Bad Dynamo?


Active member

Aug 7, 2016
Richmond, Vermont, USA
you only need 10 VAC as the input to a full wave bridge to get 14 VDC
you need somewhat less than 20 VAC into a single diode to get 14.5 VDC

You can check out he original B&S patent dating to 1973 for the basis of all 'rectifier/regulators made since then and Byte Magazine for Steve Ciarcia's great article on how to build power supplies.
What you say above only holds true for AC voltage measured with a "True RMS" meter. Most folks do not have access to such a device. Instead, their AC meter may measure "Peak to Peak" voltage.

If I recall my electronics training (40 year ago) one must convert "Peak to Peak" voltage to "RMS" using mathematics.... otherwise, the numbers you posted are inaccurate.

I guess what I am saying here is AC volts (peak-to-peak) CANNOT be rectified into MORE voltage DC. It is not mathematically possible.

Most equipment I work on will measure more like 20+ VAC out of the alternator/generator. Three-Phase units can be more complicated.
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