AboutDave Nyce Expertise I have been an electronics engineer for 25 years. I can answer questions on analog and digital circuits and my specialty is sensors.
Experience I am the inventor on 23 US patents, and also some foreign ones. Developed sensors for over 25 years. Licensed private pilot (airplane and rotorcraft), have HAM radio license. I'm not an expert in computer networking.
Expert: Dave Nyce Date: 4/22/2008 Subject: Voltage regulation
Question Thanks Dave,
My original idea was to use the stator and regulator from an old motorcycle, but 1/8" not enough space killed that idea. Load on the generator will be 40W in lighting, 10 to 15 watts in CD player and possibly a small 12VDC cooler.
I expect to get about 40 to 50 VDC from the DC Motor at a peak of 5000 RPM on the boat motor. I didn't consider any voltage drop across the inline Diode or from the wire gage.
Thanks for your time.
Answer The cooler probably takes at least 40W, so your load would total at about 100W. If it is providing 40V and you linearly regulate it to provide 12V at 100W (using a resistor to drop the voltage as needed before the regulator), then the generator has to provide over 300W at 40V in order to get the 100W at 12V. I don't envision any normal 130VDC motor being used as a generator to be able to accomplish that.
An alternative would be to use a switching regulator, but I don't think there are any ICs available to do that directly, so a circuit would have to be designed to do that.
Sorry that I don't have any simple answer for you.
