walid Posted January 9, 2007 Report Share Posted January 9, 2007 Hioften have some friends with their remote control to to repair it. This requires that you have the examiner Cristal to ensure the validity of this piece. In the past, I was immediately replaced them with new, but I know I need to examine the crystal. Searched in the internet and I found this circuit and structure but did not work, therefore decided to understand it very well that to succeed when structure the next time. I deleted the 56p cap because I do not need to watch the freq. I know that the first transistor worked as oscillator and the o/p sig rectified by the two diodes to the final stage which will be ON if the first stage oscillate.My questions:1) is the 1st stage is colpitts osc.2) How the value of frequency depends on crystal?3)Why 680p and 150p caps, What if others these values? Quote Link to comment Share on other sites More sharing options...
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