This circuit is from a Popular Electronics from the 90s, consisting of a repeater relay for remote control of TV, which today can be done by Wi-Fi or other simpler resources.
This effects circuit can be used with microphones or guitars. The circuit is from an American...
This circuit generates pulses whose frequency depends on C1. The circuit can be powered by...
I found this circuit in a 1998 publication, but as all components are common, it can be easily...