ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Project

Kenbo, you are trying the car alternator at the moment i understand ?

You need to excite the field winding via a 12 volts supply, through a 3 watt lamp otherwise nothing will happen. ( perhaps 0.78 Volts )

The stator windings of an alternator have not got enough remanent magnetism in them to create enough flux for self excitation.

At relatively low speeds you should be able to generate a couple of Ampères.

you could switch to a generator from an old volkwasgon or a tractor.

Hi, all.

I have done a quick voltage measurement with a small 12 pole motor i have, base on similar principle, with permanent magnet in outer rotor.

By turning the shaft by hand quickly, then taking the photo, at about 100RPM it generates over 8 volts ac.

The big washing machine motor should work very well, The problem here is to get a proper bearing to center the rotor. The washing machine bearing was impossible to remove from the machine (corrosion on the drum) and was left on site.

I use this in my workshop to quicky advance low voltage steppermotors in kWh counters to check if they advance correctly.

http://farm1.static.flickr.com/181/457283590_eff2827b23.jpg Tacho gen. Open

http://farm1.static.flickr.com/202/457283588_619a490103.jpg Tacho gen. 8.24 volts ac

Regards, Raymond