Circuit to turn a square signal to a VR signal

[katana]

This is an automotive type application. The engine has a variable reluctance sensor on it and I need to signal this to make an engine controller think it's watching an engine run. I have a micro which can be programmed to output any squarewave I like.

What sort of circuit can I use to turn a standard squarewave output signal into one that looks like VR signal.

thanks

 

[Rleo6965]

In automotive ignition system. Variable Reluctance or signal from Reluctor was converted into square wave pulse as trigger signal to ecu or cdi.

Why do you still have to convert square into sine wave reluctor signal?

 

[katana]

I need to have the engine controller believe it sees a proper VR signal. I'm not sure if a simple squarewave pulse will do it since I think the controller probably triggers on the 0 crossing.

In short I suspect there is probably a simple analog circuit with an inductor that can turn a simple squarewave into this sort of signal. I just don't have much expertise in analog circuits.

 

[john monks]

Driving a transformer through a capacitor with your square will get you there to some degree. Ultimately you will need an arbitrary waveform generator. The waveform you are looking at is what you typically see from a coil sensor from a distributor with a moving magnet.