This is a typical circuit for an old microwave oven. We took it from an August 1973 Radio Electronics magazine, from an article that taught how to make repairs.
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...