Truth be told !!!
Ok Guys, it's time for me to come on the level with you. I stated that the circuit I needed was for "hydro" so you would spend time helping me find the circuit I was looking for, instead of jumping all over me for being slightly crazy ! haha
Here's my actual application. We currently have a 2000 watt pv array that puts out about 17 amps at 120vdc. Open voltage it runs all the way up to about 203 volts dc.
While I'm hoping to eventually build a homemade inverter, I can not afford to purchase a commercial one, as they start out at over $6K
It occured to me, that I could at least demonstrate the PV's power output to friends and neighbors and get some limited use out of it, if I pulley drove a ac alternator with a 3hp 180vdc motor. I have played with this arrangement under controlled loads, but if the load were to be removed the system would over speed, I'd have ultra high voltages and probably throw the windings off of my alternator armature!
So while it's both impractical, and very energy wasting, If I were to put a dump load on the alternator to maintain it's voltage into a "safe level" I could get limited usage out of it (without the need for an electronic inverter) or even batteries. Friends and neighbors could also witness what PV's alone can do.
A better setup would be to drive an igbt brick with pwm to control the dc input to my 3hp drive motor. The pwm would be controlled by the alternator's frequency output. This would conserve energy and allow the unit to also run from a 120vdc battery bank at a later date.
Of course an 120vdc Electronic inverter is the ultimate goal. But hey 120vdc at 17 amps going to waste every day is more than I can take !
Yes Dominic, That's the circuit I think Ill try to modify for my own usage unless I can come up with something better suited. And I love your tag line ! I think that just about describes a lot of us. Haha
veewee77, Allan and Vtbsr, Thanks for your concern and desire to help also.
It shouldn't be so hard one would think. Just a glorified lamp dimmer with external feed back of some sort.
Now if I could just find something to plug my electric drill into !
John II