On Mon, 1 Nov 1999, Jon Petty wrote:

> I am looking for a circuit that will convert a 0-100 duty cycle at 15 Hz to a
> 0-5v analog signal to send to the ad converter. 50% duty= 2.5v.

  This is a "PWM DAC", essentially.  I have a circuit that I commonly use
for creating 4-20mA current loop driver signals that does this.  Requires
a dual op-amp, a couple of transistors (V-I converter) and a few resistors
and caps.  This thing is driven off a PIC output pin at 40Hz in most of
my stuff, but with some minor tweaks (double the integrating cap value)
it should work fine at 15Hz.  Making it do 0-5V is also a simple circuit
change.

   Send a private email if you want the schematic (as soon as I scan it ;)

  --Crow

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