This ingenious circuit was found in a 1990s Popular Electronics. The oscillator is a 555 and the keyer uses an optocoupler in the configuration shown.
This circuit is designed to analyze the distortion of an audio signal. We found it in an article in...
The frequency of this unijunction oscillator is determined by the crystal whose maximum frequency is...
January 2017 - Texas Instruments' new TLVx172 operational amplifiers with Rail-to-Rail outputs can now be...