A GFCI (Ground Fault Circuit Interrupter) is designed to prevent electrocution by detecting the leakage current, which can be far smaller (typically 5–30 milliamperes) than the currents needed to operate conventional circuit breakers or fuses (several amperes). GFCI's are intended to operate within 25-40 milliseconds, before electric shock can drive the heart into ventricular fibrillation, the most common cause of death through electric shock.

The method to synchronize light to music based on time durations and triggers.

A 64 channel controller with basic ON/OFF capabilities. Normally gets its input from the parallel port of the controlling computer. No status LEDs, inexpensive/simple to build. Developed by Robert Jordan (RJ).

Electrical circuits may be connected to ground (earth) for several reasons. In mains powered equipment, exposed metal parts are connected to ground to prevent contact with a dangerous voltage if electrical insulation fails. Connections to ground limit the build-up of static electricity when handling flammable products or when repairing electronic devices.