transistor selection

Hi all,

Need a bit of help from those with lots of experience with transistors.

Firstly, this is what I am doing:
I want to measure the duty cycle of my cars fuel injector system.

So I am wondering what would be best - A PNP or a p type fet?

Suggest some model numbers for the job

I have a bc327 set up at the moment. I also have a diode running from the base to ground. I am a bit paranoid - considering the transistor could breakdown, and then pull the injector to ground all the time - It has happened to me before

Why do you need a transistor to "measure the duty cycle of my cars fuel injector system"?

A circuit would help explain what you are trying to do...

A cars fuel injector is like the coil of a relay connected with an npn transistor.

12V gets put on one end of the fuel injector, and the other gets pulled to ground.

I need to sample the pull to ground leg to measure the duty cycle.

I also need to make the sample a 5V signal.

I prefer to use a transistor instead of a voltage divider to get it to a 5V signal

Close thread. All is well