Hi,

I have a Magnetic (VR) sensor signal from which I want to extract a 0-5 volt square wave representing the zero crossings. One side of the sensor is already connected to ground. Signal is AC and 3V top to top.

I think best way to do this by adding a DC voltage and window comparator, but I need to know to design the circuitry. Does somebody have example circuits for parts or the complete design to get me started here.
Let me know if there are other ways to get this done ( IC's, discrete parts)

Thanks,
René

 

A simple comparator should do it, something like an LM311. Keep the ground reference for the input.

If you don't have a negative supply available, you can use a 7660 or MAX660 etc. to produce one.

 

What is the frequency range of the signal from the sensor? What is the waveform?

 

See the attached for a reasonably easy approach using a dual or quad comparator that will operate using a single 5v supply.

If your application is automotive, use an LM2903 dual comparator.

If you use a quad comparator, be certain to ground the unused inputs, or you will have problems.

Adjusting the values of R2 and R3 will change the trigger points. If you use too small of values for them, the triggering may be rather flaky.