New idea sawtooth generator

Rick Jansen sscprick at
Mon Jul 10 09:52:38 CEST 1995

I just had a new idea to get rid of the discharge time in 
a sawtooth generator. Why not take TWO integrating capacitors
and switch the charging current and output for each half of 
the wave. This way one capacitor gets linearly charged while
the other can be relatively slowly discharged. It sure will 
be utterly discharged the moment the other integrator reaches
peak level. I propose to use 1% styroflex capacitors for this
purpose, which are easy to get.

Each integrator has its own comparator, one controlling the set,
the other controlling the reset of a flipflop. The Q and !Q of
the FF control some 4066 switches.

There's a gif of this in:

I hope switching of the charging current works with 4066 switches. 
Usually the switching of currents is tricky, but it might work 
in this case. The other thing is that there still is the reaction
time of the comparator/FF/switches. It can be compensated with a 
potmeter for each comparator, but that may get difficult to adjust,

Rick Jansen
rick at
S&H's a module and s&h's looking good

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