Teccor brand Quadrac devices are triacs that include a diac trigger mounted inside the same package. This device, developed by Littelfuse, saves the user the expense and assembly time of buying a discrete diac and assembling in conjunction with a gated triac. Also, the alternistor Quadrac device (QxxxxLTH) eliminates the need for a snubber network. The Quadrac device is a bidirectional AC switch and is gate controlled for either polarity of main terminal voltage. Its primary purpose is for AC switching and phase control applications such as speed controls, temperature modulation controls, and lighting controls where noise immunity is required. Triac current capacities range from 4A to 15A with voltage ranges from 200V to 600V. Quadrac devices are available in the TO-220 package. The TO-220 package is electrically isolated to 2500V rms from the leads to mounting surface. 4000V rms is available on special order. This means that no external isolation is required, thus eliminating the need for separate insulators and insulator-mounting steps and saving dollars over "hot tab" devices. All Teccor triac and diac chips have glass-passivated junctions to ensure long-term device reliability and parameter stability. Variations of devices in this data sheet are available for custom design applications. Consult the factory for more information.