Circuit from behind the spider webs...

Thread Starter

Externet

Joined Nov 29, 2005
2,223
Built this I cannot remember when, for I cannot remember why, and does I cannot remember what.
Found it with its schematic attached, and of course, untitled...:oops:

Can you help with what it does ? In my last brain transplant got a refurbished one, not recommended to any.
P1010633.JPG
 

RichardO

Joined May 4, 2013
2,270
Square wave oscillator with both duty cycle and frequency adjsutments. Note that the adjustments probably interact with each other.
 

DickCappels

Joined Aug 21, 2008
10,185
I think its possible to pad the duty cycle pot so it doesn't.
You can certainly minimize the duty cycle pot affecting the frequency by making the duty cycle pot much smaller than the frequency pot. For example the duty cycle pot could be 10l while leaving the frequency pot 500K. The maximum frequency shift resulting from changing the duty cycle would be (off the top ofmy head) about 1% (or
 

Thread Starter

Externet

Joined Nov 29, 2005
2,223
Hooked to power, produces alternate pulses with slower decay.
-------|\---------|/---------|\--------|/--------|\--------
Period adjustable from 4 to 10 seconds.

Disconnecting the 10uF capacitor, produces a seemingly pure sinewave. One potentiometer controls symmetry and the other, amplitude. Frequency at 50KHz.

Still cannot tell what I did this for. Any NEW brain available for transplant ? Will pay well.:rolleyes:
 

bertus

Joined Apr 5, 2008
22,278
Hello,

In the current configuration, the duty cycle will vary from 0-100 % when the frequency pot is at 0K and from 33-67 % when the frequency pot is on 500K.

Bertus
 
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