This Velleman Quad Triac Switch Card Kit can control up to 4 high-power circuits from a low-power drive circuit. Relays are usually used to switch AC voltages by means of an electronic control because of their simplicity. However, when switching occurs too frequently or too quickly the life time of the contact points is shortened considerably. With the K2634 triac switch card kit this can be solved perfectly by replacing the relays with a triac. Using optocouplers, the entire interface network remains electrically isolated from the voltage that has to be switched.