Guest Terry S Posted January 27, 2003 Share Posted January 27, 2003 I need a square wave signal to my Autronic ECU. Does anyone know what type of signal a J spec rear wheel speed sensor gives? This is for the Traction Control BTW. Quote Link to comment Share on other sites More sharing options...
roboldham Posted January 27, 2003 Share Posted January 27, 2003 Best ask Pete Betts - I seem to remember him saying to me that it's usually almost (sic) a sine wave (magnet passing sensor) - but on my VVTi it looks like it could be kicking out square waves and confusing the box of tricks. R Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 27, 2003 Share Posted January 27, 2003 Thanks Rob. I'll wait for Pete to pop along......... Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted January 27, 2003 Share Posted January 27, 2003 just poped along.... The signal is a sine wave from the speed sensors generated from passing a magnet past a sensor. The magnet induces current into the sensor and this is turned into a voltage. The signal will be low amplitude at low speeds ( Problem with most electronics expecting a square wave input is that the ABS or wheel speed sensors generate an AC sinusiod waveform which they don't like and chances are it'll only start to roughly work when going quite fast (if at all) I made a signal conditioning circuit to adapt to Rob's ABS sensors for his VVTi in order to do the speedo conversion. The same thing would be needed here. The signal needs to be decoupled and biased around 2V. Now the AC waveform will move about 2V, and 2V is the triggering point for most digital circuits. Add a Schmitt triggered gate in between and you have yourself a 0->5V pulse generator from the wheel speed sensors. I guess you'll now ask ...... can I make one and how much? PM me on this. Regards Pete Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 27, 2003 Share Posted January 27, 2003 Many thanks Pete as always. You are a font of knowledge:D Quote Link to comment Share on other sites More sharing options...
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