Hi, I have not tried the circuit. It does appear to be a blocking diode. I am still trying to use a N channel. I have purchased some FOD3180 gate drivers to use with a isolated power supply. I will be doing some work on the circuit over the weekend and will post results when available.
Lets find renewable solutions to reduce energy cost
GoVertical wrote:Hi, micro controlled P channel buck converter battery charger. http://www.zilog.com/docs/z8encore/appnotes/an0137.pdf
Hi, micro controlled P channel buck converter battery charger.
What is the purpose of D2 on page 11? Is it just to make sure the battery doesn't backfeed Vp if Vp falls below Vbatt or is there some other function that I am missing?
Hi, I found the reference, the diode across the gate resistor increases the turn off speed.
Hi, here is interesting circuit that is very similar to project I am working on.
It has blocking diodes after the inductor and diodes across the gate resistors.
I am not sure what the diodes across the gate resistor do???? comments welcome
Greetings, isolated power supply modules have arrived. Hopefully this will prevent the 555 timer from shutting down when a 12 volt battery is used as a load. I did some informal experimenting and noticed that very small changes of the duty cycle control signal had dramatic affects on the required torque for the PMA under manual operation.
Hi, when comparing the waveforms of the two gate driver circuits the circuit without the IR2117 triggers the mosfet all the time.
Video without IR2117 in gate driver circuit:
mosfet Vs is top waveform:
The circuit using the IR2117 only triggers the mosfet when the PMA provides a input voltage.
Video using IR2117, bottom waveform is mosfet Vs:
Side note: I am using a bench power supply for the isolated power supply for the gate driver circuit. There is no IR2117 in the circuit. I suspect because the gate driver circuit output is not riding on Vs it is placing a limit on the output.
Side note: I replaced the battery with the 50 watt halogen and was unable to illuminate the light. I was expecting to able to reproduce the earlier results but I was not. Not sure why.
Hi, I have verified that using a isolated power supply for the gate drive circuit will turn the N channel mosfet on and off in a Buck circuit configuration with a 12 volt battery as a load. I configured the gate drive circuit with a 555 time and used a Schmitz triggered nand gate as a inverter. The 555 timer was configured with a variable 1 meg ohm pot so the duty cycle could be changed. The shorter I set the duty cycle the easier the PMA was able to spin and produced a very high voltage at Vin. Positive current was flowing into the battery. Under manual operation the best I could achieve was 0.7 amps flowing into the battery. The circuit will definitely benefit from using a microcontroller to adjust the duty cycle. At this time I am starting to work on paralleling the mosfets and adding a microcontroller to the system. Comments welcome