We found this solid-state relay circuit that can function as a shield in a Radio Electronics magazine from December 1989. The optocoupler is a phototransistor type.
This non-inverting AC amplifier was found on a Popular Electronics. The setting applies to any...
This small inverter came out in an Argentine magazine from the 1970s. It can also be assembled with...
The figure shows how to use a CMOS amplifier as a crystal-controlled oscillator. The circuit is...