Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The power supply is according to the relay with voltage up to 12 V.
The figure shows three circuits for using headphones in amplifiers with speakers that do not have...
In this charger, the charging current is basically limited by the LEDs. The transformer is a low...
This configuration is from an old integrated circuit manual. The circuit can be applied to modern...