Search results
Results from the WOW.Com Content Network
TRIAC. For other uses, see Triac. A TRIAC (triode for alternating current; also bidirectional triode thyristor or bilateral triode thyristor[ 1 ]) is a three-terminal electronic component that conducts current in either direction when triggered. The term TRIAC is a genericised trademark. TRIACs are a subset of thyristors (analogous to a relay ...
The thyristor is a four-layered, three-terminal semiconductor device, with each layer consisting of alternating N-type or P-type material, for example P-N-P-N. The main terminals, labelled anode and cathode, are across all four layers. The control terminal, called the gate, is attached to p-type material near the cathode.
A silicon controlled rectifier or semiconductor controlled rectifier is a four-layer solid-state current -controlling device. The name "silicon controlled rectifier" is General Electric 's trade name for a type of thyristor. The principle of four-layer p–n–p–n switching was developed by Moll, Tanenbaum, Goldey, and Holonyak of Bell ...
Like an SCR, when a voltage pulse is present on the gate terminal, the device turns on. The main difference between an SCR and a Triac is that both the positive and negative cycle can be turned on independently of each other, using a positive or negative gate pulse. Similar to an SCR, once the device is turned on, the device cannot be turned off.
A Voltage controller thyristor based dimmer rack An electrical schematic for a typical SCR-based light dimmer. A voltage controller, also called an AC voltage controller or AC regulator is an electronic module based on either thyristors, triodes for alternating current, silicon-controlled rectifiers or insulated-gate bipolar transistors, which converts a fixed voltage, fixed frequency ...
The control signal must be coupled to the controlled circuit in a way which provides galvanic isolation between the two circuits. Many SSRs use optical coupling. The control voltage energizes an internal LED which illuminates and switches on a photo-sensitive diode (photo-voltaic); the diode current turns on a back-to-back thyristor ( TRIAC ...
A crowbar circuit is an electrical circuit used for preventing an overvoltage or surge condition of a power supply unit from damaging the circuits attached to the power supply. It operates by putting a short circuit or low resistance path across the voltage output (V o), like dropping a crowbar across the output terminals of the power supply.
Antiparallel (electronics) In electronics, two anti-parallel or inverse-parallel devices are connected in parallel but with their polarities reversed. One example is the TRIAC, which is comparable to two thyristors connected back-to-back (in other words, reverse parallel), but on a single piece of silicon. Two LEDs can be paired this way, so ...