[sdiy] 4069 VCO to get started? My answer

[René Schmitz]

Nicolai Czempin wrote:

> Wow, I'm really looking forward to building and fully understanding that 
> 4069 cicuit one day. That day may not be that far away :-)
> 
> What puzzled me was not the general idea of an integrator or 
> Schmitt-Trigger. What did so was that the circuit showed the building 
> blocks simply as digital inverters. And I was wondering how on earth an 
> inverter can be one thing in one part of the circuit and another thing 
> elsewhere.
> So perhaps to make it clearer the symbol in the schematics could be 
> changed to reflect the functional usage.

The gates only become integrators or schmitt-triggers by their external 
components. Just like with OPs. Infact you can think of the gate symbol 
as a poor mans opamp, which has its + input tied to Vcc/2 internally and 
the only the - input brought out.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159