Based on the CA3140 IC, this circuit was found in the June 1986 issue of Radio Electronics. Sensitivity adjustment is made using a trimpot in series with the sensor.
This single pulse generator, loss detector, or peak detector was found in an old General Electric...
This PLL with operational amplifiers was found in 1969 documentation. The configuration can be...
This circuit is from the factory manual of the LM202, an uncommon operation today. It shows how to...