injector driver simulator

[gui67]

Hello,
I hope I post in the right section.
A friend and I are building a injector test bench. It is now mecanically finished, we managed to open the injectors with 12V current.
here is a video of the bench with ID 2000 injectors:
http://youtu.be/6tKBRLRZWx4
Now I would like to build a circuit to drive the injectors. For accurate flow measurements we plan to use the injector outputs of the ECU (MS3X + P&H driver from Jean in my case) with the Jimstim to set the right RPM and PW, but we would like to find an easier way to drive the injector for different PWM and frequencies without taking the ECU from the car.

Is there a simple way to build a circuit that could generate the signal to ground the injector with variable frequency and PWM? (for example using potentiometers, we could then adjust the pots with an oscilloscope to get the desired settings.)

Maybe you can help me, because my knowledge in electronics is too weak to create something like that.
Guillaume

[racingmini_mtl]

Search for 556 PWM circuits. You should find something that fits your needs.

Jean

[xrattiracer]

very simple to code up an arduino or similar to do this too, if you wanted something that could be controlled with a pc or a small lcd screen and buttons.

[bcrx7]

Here you go, the Arduino code and the description: https://github.com/jrbe/injector_tester

[gui67]

Thanks for your answers,
Jean, did you mean something like that:
http://home.cogeco.ca/~rpaisley4/LM555.html#17
With a porentiometer instead of R2 to control the frequency?
And a transistor at the output for injector grounding?

Xrattiracer and Bcrx7, the Arduino idea is nice, but I think a bit too complicated for me. I would like to try it but I am afraid that I cannot manage to get it working. Do you know if that project is already working or if it is still in progress?
Maybe in a second step.