Four-decade variable oscillator


Posted on Jul 27, 2012

The circuit consists of a variable current source that charges a capacitor, which is rapidly discharged by a Schmitt-trigger comparator. The sawtooth waveform thus produced is fed to another comparator, one with a variable switching level. The output from the second comparator is a pulse train with an independently adjustable frequency and duty cycle. The variable-frequency ramp generator consists of capacitor Cl, which is charged by a variable and nonlinear current source.


Four-decade variable oscillator
Click here to download the full size of the above Circuit.

The latter comprises a 2N2907A pnp transistor, plus resistor Rl and the potentiometer R2. Capacitor C2 eliminates any ripple or noise at the base of the transistor that might cause frequency jitter at the output.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Quick Multiconductor Cable Tester
help diagnose stator
Guitar pre-amplifier using uA 741
Water Activated Alarm
I have a 315bl excavator. Engine intermittently shut off on
BA313 ALC circuit diagram of a sound recording
Digital triac circuit diagram



Top