry Contact | 9/3/2007 |
Q: I'm working on a bit of a home project. What' I'm looking to do is connect my Firex alarm system to ...
A: The card is looking for a set of dry contacts, which means that it needs to have its two terminals ...
|
| Sensors, Circuits | 9/2/2007 |
Q: I'm an electrician and my job ends at the receptacle so to speak. Would you, in a nutshell, explain ...
A: That's a very broad subject, so I'll limit my response to your example of a temperature sensor. A ...
|
| power adaptors - digital devices | 9/1/2007 |
Q: 1) If a device such as a print server, 10/100 switch, external drive, etc. has an input power ...
A: 1. The voltage rating must be the same. The current rating can be the same or anything greater than ...
|
| 60Hz Device on a 50 Hz supply | 8/23/2007 |
Q: I just bought a subwoofer from US that runs on 111V 60 Hz. I live in india where the supply is 220V ...
A: If you match the voltage correctly, it should be ok. The difference between the 50 and 60Hz will be ...
|
| Electrical(9v wire connection to AAA connection)? | 8/20/2007 |
Q: how can i change a 9v connection(device uses 9V batter ), to a Tripple A connection( I want to be ...
A: No. The radio needs 9 volts, but one triple A cell has only 1.5 volts. You would need to follow my ...
|
| Electrical(9v wire connection to AAA connection)? | 8/20/2007 |
Q: how can i change a 9v connection(device uses 9V batter ), to a Tripple A connection( I want to be ...
A: I'm afraid that this will be fairly complicated. You'll need to use a switching regulator circuit ...
|
| want a simple circuit.. | 8/16/2007 |
Q: "I want a simple circuit to control one lamp from three independent two way switches"
A: Since there is not an easy way to draw a schematic on this website, the best way for me to answer ...
|
| Parallel Termination question | 8/15/2007 |
Q: On a PCB tranmission line trace, one of the popular way to terminate the signal is to place a ...
A: Actually, it doesn't quite work that way because the transmission line comprises inductance and ...
|
| LM3914 used with 0-1V voltage input signal | 7/30/2007 |
Q: I have PCB kit from Jaycar I'm trying to modify to do what I want. All the LEDs are on a common rail ...
A: Please look at the data sheet at http://www.national.com/ds/LM/LM3914.pdf The outputs of the ...
|
| Valve Positioner | 6/14/2007 |
Q: Goodday. Would like to ask the operation behind valve positioner and I/P converter. Hoe do these ...
A: A valve positioner is a device that is connected to a valve to drive the valve to the desired ...
|
| Adapter voltage question | 6/12/2007 |
Q: I'm looking for some advice about power adapters. I have an old sequencer that I acquired without ...
A: Most likely, 12V would not damage it, but you can't say for sure without knowing the internal ...
|
| Power Adapter vs Charger | 5/26/2007 |
Q: First of all I hope you have a good day. I've lost my Ni-Cd battery charger, could I use AC-DC power ...
A: It took me a little longer to respond because I couldn't get the website to work. In order to ...
|
| Power Adapter vs Charger | 5/26/2007 |
Q: First of all I hope you have a good day. I've lost my Ni-Cd battery charger, could I use AC-DC power ...
A: adapters are not specified well so you will also need a meter. you need a voltage about 1 to 3 v ...
|
| Internal Resistance | 5/15/2007 |
Q: backstory: we were setting up a bouncy-castle in a field (which uses a big fan), and a long ...
A: A permanent magnet DC motor with standard brush commutation can be controlled somewhat by varying ...
|
| notebook computer car adapter | 5/4/2007 |
Q: Yesterday we received a new HP notebook computer from a dealer because they could not fix the ...
A: Sorry to say that in order to completely answer your question corrctly, I'd have to see the ...
|
| modeling a LVDT | 5/3/2007 |
Q: need some advice: Have to model a LDVT using a transfer function. Some data sheets provided a ...
A: No LVDT manufacturer specifies the frequency response of an AC:AC LVDT. That's because the ...
|
| modeling a LVDT | 5/2/2007 |
Q: need some advice: Have to model a LDVT using a transfer function. Some data sheets provided a ...
A: I'm not sure that I know what your question is. An LVDT (linear variable differential transformer) ...
|
| motors, electronics, transients. | 5/1/2007 |
Q: I'm installing a wireless RTD transmitter next to a 5hp moter on a movable structure. I'm using 230 ...
A: Sorry to say that this is an area where good information is difficult to find. Most sources would ...
|
| Rice cooker | 4/18/2007 |
Q: How does a rice cooker knows when to off the cooker?(how the cooker knows the rice has been cooked?) ...
A: You put in a measured amount of water, and the amount of water determines how long it will steam. ...
|
| Jump start | 4/18/2007 |
Q: When we want to jump start battery, why is the sequence are 1.connect + lead to dead battery ...
A: For a lead-acid battery as in a car, it is better to use constant current charging (I). The voltage ...
|
| Jump start | 4/17/2007 |
Q: When we want to jump start battery, why is the sequence are 1.connect + lead to dead battery ...
A: The car body is connected to the battery negative (called negative ground). If you connect the - ...
|
| Battery Ah | 4/17/2007 |
Q: I still can not capture the meaning of battery Ah. Could you explain.
A: If a battery has a rating of 1 Ah, then it theoretically can supply a current of 1A for a time of 1 ...
|
| reducing voltage | 4/16/2007 |
Q: First of all I don't know very much about electronics. So anyway , I built a lighthouse to sit in ...
A: Yes, but it would be a lot to explain in this forum. If it's DC, you can add a voltage regulator. ...
|
| Speaker | 4/14/2007 |
Q: I was thinking of buying the following amplifier: ...
A: You can use 6 ohm speakers if they meet at least the power rating of the amp. The power you get may ...
|
| selsyn/synchro transmitter | 4/12/2007 |
Q: Goodday, Could you brief about this or maybe recommend some website. I browse through websaites, but ...
