The ST04-30F1-5103 Zener Diodes Power Zeners Trankillers is a power trankiller manufactured by Shindengen. This device is used as a power supply voltage stabilization device, such as preventing overvoltage on the output of the power supply, by clamping the voltage at its reverse breakdown voltage. It gives an indication of the short circuit current and gives the voltage regulator or power supply a time to shut down safely in the event of an over voltage. This device features a four-position lead chassis, and a small-sized structure for minimizing chassis size and weight. It provides a low-noise, high-efficiency power supply power supply. It also features a built-in Zener diode, with a reverse breakdown voltage between 7.5V and 30V, making it suitable for a range of circuit and power supply applications.