Experiment - Simulating VR Signals

Over the last couple nights i've been looking at creating some simulated variable reluctance sensor signals.

The scope picture above shows the finished crank and phase signal waveforms being output from the bread-board circuit into channel 1 & 2 of the oscilloscope.

Although I was quite pleased with the results it would be nice to develop the project a little more perhaps when I have more time to do so.

The circuit consisted of a small PIC uC that outputs the desired shaped waveform into a 6 bit resistor ladder DAC;   then the DC signal was fed into a single operational amplifier which negatively offsets the DC signal to create a nice AC signal;  after that the signal is simply multiplexed to create both the crank and phase.





Once I had increased the total number of sample points in my waveform the shape started to look much better.

As you can see I used quite a lot of trimmer POTs;  I couldn't find any 2R values in my parts box, so instead of using two-of  the same value Rs,  I just used some cheap POTs I had.

Overall the circuit worked well.