A: If you are only measuring a shaft angle, then you use a synchro. The synchro shaft is mechanically ...
|
| selsyn/synchro transmitter | 4/12/2007 |
Q: Goodday, Could you brief about this or maybe recommend some website. I browse through websaites, but ...
A: First read this: http://en.wikipedia.org/wiki/Selsyn So, as you turn the shaft on the synchro, you ...
|
| Gyro | 4/7/2007 |
Q: What is Integarting Gyro and Rate Gyro?
A: A rate gyro indicates the rate of turn, with an output indicating angular degrees per second. A ...
|
| Meanings of Dry Contact | 4/5/2007 |
Q: I always heard about 'dry contact'. What is meant by this?
A: A dry contact is a set of 2 switch contacts, like a set of contacts from a relay or from a toggle ...
|
| Battery Charging Condition | 4/2/2007 |
Q: Goodday Here we have a charger which charges 2 banks of battery. The system is operating where for ...
A: It depends on the battery and on the charger circuit. If the battery is the type that has a memory, ...
|
| FPGA | 4/2/2007 |
Q: sir, i have been in to digital design for last 8 years. i had started with discrete component ...
A: A field programmable gate array contains a large set of logic elements that are interconnected by ...
|
| AC and DC Capacitor | 4/1/2007 |
Q: Goodday.. For UPS inverter or rectifier, there are AC and DC capacitor. From what I know, capacitor ...
A: There is no such distinction as between an AC or DC capacitor. If you rectify an AC, the voltage ...
|
| Current Loop Explaination | 3/31/2007 |
Q: Goodday.. For a 4-20mA loop we have 4 major components those are the sensor/transducer, ...
A: There are a lot of possibilties. Are you installing a new system, or trying to understand what is ...
|
| Battery Charging Amps | 3/31/2007 |
Q: I was told there is rule of thumbfor battery charging amps. For Nicad is 25%xAh and SLA/VRLA is ...
A: That is true and correct for many cases, but you have to check the specific cells that you are using ...
|
| Current Loop Explaination | 3/31/2007 |
Q: Goodday.. For a 4-20mA loop we have 4 major components those are the sensor/transducer, ...
A: Normally, only one device would be used to measure the temperature and generate the 4 to 20 mA ...
|
| 4-20mA signal | 3/28/2007 |
Q: I still dont understand the concept of this 4-20mA signal. Could you give some example of system. I ...
A: I'll use an example of a temperature sensor that has a range of 20 degrees to 120 degrees. When you ...
|
| CT meter | 3/24/2007 |
Q: I'm trustee for a Baptist Association building. The city utilities are charging us a demand rate ...
A: To get the current in each phase on a 3 phase 208VAC line when the power dissipation is 66kW and ...
|
| CT meter | 3/24/2007 |
Q: I'm trustee for a Baptist Association building. The city utilities are charging us a demand rate ...
A: Yes, it does not seem fair because you are paying more for a given amount of energy. Yes, the meter ...
|
| CPT | 3/23/2007 |
Q: do you ever heard about CPT -Current Position Tansmitter. Could youexplain how it works and for what ...
A: I haven't heard of that term before, so I looked it up on the web. The term CPT is specific to a ...
|
| installing an under the cabinet lumiere | 3/6/2007 |
Q: I am installing an under the cabinet light. I have to install teh on/ff switch to the outlet plug. I ...
A: Their description is talking about the plastic insulation on the wires, along the part of the cord ...
|
| battery packs | 3/1/2007 |
Q: So, let me get this straight. I can go with higher amps, much higher without causing damage to my ...
A: Yes, that's right. You have to have the voltage right so that the device will work properly. But ...
|
| battery charging system | 2/28/2007 |
Q: That was my assumption too, I even thought go with #10 or even #6 to be safe at that distance , But ...
A: I'm assuming that 30A is the max charge rate, but the normal rate should be something like 3A. 12 ...
|
| battery packs | 2/28/2007 |
Q: first i want to thank you for sending me a reply, I found it very usefull. But I still have one ...
A: A 12V car battery would provide power for a longer time than the D cells. I picked the D cells ...
|
| battery charging system | 2/28/2007 |
Q: we have a battery charging system we want to install It's input is 120 volts,14.5 amp to run. ...
A: If you are running 30A for up to 150 feet, you should use 12ga wire for each run. That gauge will ...
|
| One last thing | 2/21/2007 |
Q: Okay, one last question. I'm only asking you because you've given me the most straightforward ...
A: It seems that you might have the diode connected in backwards, because the ammeter reading should be ...
|
| electric baseboard heating | 2/19/2007 |
Q: I have an electric baseboard heater built in to the wall (that needs to be replaced) that is 120 ...
A: No, not easily. In order to use the 240 volt heater, you'll need to run another wire from the power ...
|
| miliampers | 2/18/2007 |
Q: i want to buy a high power led rgb 700 miliampers. but i was told that miliampers is not miliamps. ...
A: It seems that you were told wrong. Milliampere means one thousandth of an ampere. An ampere is a ...
|
| bicycle generator | 2/18/2007 |
Q: me again. I now have 2 options. I actually got a 1000v diode with a 1amp rating. I know that it ...
A: I don't remember what your question was, but I think you were trying to charge a battery by ...
|
| c.t | 2/17/2007 |
Q: What is the purpose of calculating knee point voltage for Current transformers?
A: A current transformer is an instrument transformer in which the secondary current is substantially ...
|
| Mains Tester | 1/28/2007 |
Q: Having bought a mains tester (a screwdriver that has a neon that lights up when you touch the hot ...
A: The neon lamp takes so very little amount of current to light, that only the capacitance from the ...
|
| Bicycle Generator | 1/27/2007 |
Q: I recently put together a bicycle generator. I used a 12v fan motor for my generator. I can power a ...
A: When you pedal the generator, one of the two leads is the positive one. You can check which one by ...
|
| RTD | 1/25/2007 |
Q: Goodday Dave I have questions regarding RTD. I guess we can consider it as a sensor. First of all, ...
