| Subject | Date Asked | Expert |
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| power supply | 11/28/2003 | Dave Nyce |
Q: If a filter capacitor in a full-wave power supply developes a DC short what would happen and why and ...
A: If the filter capacitor shorts, a high current will flow of the amount that can be supported by the ...
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| transistors | 11/7/2003 | cleggsan |
Q: I am having trouble with the FET amplifiers in the best way and what parameters to use in finding ...
A: I would like to see the entire circuit and the resistance values. But we can do it. Here is the ...
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| circuit testing | 11/6/2003 | cleggsan |
Q: If I have a series circuit with a DC source and say 4 resistors of varies ohms and I want to test ...
A: Most circuits; that is, for the sake of uniformity, are drawn to have a common or ground line at ...
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| Dear sir;
I intend to make... | 11/1/2003 | cleggsan |
Q: I intend to make a device like stepper motor driver or answering machine with microproccesor or ...
A: There are many hobby and circuits magazines and websites that can help you with this kind of ...
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| Liquid Conductivity | 10/24/2003 | cleggsan |
Q: I would like to know what kind of liquid solutions (ex: Lemmon Juice, Baking Soda, etc.) would ...
A: I think what you are asking is which liquid solution has the lowest electrical resistance and would, ...
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| Electrical Transformer | 10/8/2003 | Dave Nyce |
Q: Sir, I just want to know that why the TRANSFORMERS are rated in VA ( please explain in details ) ...
A: A changing magnetic field induces energy into a nearby conductor, this is called the Faraday effect. ...
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| Finding equivalent resistance | 10/5/2003 | Dave Nyce |
Q: How do I find the equivalent resistance in this circuit? /\/\/ is a resistor and --- is a wire. All ...
A: I'm not sure that everything lined up right as I received it, but I think I have it. Assuming that ...
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| Ceramic Fuse | 9/11/2003 | Dave Nyce |
Q: How do I convert fractional Amp ranges to decimal Amperages and not risk the integrity of the ...
A: I'm not sure that I understand your question. For a 1/8 amp fuse, you can use one rated for .125 ...
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| oscilloscope | 8/9/2003 | Dave Nyce |
Q: I am using the multisim 2001 program to learn how to test with the oscilloscope and I am testing an ...
A: Normally you would connect the A channel to the input side, B to the output side, and trigger on A. ...
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| impedance | 8/8/2003 | Dave Nyce |
Q: I am having trouble understanding how to find the impedance of the tank part of a circuit with ...
A: At the resonant frequency, the magnitude of the inductive reactance is equal to the capacitive ...
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| reduce voltage | 6/19/2003 | Dave Nyce |
Q: Could you please tell me how I could reduce a 24v power supply, so I could operate a 12v (13 amp) ...
A: This is a little difficult because of the 13 Amps. The circuit that reduces the 24V to 12V at 13 ...
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| conductive adhesive/epoxy | 6/7/2003 | Dave Nyce |
Q: It was hopeless but you saved me a lot of guesswork. Same computer project, the front panel of the ...
A: In an auto store, you can buy conductive paint that is used to repair rear window heaters when they ...
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| reuse a commercial LED display | 6/4/2003 | Dave Nyce |
Q: I'm putting a computer into an old stereo receiver/amplifier that quit amplifying a while back. The ...
A: Sorry I couldn't answer yesterday, the system kept saying that the site was busy. You have two ...
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| capacitors | 5/17/2003 | Dave Nyce |
Q: If I measure a capacitor with a ohmmeter and it reads 100ohms, what will this tell me about the ...
A: If a non-polarized capacitor reads a steady resistance, it is defective. If the capacitor is ...
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| Hi Dave, Thanks for all the... | 5/13/2003 | Dave Nyce |
Q: The question I have today is about power generation. I was reading that when power is generated ...
A: If the 3 phases are already ground referenced, then a circuit breaker would open if you shorted a ...
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| 230-250 volts vs 110 | 5/4/2003 | Dave Nyce |
Q: I have a sewing machine that was made in England. It is: 230-250 volts and 0-25 amps. I have ...
A: There is a surge current when starting this type of motor, so the maximum surge current is shown. ...
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| Micro wave | 4/8/2003 | Dave Nyce |
Q: I am doing a science project for my eight grade class next week. I am interested in just why a ...
A: The microwave energy is electromagnetic energy with a frequency of over 1 GHz, that means it has ...
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| sensor and switch circuits | 3/24/2003 | Dave Nyce |
Q: I am a graduate student in Architecture and have the following question; I have a room with two ...
A: I'm not sure I understand why you would need a motion detector or a computer. Unfortunately there is ...
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| Computer Engineering Degree | 3/11/2003 | Dave Nyce |
Q: I am 16 and wishing to go into computer engineering. My marks arnt that high, so first im not sure ...
A: An engineering curriculum includes a substantial amount of math and science. If these subjects are ...
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| COMPLETE discharge | 2/5/2003 | Dave Nyce |
Q: The words printed on my rechargable battery(Ni-H) of panasonic says that "for consideration please ...
A: Yes, if the battery no longer provides power, it has "complete discharge". But, if you are going on ...
