[sdiy] CMOS clock problem

[mark verbos]

um, duh.

I fixed it. Turns out I was taking the output from the wrong spot. I  
tapped it at the gate with a resistor on it's output rather than the  
one with the cap. I also had the 2 input pins on the gate with the  
cap after it tied together, instead of one to ground. Buchla did this  
and it seemed to work for him, but when I changed that to one input  
to ground it started working perfectly!

Thanks guys!


Mark







On Apr 22, 2008, at 10:11 AM, harrybissell at wowway.com wrote:

> Do you have a schematic ?
>
> I'm assuming its the traditional two-gate oscillator with
> one capacitor and two resistors.  One resistor and the cap
> sets the frequency, the other resistor is in series with the
> gate input to stop the input diodes from being too much of a pain
> in the @ss.  The resistor to the input should be about 10x the size
> of the frequency determining resistor.
>
> It could be that loading stops it from starting... is the output
> buffered ???
>
> H^) harry
>
>
>
> On Mon, 21 Apr 2008 16:44:43 -0400, mark verbos wrote
>> Hi,
>>
>> I have a high frequency clock made out of a couple 4001 gates in my
>> quantizer module. It doesn't like to start clocking when I turn it
>> on. Then I touch the pins with the scope probe and it starts going.
>> I  tried adding a 2.2M resistor to ground on the pin where the cap
>>  connects and I got it to start if I plug the connector in while the
>>  cabinet is powered up, but if I power cycle it while plugged in
>> it's  not oscillating. Is this something to do with the order that
>> the  power rails are coming up? It's only using +15 and GND, so I
>> don't  see how it could.
>>
>> Any ideas? I'm lost.
>>
>> Mark
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>
>
> Harry Bissell & Nora Abdullah 4eva
>