A: I'm not sure that I understand all of your question, but I think this will provide the answers you ...
|
| Electric tools | 1/24/2007 |
Q: Is there a tool available for measuring amps used by a lamp or appliance? What is it called? I ...
A: It's called a clamp-on multimeter. You can get one for $99 at Northern Tool: ...
|
| Thermocouple Test | 1/21/2007 |
Q: A few days back, i saw an instrument engineer use a meter to check a thermocouple. I was told the ...
A: 1. A complete thermocouple connection includes two junctions: one is the measuring junction, and ...
|
| Correct power supply required for home project? | 1/18/2007 |
Q: One follow up question though regarding your statment "AT LEAST 2amp". If were unable to locate ...
A: As long as the voltage rating of the power supply is correct, it doesn't matter if the current ...
|
| Correct power supply required for home project? | 1/18/2007 |
Q: I've connected four small (identical) fans together in parallel (the type used in computer power ...
A: When you first turn on a DC motor, it has a much larger current to get started. After it's up to ...
|
| Positioner | 1/17/2007 |
Q: I came across this word several times. But I dont actually unserstand what it is and how does it ...
A: It is a general term used in motion controls. In a motion control system, you generally have a ...
|
| Sensor/transmitter 4-20mA | 1/15/2007 |
Q: Meaning to say from from power supply there will be a +ve and -ve terminal that goes to the ...
A: Yes, the power supply would be a constant 24VDC and capable of supplying more than 20mA. You can ...
|
| Sensor/transmitter 4-20mA | 1/15/2007 |
Q: Could you explain a bit about the sensor using 4-20mA signal? How does it relate (sensor/transmitter ...
A: I'll explain a temperature sensor as an example to get started. If you have a 4 to 20 mA temperature ...
|
| Reverse current | 1/8/2007 |
Q: I really need a formula to calculate that current. I need to calculate that protection diode to use ...
A: The exact current only needs to be calculated for the purposes of an electronics math class. In ...
|
| Reverse current | 1/8/2007 |
Q: I have a circuit with a battery (Vvolts), an inductor with a diode in parallel and a key When ...
A: Short explanation: When current is passing through the inductor with the key closed, the coil ...
|
| IGBT/MOSFET Converter (DC-DC) | 1/3/2007 |
Q: I noticed in most dc-dc converter, they use flyback converter ( correct me if i wrong ). There ...
A: There are many configurations of Dc-Dc converters. They store a charge in an inductor or capacitor. ...
|
| Gas Turbine Generator | 12/24/2006 |
Q: 1.In the protection system of generator, there is under/over frequency relay. How does this relay ...
A: 1. There are several ways. One way is to use a counter that counts the frequency signal for a fixed ...
|
| differential signal | 12/23/2006 |
Q: I see in some documents people say that we can transmit differential signal.But I do not understand ...
A: A typical single ended signal could be with two wires, where one has a voltage of either 0V or 5V, ...
|
| Meggering | 12/10/2006 |
Q: 1.What is the concept behind meggering a cable and the voltage we inject?Why we inject? 2.Let say ...
A: I would not call it "injecting" a voltage. I would call it "applying" a voltage. With two ...
|
| automotive electrical system | 12/8/2006 |
Q: computers are able to receive and process both analog and digital signals. True or False?The EEPROM ...
A: The actual "computing" part of any modern "computer" only works with digital data. When analog ...
|
| Information Request | 11/29/2006 |
Q: Today we are contacting you in regards to our engineering Design and Development project. We are two ...
A: I assume that your intent is to prevent someone from getting their finger or hand caught in the door ...
|
| Short Circuit Faults | 11/24/2006 |
Q: Would appreciate your assistance to answer the following (in layman terms if possible): - What is ...
A: When a circuit is expected to be connected in a particular way, but instead there is a relatively ...
|
| 208v 3 Phase Power Aggregate Draw Higher Than Predicted | 11/20/2006 |
Q: I have 26 servers each drawing 1.2 amps. They are plugged into a power tower taking one three phase ...
A: This is a little complicated to answer. Three phases with each one having 16 A is not the same as ...
|
| reduce voltage | 11/20/2006 |
Q: I have an outlet in my house that puts out over 240 volts. I'm afraid to plug anything into the ...
A: Don't connect any 110V device to the 220 V line. It will be damaged. Unfortunately, you probably ...
|
| Diode Question | 11/16/2006 |
Q: You say a 30A diode. What voltage rating do I look for?I use one of those portable power packs in ...
A: It should be rated for 60 volts or higher. The reason that it is so much higher than 12 volts is ...
|
| ECM Motors | 11/15/2006 |
Q: I have the endbell of a GE ECM motor for an Amana air handler with a small nickel sized device ...
A: In your rating, you mentioned that you could not ask a follow up question. Unfortunately, there is ...
|
| engineering | 11/15/2006 |
Q: what was it like when you first started working?
A: When I first started working, it was sunny, about 70 degrees, the birds were singing... (just ...
|
| Diode Question | 11/15/2006 |
Q: I use one of those portable power packs in my car to jump the car if the car's battery dies. My ...
A: The cathode of the diode should be toward the battery pack positive lead. The diode should be rated ...
|
| Faraday Cage/Ice pail effect | 11/7/2006 |
Q: If I wrap a radio in thin tin foil so the foil acts as a faraday cage, the electric field of the ...
A: A changing magnetic field induces eddy currents in a conductor, and therefore causes loss of the ...
|
| 220V from China | 10/27/2006 |
Q: I'm not sure if you can help, but I wouldn't be suprised either from your profile! I have a machine ...
A: You might want to get an electrician to help you, since it can be dangerous to install AC wiring. ...
|
| Mouse powered electricity | 10/18/2006 |
Q: How could I make a light bulb light up with a mouse running on it's wheel?
