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Re: gEDA-user: Capacitors



At 04:49 15-2-2006, you wrote:
Stuart Brorson wrote:

If your application is to create a frequency stable oscillator, your
best bet is to build a crystal oscillator at some higher frequency,
and then count down the oscillator output to the frequency you want.
That's the most stable and accurate method, and crystals are cheap and
easy to use.  You can build a simple crystal oscillator with two 7406
inverter gates and a crystal (+ resistors).  Then the counter can be a
74163, or just get a CPLD and program it to implement whatever
frequency/function/pulse duty cycle you wish to generate.

Stuart




i Actually build a pulse generator the other day using a 555 timer and a electrolytic, it wondered all over the place i tried a tantulum bean cap it was better but still wouldnt stay on frequency.

Marc :)





anyone ever build an oscillator using CMOS inverter (2 in series) and running them in linear region?

Check out http://www.fairchildsemi.com/an/AN/AN-118.pdf on CMOS oscillators. They like odd numbers of CMOS gates - they won't lock up ...


--
Bill Sloman, Nijmegen