Sunday, June 20, 2010

32.768 KHz oscillator using a watch crystal


Below are a couple circuits you can use to produce a 32.768 KHz square wave from a common watch crystal. The output can be fed to a 15 stage binary counter to obtain a 1 second square wave. The circuit on the left using the 4069 inverter is recommended over the transistor circuit and produces a better waveform. The single transistor circuit produces more of a ramping waveform but the output swings the full supply voltage range so it will easily drive the input to a CMOS binary counter.





http://www.bowdenshobbycircuits.info

1 comment:

  1. Regarding the transistor circuit, there is a mistake, the 3M3 resistor should be connected between transistor's base and collector.

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