A: I don't know how much you may know about electronics, but here's what I think would be the simplest: ...
|
| Reduce Volts and Amps | 9/28/2006 |
Q: How can I get 2 Volts and 30 Amps out of 12 Volt car battery. Thankx Pete
A: You can use a switching regulator integrated circuit like the one at the webpage ...
|
| series circuit | 9/24/2006 |
Q: why is the current the same in qll series circuits?
A: When you measure a current of 1 ampere, for example, flowing through a section of a conductor, it ...
|
| Flow measurement | 9/13/2006 |
Q: Actually when Temperature changes from day to night about 20c in summer then the pressure drops in ...
A: Again, it depends on the system. It may be whatever is controlling the pressure has a sensitivity to ...
|
| Transformer electrostatic screen | 9/12/2006 |
Q: Some transformers have a sheet of metal around the primary winding which is grounded and acts as a ...
A: The shield is intended to reduce electric fields, but also reduces the magnetic field a little, ...
|
| flow measurement | 9/12/2006 |
Q: I m working on a project of my semester.project is for controlling gas regulating valve(so to ...
A: Yes, it is the universal gas law (a combination of Boyle's laws). P1V1/T1 = P2V2/T2 This means that ...
|
| current to volt | 8/27/2006 |
Q: Followup To Question -Hi i have a problem in designing a circuit that converts a current of range ...
A: If you had exactly 24 volts, then you could use a voltage divider from 24V, and an op amp to buffer ...
|
| 220 to 110 | 8/27/2006 |
Q: I have received a gift a few weeks ago, it is a welding machine, i think this is good, but what is ...
A: I think there is no practical, low cost way to do it. The current taken by the welder varies, it ...
|
| photo sensors | 8/25/2006 |
Q: I am doing som work on a boat and need to use a photo sensor in an area that is usually well lit . ...
A: You're talking about a phototransistor. If a semiconductor is doped with extra electrons as charge ...
|
| electricity generation from low heat source | 8/24/2006 |
Q: I read with interest your answer regarding thermopiles+vg. Do you think it is possible to produce ...
A: In order to generate energy with a thermopile (such as a set of thermocouples with a "hot"-side ...
|
| current to volt | 8/15/2006 |
Q: Followup To Question - Hi i have a problem in designing a circuit that converts a current of range ...
A: If you only have a 24V supply, then you can't use the series reference IC that I suggested. ...
|
| filter in PLL | 8/10/2006 |
Q: In PLL, we use a lowpassfilter, but its name is 'loop filter', people don't call it lowpass filter. ...
A: It's just a low pass filter that is tuned for the frequency that's needed for the loop, but it's ...
|
| current to volt | 8/9/2006 |
Q: actually i have an idea of a resistor of 250 ohms, this will lead to have 5 volts when the current ...
A: You can use a 1.25V reference IC, such as a Texas Instruments REF2912 (available from Digikey.com), ...
|
| current to volt | 8/8/2006 |
Q: actually i have an idea of a resistor of 250 ohms, this will lead to have 5 volts when the current ...
A: It would be easier to use a resistance of 312.5 ohms. Then the voltage would be 1.25 to 6.25 volts, ...
|
| AC motor direction | 7/23/2006 |
Q: How do you determine the direction of a commutator motor (serial wound motor) running on AC current? ...
A: It can be very difficult to tell the direction by looking at the motor when it is not powered. In ...
|
| Finding a UPS for an LCD projector! | 7/15/2006 |
Q: i hav recently purchased a SONY(VPL-EX3)LCD projector. It's power comsumption is 220Watts when ...
A: Yes, a 600 VA supply would be fine, if it is rated for 240V input power. The VA rating is ...
|
| Polarity & GFCI | 7/10/2006 |
Q: Your answer was very helpful. Yet, I do not understand the part about the neutral and ground being ...
A: When an electrician wires the power box, he connects the neutral line to a ground. The ground is ...
|
| Volts vs. Watts | 7/7/2006 |
Q: I need to replace an adapter for my stepdaughter's notebook. Her old adapter (her dog chewed the ...
A: Wattage is the amount of power used. It is the voltage multiplied by the current (in amps). You ...
|
| Polarity & GFCI | 7/6/2006 |
Q: What is electric polarity ? How can it cause electrocution? What is crossing wires(i.e. crossing ...
A: Polarity: Electrical current is the flow of electrons. An electron has a negative charge. In an ...
|
| PLL block | 7/4/2006 |
Q: In basic PLL block there is an amplifier (after the low pass filter), but I don't known Why we need ...
A: Not all PLL diagrams show an amplifier. It is not really a functional block, but is shown because it ...
|
| filter | 7/1/2006 |
Q: In some filter circuits, there are an amplifier circuit. I do not why we need an amplifier after ...
A: You can use a passive R/C or L/C filter without an op amp, but its performance will change if the ...
|
| Heating Element in Electric Water Heater | 6/14/2006 |
Q: If I put a fork in a toaster, the fork will conduct electricity into my body. Water is also a great ...
A: The water heater elements have a thick insulating jacket over the electrical resistance wire through ...
|
| cmos technology | 6/13/2006 |
Q: I see many people say '0.5 um technology, 0.18um technology ...'I don't understand What it mean. Do ...
A: When designing an integrated circuit, you are placing a pattern on the substrate so that ...
|
| signal conditioning | 6/12/2006 |
Q: sir, I am astudent of industrial electronics engineering.We are making our project in which we ...
A: 1. the lvdt is driven by an oscillator. the oscillator for that ic can be set from 20Hz to 20kHz. ...
|
| mosfet parameter | 6/12/2006 |
Q: I see there are many mosfet level (level 1, level 2, level Bsim ...).Each level has many parameters. ...
A: I answered this question yesterday, but it looks like it didn't send. So, here it is again: Yes, ...
|
| transistor with inductive load | 5/30/2006 |
Q: I am not a electronic student but I like it very much. So I learn it by myself. And I have a problem ...
