Converting PWM output to 12v

Other Hardware General Electronics
1

Hi all,

I'm in the process of completing a drag car built and I would like to test a nitrous controller without having to run the car, the controller reads the RPM from a MSD ignition controller that outputs a 12v 20% duty cycle square wave.

Now, I can easily generate the correct PWM signal using a simple sketch up to 30khz, but I need to convert that to 12v, will a basic NPN setup be fast enough at 30khz?

Thanks

2

will a basic NPN setup be fast enough at 30khz

Yes it should be.

3

will a basic NPN setup be fast enough at 30khz?

Note that a "standard" level shifter with a an NPN ransistor (or N-channel MOSFET) and a pull-up resistor is an inverter so you'd need 80% PWM out of the Arduino.

4

an NPN ransistor

I am loving this new device, I an assuming that it makes things go rancid a lot quicker. :wink:

Sorry doug couldn't resist that one.

5

Thanks guys

DVDdoug:
Note that a "standard" level shifter with a an NPN ransistor (or N-channel MOSFET) and a pull-up resistor is an inverter so you'd need 80% PWM out of the Arduino.

Cheers mate, wouldn't have thought of that, I'll knock one up and test it on a scope before hand to see how clean the signal it is.

My long term intention is to be able to use it to replay runs using saved rpm data from the data logger and check the solenoids are all ramping correctly but for now, I just want to make sure I didn't mess up the wiring.