- I'm wondering if it is at all possible to get 120 / 240 volt AC single or three phase current from an auto alternator.
- Mike
Yep, you can. I would be happy to answer any questions that you might have in this if you want. Try this site if you desire to see this being done by someone already;
Spinning an alternator faster will give you more voltage, but one must consider that you are affecting the frequency as well. The faster it goes, the higher the frequency. Now when in use with the diodes in the alternator, it does not matter. Nor does some equipment that you may be powering care about it. But frequency dependent equipment, such as Florescent lighting, Televisions, and electronic equipment will have a cow with it. The best thing to do is up the amount of field current for it, but even that has limitations (as it was originally not wound for it). A simple formula for determining how fast to spin the alternator is to know the amount of poles in the alternator (I presume you desire 60hz AC);
speed = (Hz * 120) / poles
Frequency dependent equipment, such as Florescent lighting, Televisions, and electronic equipment will have a cow with it. Oops, I forgot something. Before someone says something about "I run my TV on 100 hz and it's ok", I need to add something. Yes, you can run some TV's at higher frequencies as well as some stereo's. It is dependent upon the equipment having a transformer, stepping down the voltage and using DC voltage for running the main circuitry off of this voltage. A good part of modern units sold today do this. However, my point remains.
Yes, you need to do three things, assuming the alternator windings are not modified: