Voltage boosting a PWM signal?

Hi all,

I was wondering if anyone know if this will work (I have my doubts) I’m needing to use a PWM signal to get proportional control of a valve, I’m using a Mini Maestro as the controller with a channel set to servo, and the valve needs min 10.8V and I’m trying to avoid having to use 10.8V as the VIN for the maestro just for the valve. So I was thinking of using a Pololu Adjustable Boost Regulator 4-25V in between the servo output from the maestro and the valve, but as this is the signal wire that I’m going to use will it interfere with the PWM signal? Alternatively I could maybe use a Mosfet? any ideas?


The boost converter acts as a big lowpass filter, and thus the PWM would just give it less current to work with; you wouldn’t actually be able to see the signal on the other end.

The typical way of solving this is to use a MOSFET control circuit of some sort. Using a P-channel MOSFET is hard because you need to get the gate all the way up to 10 volts to turn it off. You might be able to do that with a pull-up resistor of 100-200 Ohms or so, and have the PWM drive the gate of a small N-channel that pulls the P-channel gate down to ground (and thus sees the current through the pull-up resistor.)