This 600 kHz circuit is designed to locate a lost boat anchor. The circuit has a range of up to 10 meters. The transistor admits equivalent.
Originally in 1986, this circuit was developed to operate with microcomputers of the time like the...
This circuit for measuring bridges was found in American documentation from the 60's. Transistors are...
This SCR circuit activates a buzzer when triggered. The circuit is from a Popular Electronics from...