[sdiy] My 4069 attempt not working

[Nicolai Czempin]

Scott Gravenhorst wrote:

>Nicolai Czempin <n.czempin at gmx.de> wrote:
>  
>
>>What about them diodes, can I eliminate them for the time being?
>>    
>>
>
>It will work without the deFranco compensation (lower diode).  The one on
>top is necessary.  Powered by a "high" output from the schmitt trigger, the
>capacitor charges rapidly through the diode until the upper schmitt
>threshold is reached.  However, once charged, it can't discharge through
>that route because of the diode, so discharge is force to go through the
>current sink.  The cap discharges through the sink until it hits the lower
>schmitt threshold, causing another pulse which through the diode charges the
>cap and ...
>
>  
>
Ah! Thanks for clearing that up.