G4+ Thunder High side driven GP PWM

[007]

I haven't been able to find a way to generate a high side driven PWM output. I'd like to use this to implement alternator output control. Since the entire unit is grounded to the chassis, low side driven PWM isn't an option.

Using GP Output and setting a threshold voltage causes the output to keep thrashing on and off, and makes the idle really lumpy and the lights flicker.

[mapper]

If i remember right, numbers in Pwm table means:

0 % = 12V

100% = 0 V 

Means you have to flip your numbers in the table. You should check current requirements, too

[Adamw]

11 minutes ago, mapper said:

If i remember right, numbers in Pwm table means:

0 % = 12V

100% = 0 V 

Means you have to flip your numbers in the table. You should check current requirements, too

Yeah, I was just going to say the same thing...

The PWM Aux out is a low side drive, but it is pulled up to 12V when "off".  Depending on how much current the alternator control circuit needs it will possibly work as is without anything extra.  If that doesnot have enough grunt to drive it then all you will need to do is wire in an extra pull-up resistor.  

Something like this I would expect would be plenty:

[007]

Thank you. I'll try this with the pull up resistor. The other method didn't seem to work.