A: Yes the equivalent circuit for driving a relay is an inductor. When powered, the inductor has a ...
|
| electricity | 5/24/2006 |
Q: why do you NOT need 3 wires for 220 volts and you need 2 for 120v or do you need 3 wires for 220v's
A: I assume that you're asking about the wiring in a house in the USA. There are two phases of 110VAC ...
|
| digital disply | 5/19/2006 |
Q: I have 0Vdc to 5Vdc analog signal.I want to see it on 7-segment desply in such away that when input ...
A: The simplest way would be to buy a digital panel meter. You can get one from digikey.com for less ...
|
| Inductor time constant L/R | 5/17/2006 |
Q: I can see that a low resistance would allow enough current to flow so the inductor would generate a ...
A: In order to fully discharge a charged inductor, it does not discharge a fixed amount of current. ...
|
| converting amps | 5/13/2006 |
Q: I Want To Run An Air Compressor In My Van It Is Two Horse Five Gallon And Draws 14.5 Amps ...
A: I'm sorry to say that it would not be practical to design and build a "power inverter" (as that type ...
|
| 12v dc to 120 v ac | 5/2/2006 |
Q: Electrical Engineer Questions What is the best way to figure out this question? If I have a 12v dc ...
A: Different types of AC motors (shaded pole, AC/DC, capacitor start, etc.) have different amounts of ...
|
| Inductor time constant L/R | 4/18/2006 |
Q: It is obvious why a capacitor discharges slower with a larger resistance but exactly why does an ...
A: With a low resistance, the inductor discharge current generates a back EMF to limit that current, ...
|
| Piezo Transducer to light an LED | 4/6/2006 |
Q: Nyce. I am working on an idea I came up with, but I am very new to electronics, and it seems like I ...
A: First, it would be good to know if the piezo was able to put out enough energy to run all of those ...
|
| 7-segment | 4/3/2006 |
Q: I want to know how can a point be moved on 7-segment display when using 7447 decoder. For ...
A: The 7447 does not drive the decimal point. You use a transistor and series resistor for each ...
|
| Induction | 3/13/2006 |
Q: The "howthingswork" site decribes the way a transformer works by talking about the electric field, ...
A: As I mentioned earlier, we are talking about the same thing in different ways. And to me, it doesn't ...
|
| Induction | 3/11/2006 |
Q: We know that a changing magnetic field generates a changing electric field... Now, if you take a ...
A: It sounds like you are talking about the same thing in different ways. A changing magnetic field ...
|
| Electrical Appliances Conversion | 3/7/2006 |
Q: I am aware of the voltage differences between the USA and UK. I am perplexed by what do do with a ...
A: Bad news: Simple devices can be operated with an inexpensive converter from Radio shack that ...
|
| Ground on PCB | 3/3/2006 |
Q: on a printed circuit board is it true that generally the ground rail runs round the outer edge of ...
A: It is common for 1 sided and 2 sided PCBs to have a ground rail around the edge because there are ...
|
| LEDs | 2/22/2006 |
Q: Is it possible to hv a LEDs circuit, where the number of LEDs on are depends on the supply voltage. ...
A: You're in luck! The LM3914 integrated circuit from National Semiconductor does exactly what you ...
|
| sensor info. | 1/30/2006 |
Q: plz. tell me about some sensor which can be used to measure liquid level.I know about some ...
A: If the liquid is a dielectric (electrical non-conductor) you can use two metal plates that you can ...
|
| Ohm quandry... | 1/30/2006 |
Q: Dave, I am hoping you can help me! I have a stereo power amplifier that is rated at 200 watts at 4 ...
A: You can operate your 8 ohm speakers with that amp with no problem. The only consideration is that ...
|
| op amps | 1/30/2006 |
Q: In a op amp, if both inputs are grounded, what would cause a voltage to be present at the output?
A: You should not ground both inputs of an op amp. If both inputs are grounded, the op amp still has ...
|
| electronic circuits/electronic theory | 1/29/2006 |
Q: what i think i know: speakers are powered by ac electricity, the frequency of which directly causes ...
A: If you just want to produce a tone at the line frequency of 50 Hz, then you can use a transformer ...
|
| I/v convertor | 1/25/2006 |
Q: I want a circuit for i/v convertor.I know opamp as I/V convertor but it is for low current.I have 0 ...
A: You will need two op amps: one for an inverting I/V (we'll call it the -I/V stage) and one to invert ...
|
| Fuse & switch ratings: amps v watts | 1/21/2006 |
Q: This is probably really basic but... I'm adding a lamp with a 300W bulb to a 24V mobility scooter ...
A: For your fuses and switches, you need to look at the amps, not the wattage. And actually, the ...
|
| LVDT | 1/16/2006 |
Q: I want a circuit for signal conditioning the LVDT.If u can help me then plz. send me a solution.I ...
A: Developing signal conditioning circuits for an LVDT is a part of my business, and involves a lot ...
|
| About relays | 1/8/2006 |
Q: I wanted to make sure one more thing. The relays used in this circuit are all DPDT? because i think ...
A: I thought that you were asking about RL1, because those contacts are shown. I can't say for sure ...
|
| About relays | 1/6/2006 |
Q: visit the following link. http://electronicsworld.tripod.com/remotecontrolsimages/2.gif this is ...
A: The relay shown is DPDT (double pole, double throw). The diode has to be added. The reason for the ...
|
| about a project | 1/2/2006 |
Q: sir, i want to design a electronic circuit.It would be given a ac supply and the amount of current ...
A: There are several books on the subject. Also, application notes are available from the voltage ...
|
| Driving Impedance | 12/18/2005 |
Q: What is meant by the term "driving impedance"? For example, would the driving impedance of an ...
A: I would not use a term such as "driving impedance" without explaining it. I suppose that they are ...
|
| Electromagnetic Currents | 11/20/2005 |
Q: Does electromagnetic current flow faster through a wire if it is thicker? I would think that it ...
