- Published in issue 7/1996 on page 100
32 kHz oscillator
A standard CMOS oscillator IC does not work with a watch crystal (32.768 kHz). At best, it starts to oscillate when the supply voltage is switched on, but as soon as the voltage rises to its nominal value, oscillations cease. The solution is simple and consists of adding a resistor between the crystal and the IC (R2 in the circiut diagram). Once this is done, the oscillator works fine and is not fed too much energy (which would cause it to give up the ghost within a short time). capactor C2 may be a trimmer to enable the frequency to be set accurately.