What makes PhotoMOS® technology so successful?Modern semiconductor technology enables fast, quiet, bounce-free switching, even in miniature sizes. PhotoMOS® relays nevertheless enjoy an almost unlimited lifetime if used according to the specifications. Moreover, they are extremely reliable, unaffected by vibrations, and their ON-resistance remains stable throughout their entire lifetime.
Light emitted from an LED on the input side passes through an isolator permeable to light and is detected by a solar cell. Via a trigger circuit, the solar cell's output voltage controls the gates of two source-coupled MOSFETs at the output. This arrangement allows PhotoMOS® relays to switch both AC and DC loads. The integration of MOSFET technology in PhotoMOS® relays differentiate them signifycantly from semiconductor relays with triacs or transistors at the output.