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Subject: lazy triangle
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Date: 08/25/03 at 7:47 PM
Posted by: aldor
E-mail: aldor[AT55]coam.net (replace [AT55] with @ to reply)
Where can I find a triangle wave generator circuit that will be stable down to .5 Hz? I have tried the 555 solution (pin 2) but adjusting the frequency distorts the waveform. I tried a intergrator on the square wave output but is is only linear at the frequency it is designed for. Varying the frequency of the square wave demands different intergrator components. I looked at the 038 waveform chip but it requires a dual supply. What I am trying to do is drive a Perkin Elmer LED/LDR package to sweep the LED current thereby sweeping the LDR to adjust the frequency up and down on a driver I designed that cannot have any external voltage on it's timing components. PWM on the LED doesn't work as the LDR passes the pulsing LED energy on to the timing circuit.
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