A: It looks like you sent this question a few days ago, but I just received it a few minutes ago. I ...
|
| Transistor operation | 11/20/2005 |
Q: My question is about how to think about a transistor in relation to the rest of a circuit.... I'll ...
A: It seems like you are getting a good understanding of how a transistor works, but I avoid comparing ...
|
| Mercury switch replacement | 11/10/2005 |
Q: I'd like to know if there has been any recent development of products to replace the functionality ...
A: Analog Devices Corporation makes an accelerometer integrated circuit. It has a machined silicon ...
|
| Signal DEveloping Resistor | 10/21/2005 |
Q: On the webpage I asked about, a bias resistor is connected to the emitter of the transistor but is ...
A: In the single resistor one, some base current is provided so that the base junction becomes forward ...
|
| Signal DEveloping Resistor | 10/20/2005 |
Q: This webpage: http://www.tpub.com/content/neets/14180/css/14180_68.htm shows R1 being a resistor to ...
A: As shown, the Q1 circuit is not complete. The base needs a resistor to a positive voltage to ...
|
| RC coupling | 10/16/2005 |
Q: In RC coupling between amplifier stages where R1 C1 and R2 are used... why do you need R1 and R2? ...
A: Only the capacitor is needed to couple the AC signal, but the next amplifier stage needs to have its ...
|
| Load Resistor | 10/11/2005 |
Q: When studying power supplies a load resistor is placed in the circuit... is this there in a ...
A: A power supply normally supplies power to a circuit. That circuit is called the load for the power ...
|
| transformer back emf | 10/9/2005 |
Q: A magnetic ballast (inductor) used with a neon lamp produces a voltage spike to start the tube that ...
A: In a switch mode power inverter (also called a boost converter), the output voltage goes up and down ...
|
| 400 hz generator | 10/5/2005 |
Q: I have a 400 hz, 3-phase, 15KW military surplus diesel generator. Can this be converted for use as ...
A: I'm sorry to say that there is really no practical way to convert the alternator. However, you could ...
|
| Dish arial | 10/3/2005 |
Q: Basically, Why can't we use normal aerials (dipoles either hertz or marconi or even a standard Tv ...
A: The signals from satellites are in the microwave range, with periods of only a few centimeters. So, ...
|
| Two guitar amps, one speaker | 9/25/2005 |
Q: Followup To Question - Thanks for your service! I feel like this must be something elementary; ...
A: Now I see the problem. There is no way that the tube amp can drive the speaker if the solid state ...
|
| Two guitar amps, one speaker | 9/25/2005 |
Q: I feel like this must be something elementary; hope so. I set up an arrangement with 1/4" phono ...
A: I read your email several times, and couldn't quite understand your connection (sorry). The main ...
|
| Two guitar amps, one speaker | 9/25/2005 |
Q: I feel like this must be something elementary; hope so. I set up an arrangement with 1/4" phono ...
A: The main amp probably uses a 4 or 8 ohm speaker. The tube amp may need a different impedance ...
|
| Is this power charger ok to use | 9/23/2005 |
Q: I live in Australia and recently bought a Carbon Rio 6GB MP3 Player from the USA which shipped with ...
A: Your understanding is exactly correct. I don't think there is a problem due to the 800 mA rating. ...
|
| Can I splice a power supply and limit voltage? | 8/31/2005 |
Q: I have two devices that need to be powered, and they are different voltages. One is a small 12v ...
A: Yes, you can run the fan from a 12V source, and use a resistor in seires with the Peltier cooler (if ...
|
| simple illumination principle | 8/30/2005 |
Q: does a 40 watt fluorescent lamp give more lumen output than a 20 watt fluorescent having same brand? ...
A: Yes, a 40w fluorescent lamp will have more light output (measured in lumens) than a 20w lamp of the ...
|
| Lamps in Series | 8/23/2005 |
Q: If you have a christmas lamp set which has 20 12V lamps in series running on the mains (UK 240VAC) ...
A: Saying that "current kills, not voltage" is very misleading. It takes something on the order of only ...
|
| Watts | 8/13/2005 |
Q: If I wanted to buy an appliance, let's say a toaster oven and there's one with 1500 watts and ...
A: 1500 watts means that it takes more power than 1200 watts, and generates that much more heat. The ...
|
| Inductor/Ballast and Transformer size | 8/8/2005 |
Q: If you charge up an inductor with a 9V battery until it is magnetized and then remove the battery ...
A: I'm not sure that I fully understand your questions, but: If you suddenly open the circuit after ...
|
| converting light into sound | 8/4/2005 |
Q: can u plz give me an idea on how to convert light frequency into sound frequency? I want to make a ...
A: Radio Shack catalog # 276-5015A is an Engineer's Mini-Notebook. On page 27 is shown the schematic ...
|
| Electric current flow | 8/1/2005 |
Q: If I had a 30cm metal ruler (conductor) with a cm scale on one side and an inches scale down the ...
A: The lowest resistance path on the metal scale would be directly between the electrodes, so some ...
|
| About signal cables | 7/28/2005 |
Q: In many of the books & catalogues they mention signal screened must earth in one end only.that is ...
A: It is often possible that there will be a voltage difference between the "grounds" at each end. If ...
|
| DC Generator excitation | 7/8/2005 |
Q: I have a question about dc generators. On a dc generator, this one in particular is on a engine for ...
A: If a generator is the type that does not use permanent magnets, then it has a field winding to ...
|
| Transformers | 6/26/2005 |
Q: Is a transformer's current rating the amount of current the transformer can deliver SAFELY? I would ...
A: Transformers are rated in various ways. To understand the capability of your particular ...
|
| static electricity | 6/3/2005 |
Q: Is there an electronic device or ciruitry which will produce a "static-electric" charge? (Not a ...
A: Yes. A negative ion generator can be a static electricity generator if you provide a capacitor for ...
|
| Generator Torque | 5/18/2005 |
Q: If you have a 115V generator and connect a lamp to it you will get 115V across the lamp. If you ...
