Crystal tester


Posted on Jul 14, 2012

Transistor Ql, a 2N3563, and its associated components form an oscillator circuit that will oscillate if, and only if, a good crystal is connected to the test clips. The output from the oscillator is then rectified by the two 1N4148 diodes and filtered by CI, a,01 µ capacitor. The positive voltage developed across the capacitor is applied to the base of Q2, another 2N3563, causing it to conduct. When that happens, current flows through LED1, causing it to glow. Since only a good crystal will oscillate, a glowing LED indicates that the crystal is indeed OK.


Crystal tester
Click here to download the full size of the above Circuit.

The circuit is powered by a standard nine-volt transistorj*adio battery and the SPST pushbutton power-switch is included to prolong battery life.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    System Modeler
    ir remote controlled switchboard rc5
    make circuit diagram
    1 Hz Pulse Frequency Generator with 555
    Experimental Pendulum Clock
    Practical Transistor Circuits
    APPLIANCE TIMER
    Loudspeaking radio receiver with a bridge amplifier powered by free energy



    Top