The MOC3081, MOC3082 and MOC3083 devices consist of gallium arsenide infrared emitting diodes optically coupled to monolithic silicon detectors performing the function of Zero Voltage Crossing bilateral triac drivers. They are designed for use with a triac in the interface of logic systems to equipment powered from 240 Vac lines, such as solidstate relays, industrial controls, motors, solenoids and consumer appliances, etc.