Cool tip!

John


--- Jinx <joecolquitt@clear.net.nz> wrote:

> > What do you mean by a "voltage doubler"?  Is this
> something
> > that would work off of the 3.3 v supply and able
> to produce
> > 25 mA?
> 
> Yes. 25mA isn't a big ask. You'd use 1 or 2 pins (eg
> the PWM
> module would be a convenient AC source that wouldn't
> affect
> code execution) directly or with a small FET (BS170
> ?) switch
> and a simple diode-capacitor doubler. Varying the
> duty cycle
> will vary the voltage out of the "doubler", bearing
> in mind diode
> losses. If Schottkys were used throughout, including
> one to
> isolate the 3V3 source, I'm sure this is a workable
> solution. You
> say the unit is battery-powered, so presumably this
> 3V3 is possibly
> higher (3V6 or more ?) and a series isolation diode
> will be of little
> consequence
> 



 
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