A: The generator provides electrical power to the load, as voltage times amperage. A motor provides ...
|
| Solar panel charger | 5/17/2005 |
Q: How do I go about buying a solar panel that will charge a 6.5 AH, 24v NiMH battery pack? What do I ...
A: A NiMH battery requires a specific charging method, or it can catch fire. I searched on the web ...
|
| Transformer & Turntable | 5/11/2005 |
Q: A transformer is a coil (or 2 coils) of wire round an iron core. Does a transformer have insulation ...
A: The wire for winding a transformer or a speaker coil is coated with a varnish for insulation. ...
|
| HT and Valve without bias... | 5/2/2005 |
Q: If a transformer is HT, it means it has a high internal resistance (many turns) and if you ...
A: Applications requiring high voltage normally don't require much current, so a relatively fine wire ...
|
| Circuit Question | 4/27/2005 |
Q: I was wondering if you had a circuit that would perform a task i have. I need a circuit that will ...
A: What you want is called a monostable multivibrator, or one-shot. You want one that is not ...
|
| Screened cable | 4/25/2005 |
Q: Also, just to check, In the centre of the board there is a big metal can which contains 3 ...
A: The 8uF seems too big for a coupling capacitor, so it could be a power supply filter, as you ...
|
| Vintage resistors | 4/18/2005 |
Q: Going on the assumption that they are resistors (what harm can it do!?) RED, BLACK, RED, BLACK = 2k ...
A: If you can guess approximately what voltage appears across a resistor, you can divide that voltage ...
|
| Vintage resistors | 4/18/2005 |
Q: I am (still) repairing a 1962 HMV record player. In the circuit there are 4 light blue colored ...
A: They sound like resistors. I've seen some that were hollow tubular, with the leads coming off the ...
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| Thevenin's Theorem | 4/9/2005 |
Q: Why Thevenin's Voltage across an element in a circuit containing only single dependent source is ...
A: I guess I don't understand your question. According to Thevenin's theorem, any network of ...
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| Capacitors | 4/5/2005 |
Q: I need to replace 2 capacitors in a 1961 Vacuum Tube amplifier.... One is an electrolytic and it ...
A: Yes, black is the negative lead and red is the positive lead of the polarized capacitor. Yes, you ...
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| Electrical conversion | 4/3/2005 |
Q: I am american and I live in BELGIUM. We bought a 220V hot tub which was supposed to be 220v European ...
A: I do not recommend what you are proposing. A hot tub needs special care to prevent a possible ...
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| Diode | 3/31/2005 |
Q: I've always assumed that the mark on a diode at one end indicates the cathode, and most diodes I ...
A: If it is a two-leaded device with a line at one end, the line always indicates the cathode. There ...
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| what are logic gate... | 3/30/2005 |
Q: what are logic gates
A: The most popular voltage standard is 5 volts, so I'll explain based on a 5 volt system. A voltage ...
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| A/D CONVERTERS | 3/21/2005 |
Q: HOW R U SIR. I WANA TO ASK U THAT WHAT IS MEANT BY DUAL SLOPE ANALOG TO DIGITAL CONVERTER AND HOW WE ...
A: A DS A/D converter uses an integrator with a voltage output that ramps up at a rate proportional to ...
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| line output/flyback tranformer | 3/15/2005 |
Q: In a CRT, the flyback transformer generates the high voltages for the final anode (output from LOPT ...
A: The flyback is only needed for blanking the return to the left side of the screen because that has ...
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| TV Blanking Interval | 3/9/2005 |
Q: Does the electron beam switch off during flyback (both horizontal and vertical). If the electron ...
A: Yes, your understanding of the scan is correct. The cathode is not turned on and off, and so there ...
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| Dangers and measurement of electricity | 3/7/2005 |
Q: Nyce, My name is Aravind Kannan. I am doing a project in high school which involves the use of ...
A: I know that 24 volts is considered safe for skin contact, but I don't know what voltage causes ...
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| electromagnetic wave energy | 2/23/2005 |
Q: I believe that the higher the frequency of the electromagnetic wave, the more energy it has because ...
A: You can transmit a given frequency by using more or less power. A small radio control airplane uses ...
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| Alr8 Dave, this is not a homework... | 2/23/2005 |
Q: Alr8 Dave, this is not a homework question!! Im a GCSE student and i am making an electronic ...
A: I assume that you have a digital BCD output and want to drive a 7-segment LED. There is an IC for ...
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| Air Compressor motor malfunction | 2/20/2005 |
Q: I have found an old air compressor marked "needs new motor" and I love learning about anything so I ...
A: There are a lot of different ways to make motors. Most are not made for disassembly. You will ...
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| Transformer and element hum | 2/19/2005 |
Q: Why do resistive heating elements produce a humming noise when running on AC? Different websites ...
A: Hum in a transformer could be greater with some DC, because the DC would create a constant magnetic ...
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| potential transformer | 2/19/2005 |
Q: I see transformers in the sense of the law of conservation, energy cannot be detroyed or created. If ...
A: If a normal power transformer (two or more isolated windings, iron core) is operating while the core ...
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| Lighting Technology | 2/18/2005 |
Q: I have a question and I'm not sure if it's something that you can help with but perhaps you can at ...
A: There was not enough information on either website to make a decision, although the LongArm website ...
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| modulator/mixer | 2/15/2005 |
Q: In diagrams of am and fm radio transmitters, you always see the modulator labelled as an IC, but how ...
A: In AM, the audio signal causes amplitude changes of a fixed carrier wave (for example, the carrier ...
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| 555 pin 4 and RFI supression | 2/12/2005 |
Q: I know that on a 555 timer pin 4 is RESET, with a 555 astable circuit, pin 4 is connected directly ...
A: With an astable or monostable connection, the reset pin is connected to V+. If you want to reset a ...
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| Variable gain control | 2/8/2005 |
Q: On a guitar amp there is a variable gain control which is another potentiometer, it is set high when ...
A: The amplifier could be designed either way. On my guitar amp, it has "clean" and "lead" settings. ...
