Chongo
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The knock sensor is fitted to check the ignition timing at the optimum moment. An engine gives it's maximum power if the ignition timing is on the pinging limit. During pinging a specific vibration frequency is set up in the engine of approx. 7.5 kHz. A knock sensor recognizes this specific vibration and passes a signal to the control unit. This sensor signal is raised by a piezo-crystal.
Piezo is a material that raises an electric current if it comes under mechanical pressure. The higher the pressure, the higher the current produced. Using this sensor the engine management system can recognize the pinging of the engine and adjust as necessary the ignition timing together or separately for each cylinder. Most processors control the ignition timing caused by pinging in increments of approx. 3 degrees ******** per data stream. If the engine no longer pings, the ignition timing in stages of approx. 0.5 degrees will be advanced until the normal value.
Hope this helps............ Chongo
Piezo is a material that raises an electric current if it comes under mechanical pressure. The higher the pressure, the higher the current produced. Using this sensor the engine management system can recognize the pinging of the engine and adjust as necessary the ignition timing together or separately for each cylinder. Most processors control the ignition timing caused by pinging in increments of approx. 3 degrees ******** per data stream. If the engine no longer pings, the ignition timing in stages of approx. 0.5 degrees will be advanced until the normal value.
Hope this helps............ Chongo
