You will find that the kv of the motor is pretty high….A typical motor will give around 8-9 volts at a fairly high speed…8-9000 rpm…

If you have the patience to rewind you could get the voltage up and required speed down.

The current you can draw depends on wire gauge and how powerful the magnets are, but dont expect a lot..

Edited By John Rudd on 09/01/2019 10:05:09

I have used similar small permenant magnet motors as generators for my IC engines. You may find you need to use a belt drive to increase the speed, this was common in full size steam generating stations.

As a quick check you could drive one of the motors with your lathe of drill and see what output you can get.

This video is my 3cc engine lighting a few lamps:

**LINK**

I'v used small motors as generators on my hot air motors.

Ian S C

Can you explain this "simple op-amp crcuit" please? Perhaps you mean a boost mode switching regulator. A boost regulator will give you a constant output at higher voltage but there are limits to what it can do.

Cheap chinese version

https://www.ebay.co.uk/itm/MT3608-2A-DC-DC-Voltage-Step-Up-Regulator-Boost-Converter-Like-LM2577-XL6009/132860039749?

Robert G8RPI.

Ed, Jon's original enquiry was for the generator to do 'some work'. I understood that he would want to light some bulbs, drive a pump, or in some way show that the engine is producing power. With the very best circuit design, and with power opamps its going to be a self defeating goal.

If the opamps needed an external power supply then it would be like cheating, if the motor generates enough power to light bulbs then it could power the opamps too!

Ian P

Easy with a plastic backplate, but a crimped in metal one will need the crimps removing with a dremel grinder or similar.

@Ed, I don't think the way it would be used was specified just 'do some work'. My choice would be to daisy chain some LEDS and see how many it will run.

Neil

I have just seen a device that would be brilliant to show the capabilities of your engine and generator set. My granddaughter has been given a 'Plasma Ball' that was one of the items in the shop at the London Science Museum.

I have not examined it closely enough to find out any details but its about 60mm diameter and it can only contain a very small battery which it runs off for long periods before it is charged via the micro USB connector. (probably contains a 3.7V Lithium cell). I am sure a 540 motor will easily provide enough energy to create the plasma.

So a demonstration of old and new technologies, Live steam to live plasma

Ian P

Hallo Jon,

it is a good idea to discribe where you want to use the generator.

For example for my son, as he was younger, we made a Wilesco setup and then he want to have a generator for his small radio. I looked the same way as you , but you need with this type of motors a very high speed. We ended with an old printer stepper motor. This was used as a printer with 20 to 30 Volts or similar. Stepper motors are putting out as a generator ac volts , but with a simple diode and capacitor circuit and a voltage protector for the radio, it was possible to run the radio by about 500 to 1000 rpm of the wilesco steam engine. And that works fine. He had a lot of fun with it.

Werner