This circuit uses eight transistors, resistors, and capacitors to create an inverter that produces a 50Hz signal from a 12V battery. This signal is amplified through Darlington transistor pairs and fed to power transistors connected in a push-pull configuration. The output can power a small soldering iron when connected to a transformer with a 230V primary and 12V secondary. It provides a simple, inexpensive way to use a soldering iron when main power is unavailable.