The purpose of this circuit is to produce a quick discharge on a shorted battery to attempt its recovery. The diode must be high current and the transformer too.
This receiver with two common JFETs was found in an old English documentation. The phone is...
This TTL circuit with the 7493 makes the binary count of the pulses sent by a flip-flop with the...
This circuit was found in a Popular Electronics from the 90s. The counter circuit is not common...