This circuit was found in a 1967 US documentation. The circuit applies to modern general purpose transistors. The circuit has no offset. The power supply must be symmetrical.
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...