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| one-minute timer | 2/4/2003 | Dave Nyce |
Q: My nephew is to make a one-minute timer using household materials. Any suggestions you can give ...
A: How about taking a cone-shaped paper cup (the kind from some office water coolers)and cut a small ...
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| High Frequency generator | 1/27/2003 | Dave Nyce |
Q: My 12-year old daughter wants to test the hearing range of her pets for the science fair. I have an ...
A: I'm afraid that it might be a little more difficult than it may seem. A sine wave can have a ...
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| CE | 1/21/2003 | Dave Nyce |
Q: THESE LETTERS SHOW UP ON MANY, MANY PRODUCTS THAT I BUY NOWADAYS. IN MY EXPERIENCE, IT'S BEEN ...
A: The letters CE stand for the french words Committee European. That is a set of regulations on ...
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| Hi Dave, I am replacing the... | 1/6/2003 | Dave Nyce |
Q: I am replacing the cpu cooling fan on my computer and the power wires come from the fan, then are ...
A: It is a ferrite ring and the wire coiling around it makes an inductor. It is for the purpose of ...
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| Voltage and Current - Basic Question | 1/2/2003 | Dave Nyce |
Q: The power socket on my laptop computer is expecting 16v 2.5A. I have a car/auto adapter which ...
A: "Delivering too much amps" is not a problem. The 3.8A rating of the power supply means that it is ...
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| plug | 11/8/2002 | Dave Nyce |
Q: For what reason the plugs of normal electronics(e.g. radio,TV) have TWO processes(made of metal)? ...
A: I'm not sure what you mean by "process". If you mean the 2 or 3 metal contacts of the power plug, ...
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| Operational Amplifiers.... | 10/18/2002 | John Penton |
Q: I have done an experiment with the Operational Amplifiers as the Integrators and Differentiators. I ...
A: The circuits are called integrators and differentiators because of their relation to basic calculus. ...
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| use of relay | 10/13/2002 | John Penton |
Q: John, quick question. I want to use a relay in an automotive application. I want to switch 12V ...
A: I don't know very much about car wiring, but I can tell you about the electronics. A relay will ...
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| kirchoffs law (I think) | 10/12/2002 | John Penton |
Q: this is a sort of post a level question. there is a circuit with a diamond of resistors (R1-5) and ...
A: You are correct in thinking that you need Kirchoff's Law The way I would do it is this: ...
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| RECORDING | 10/5/2002 | Dave Nyce |
Q: If you have a turntable and a tape deck,and hook up the turntable to the deck line-in directly can ...
A: The output from a truntable comes directly from the tone arm pickup. With a magnetic pickup, that is ...
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| How Hard to Drive PNP? | 10/2/2002 | Dave Nyce |
Q: My apologies for asking a time consuming open ended question the other week. I got carried away, ...
A: The gain of a transistor is usually specified to range over a 3 to 1 range at room temperature, and ...
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| considering electrical engineering major | 8/1/2002 | Dave Nyce |
Q: I think I want to go into engineering, but there's so many kinds I don't know which one to go into. ...
A: I think you have more opportunities when majoring in electrical engineering. Also take the courses ...
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| Why Current Flow So Small Here? | 7/26/2002 | Dave Nyce |
Q: Dave, I've prototyped another part of the circuit I'm designing. The two transistors in question ...
A: With your circuit, you should get about 4.3 volts to the LED circuit. If it is a red LED, it has a ...
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| Monitor | 7/23/2002 | Dave Nyce |
Q: I'm not sure you'll be able to help but here goes: I have the screen from a laptop computer which ...
A: Laptop computer screens are not made to communicate over standard protocols as monitors are. They ...
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| Advice on LED Circuit | 7/16/2002 | Dave Nyce |
Q: Dave, I have a project where I need to flash ten LEDs in succession in a repeating cycle, like an ...
A: The normal way to make a light chaser is different from your request. Usually, every fourth light ...
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| A simple Question | 7/1/2002 | Dave Nyce |
Q: Sir , I am a 22 boy , an assistant Engineer of Audio Engg... Would you mind answering my ...
A: When the range of measurements is too wide to use a linear scale, a logarithmic scale based on the ...
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| Role of Vbc in NPN Transistors | 6/20/2002 | John Penton |
Q: I'm making headway with electronics. I have a question on NPN transistors - what happens if Vbc ...
A: First point to make: you show Vbe as being 2V - in practice this will never be possible. If Vbe was ...
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| signal switching circuit | 6/14/2002 | John Penton |
Q: my background is in mechanical engineering so I have a good grasp on physics and most things ...
A: Sounds like a simple logic problem to me. Get some gates and arrange them to produce the desired ...
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| dc motor | 4/30/2002 | Dave Nyce |
Q: The armature of a 220-V dc motor draws 15 A when operating at full load and has a resistance of 2.1 ...
A: 220 volts / 15 amps is 14.6 ohms. You subtract the armature resistance from this, because this does ...
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| 8051 sensors | 4/27/2002 | Dave Nyce |
Q: I'm finishing my 4th year Electronic Engineering degree next year and have to do a final year ...
A: I listed myself as being on vacation last week. Somehow the website didn't pick it up. Sorry. There ...
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