Q&A Forum
@admin Thank you for the response, Jostein, I found a wiring diagram for the alternator which I plan to use. It is 140 amp unit from a 2005 GMC yukon denali. The alternator has a solid state regulator attached to the back of the alternator. Please see attached schematic.
The vehicles powertrain control module uses duty cycle on pin C of the solid state regulator to control the alternator rotors field coil. Can I just hook up yourdyno PWM control to pin C of the alternators solid state regulator to control the field coil and thus control dyno braking?
I would also have a car battery hooked up to the alternator with positive hooked up to BAT terminal on alternator and the battery negative hooked up to the alternators metal case. Thanks for your help. If this arrangement would not work I think I understand how to use a high speed switching transistor as you describe.
Never mind this last idea, I don't think it would work out. I think I have a better idea I will run it past you when I have it all sorted out. New idea utilizes a pair of mosfet's in parallel to control the alternator field coil and the mosfets can be switched using PWM from YourDyno controller.
@admin Thank you for the response, Jostein, I found a wiring diagram for the alternator which I plan to use. It is 140 amp unit from a 2005 GMC yukon denali. The alternator has a solid state regulator attached to the back of the alternator. Please see attached schematic.
The vehicles powertrain control module uses duty cycle on pin C of the solid state regulator to control the alternator rotors field coil. Can I just hook up yourdyno PWM control to pin C of the alternators solid state regulator to control the field coil and thus control dyno braking?
I would also have a car battery hooked up to the alternator with positive hooked up to BAT terminal on alternator and the battery negative hooked up to the alternators metal case. Thanks for your help. If this arrangement would not work I think I understand how to use a high speed switching transistor as you describe.
You can use a transistor that shorts the output of the alternator, controlled by a PWM signal from YourDyno.
The H-bridge you linked to may work, but there was very little information on it. Attached is a drawing of a typical h-bridge. Current normally flows like the red line in the drawing. You actually only need 1 of the transistors in the h-bridge, so you can connect two in parallel if you use the h-bridge.
Can I just use a dc power supply to vary the voltage to the rotor coil of the alternator like some people would use a manual valve to vary water supplied to a water brake? I would still be using YourDyno controller for data acquisition. Saws would be tested starting out at wide open throttle and no load and then gradually bring in the load by adding more voltage to the rotor windings.