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| LCD | 2/4/2005 |
Q: I have red contradicting articles on the web about how LCDs work. Some have said that when a DC ...
A: Some LCDs are transmissive, so that light only shines through when they are "on" (and the characters ...
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| Quartz Oscillator | 2/1/2005 |
Q: When a continuous pulling or compressing force is applied to a quartz crystal, a potential ...
A: When you bend or compress a crystal, it produces an instantaneous voltage difference, as you know. ...
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| Ballast | 1/30/2005 |
Q: A fluorescent lamp used to require a magnetic ballast. The lamp also ran on AC. If the ballast ...
A: The older type of fluorescent circuit used a starter switch (with a heater and bimetal switch. As ...
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| Transformer | 1/26/2005 |
Q: In a transformer where you can adjust the core (i've seen a few of these in Radio frequency ...
A: Inserting the core further into a transformer increases the amount of energy that can be transfered ...
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| transformer maintenance | 1/21/2005 |
Q: Our transformer rating is 6600V/230V, no problem with the incoming voltage however secondary results ...
A: I'm sorry, but I don't have enough information. That voltage is just a little out of what the spec ...
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| UK Electricity | 1/16/2005 |
Q: I just moved to the UK and am adjusting to, among other things, the electrical distribution system. ...
A: The simple "converter"s have only a series diode for operating heaters, AC/DC motors and such on ...
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| Led Question | 1/16/2005 |
Q: I am working on a project that i need some leds. i need 14 red leds (1.7V, 30 mA max, 1500mcd) to ...
A: You could use 2 sets of 7 LEDs in series, and connect those two sets in parallel to an 18 volt ...
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| Difference b/w 8086 & 8088 | 1/13/2005 |
Q: SirI want To ask You That in the begining 8086 Intel microprocessor came and it was 16-bit but when ...
A: The 8086 was intended for use in a personal computer (PC). The next in the series for PCs was the ...
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| Battery/electrochemical reaction | 1/8/2005 |
Q: Do batteries produce electrons in a circuit or move them round (provide them with energy to move)? I ...
A: A battery does not create more electrons. It causes the atoms or molecules with extra electrons to ...
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| Series circuit | 1/8/2005 |
Q: I did an practical experiment in my school. The experiment was to make a series circuit with three ...
A: Apparently, the assumption that each bulb has the same resistance was not correct. When a bulb ...
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| Telephones | 1/5/2005 |
Q: If a telephone's bandwidth is around 4khz, which is enough for adequate voice coverage, how come you ...
A: The telephone bandwidth includes the performance of the mouthpiece at one end and the earpiece at ...
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| sine wave generator | 12/24/2004 |
Q: my sine wave generator generates sine wave. but when is connected to circuit sine wave cuts in max ...
A: It sounds like the sine wave is being clipped because the signal level is too high for the input of ...
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| Electrodes | 12/17/2004 |
Q: This is Aravind, I am sorry for not phrasing my question right. This is the question I need the ...
A: You can connect the wires directly to the battery, but it is easier to do if you buy a battery ...
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| electromagnetic waves | 12/17/2004 |
Q: I understand that accelerating electric charge through air (spark gap radio) and acclerating charge ...
A: Electromagnetic waves can be generated at very low frequencies, but it requires a very long antenna ...
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| Electrodes | 12/17/2004 |
Q: My name is Aravind Kannan, I am a Freshman at Cedar Park High school. I am doing a semester project ...
A: I'm not sure that I understand your question. If the bacteria are contained in an electrically ...
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| Clock | 12/14/2004 |
Q: How does the clock generator in a PC actually work? Is it a piece of quartz crystal set to resonate ...
A: A clock pulse generator is an oscillator circuit that has an output going from logic zero to logic ...
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| bandwidth | 12/12/2004 |
Q: I understand FM has an audio base band bandwidth of about 20khz, is that restriction imposed by the ...
A: With an FM transmitter, you have a carrier frequency, for example 100 MHz. There is an input signal, ...
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| Waves | 12/9/2004 |
Q: If low frequencies travel further and higher ones are more directional, if i transmit at a lower ...
A: Lower frequencies can "go farther" only because they can be less affected by obstructions and the ...
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| electrical engineer | 12/7/2004 |
Q: do you enjoy what you do?
A: I don't know why, but this question just popped now. It looks like you sent it two days ago. Yes, I ...
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| Walkie Talkie | 12/5/2004 |
Q: How come walkie talkies, which operate on such a low freq around 49Mhz i think, have such small ...
A: The crystal controls the frequency, and does not affect range. The range is affected by the power ...
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| Antenna's | 11/30/2004 |
Q: Ive got a really nice FM transmitter, but the aerial is about 170cm (90Mhz) which is half ...
A: You can make it 1/4 wavelength, and it will work about 70% as good. You can make it work a little ...
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| dual-slope integrating ADC | 11/27/2004 |
Q: Based on what I've learned so far, the key relationship for such an ADC is: Vin / T1 = Vref / T2 ...
A: The digital output is based on T2/T1 * Vref. When T2 is very small, then the input reading it ...
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| Fm Transmitter | 11/24/2004 |
Q: Ive got a basic tank circuit and am modulating it with a 1khz square wave, but im finding when i try ...
A: There are a lot of possibilities: the main one one is , as you've said, a 1kHz square wave does not ...
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| IC7473 | 11/23/2004 |
Q: Erm, I got a dual JK Flip-flop - IC 7473(SN74LS73AN) but it seem like the ic can't work and I've ...
A: A 555 timer with 1k ohm pull up resistor will be able to drive the FF. Make sure that all other pins ...
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| How do I build an eletromagnetic field? | 11/20/2004 |
Q: Mr. Nyce, I am sorry if this is not your area of questioning, I was not sure. I am currently doing ...
A: Just so you understand the meaning of a magnet's north pole: If you take a long, thin, permanent ...
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| hexadecimal | 11/19/2004 |
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