This circuit was found in General Electric documentation from the 1980s. The circuit is intended to receive 50 kHz modulated optical signals. The components support modern equivalents.
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...