Voltage to frequency converter
 

I have a 0-5V signal that I would like to convert to a negative pulse. Wanting to mimic a fuel injector, but it doesn't need much power behind it. The signal will control an injector. I have searched online but I can't make sense of the diagrams, so I am just looking to buy one already made. Where should I be looking? What should I be looking at paying?

sounds like you need a 555 timer, search for that and you should turn up something.

I agree with the above. The 555 is a very basic chip that does tons more than it is given credit for.

I think Vellman sells a few 555 PWM kits. You may need to swap the inputs to make them go negative.

I can make you a diagram if you know what durations you will need.

Jason, I need it to echo or simulate fuel injectors.

That is like saying you need a car with wheels.

What frequency pulse ?
What duration ?
What ratio of high to low ?

If 555 schematics are too much, I really reccommend getting a Velman. Easy to solder, some are prebuilt....... K8004: VELLEMAN INC.: Education & Hobby they list it as a Expert kit........
If you can use a knob this QKits Electronic Kits: MX033, PWM DC Motor Speed Control Module will work. It is also possible to replace the variable resistor with your 0-5V signal.

This mentioned signal 0...5V is an analog one and it is proportional to frequency, ok, but if we are talking about injectors you have to synchronize generated freqency to the position of pistons, right? If you write more about input and output signals I might help you with designing such a circuit. What is a source of that 0...5V signal, load for output signal will be a fuel injector, right? Can you write what type of fuel injector? Are you going to connect two IC engines in series and controll them with one ECU?