I have just built a generator with a stepper motor I found in a photocopier/printer (24VDC, 0.7A) and a transformer. Without load, the voltage is around 406 VAC. With a bulb (230 VAC, 18 W), the voltage drops to 240 VAC.

Can a voltage regulator or stabilizer be of any help in making this generator power a number of household equipments?

  • \$\begingroup\$ More details needed. What speed are you rotating it at and what is your energy source? Frequency will be VERY high compared to mains frequency - anything that depends on 50 or 60 Hz will not work. Your Voc/ Vload suggests you are close to max power at that speed. You MAY get 20-30 W from it. It is POSSIBLE that you can get much more with due magix but probably not (ie max current may be set by core saturation so Vload MAY be able to be higher with more speed so power up). Maybe. \$\endgroup\$
    – Russell McMahon
    Apr 27, 2015 at 11:19
  • \$\begingroup\$ Thank you Sir, The AC motor from the photocopier is spinned through the help of a 12 VDC motor. The AC output is incresed with a reversed transformer. Couldn't measure the speed nor frequency. I am just a electricity fan who is led by power irregularities to build my own generator. I will appreciate any suggestion to improve this generator. Many thanks, Bienvenu \$\endgroup\$
    – Venu
    Apr 27, 2015 at 13:08
  • \$\begingroup\$ You should have mentioned the WHOLE circuit initially. The reversed transformer makes a large difference t understanding what is happening. What are the original input and output vo;tages of the transformer and what is its VA or wattage rating and or what are its dimensions (l x w x h) and weight. This helps understand its likely power capability. The transformer may limit the power able to be handled. The motor is probably not capable of producing more than about 20 Watts. That makes it most suitable for small load like the light bulb you are using now. \$\endgroup\$
    – Russell McMahon
    Apr 28, 2015 at 6:32

1 Answer 1


A boost regulator could switch the voltage to something higher but at lower current.

A buck regualtor could lower the voltage but increase the current.

There is nothing, though, that will increase current and voltage at the same time continuously.
If you could do that you would have a perpetual motion machine.

As @Russel McMahon says, the voltages you mention say that the generator is pretty much maxed out powering an 18Watt light bulb. You might get a few more watts out of it before the voltage drops down too low for a normal line powered device.

Along with all of that is the fact that your gernator doesn't provide a regulated frequency, and probably doesn't deliver a clean sine wave - your devices won't like that very much, and might burn out from that or from over voltage since your generator doesn't provide a regulated voltage either.


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