TRIAC
TRIAC is an example of a semiconductor device with three terminals that can conduct current in both directions is called a TRIAC. It is extensively utilized in AC power control applications, including light dimmer switches, small motor speed control, and appliance heating control.
V-I Characteristics of TRIAC
TRIAC is comprised of two SCRs in backwards equal. It works in four modes. At first the TRIAC works in forward and turn around impeding mode and just little spillage current moves through it. At the point when the applied voltage at the MT2 terminal is additionally expanded and when it crosses the breakover voltage TRIAC begins conduction. The ongoing begin to flow and the voltage applied at the gate terminal controls this current flow.
First Quadrant (I)
- In this quadrant, both MT1 (Main Terminal 1) and MT2 (Mian Terminal 2) are positive concerning the gate terminal.
- At the point when a positive voltage is applied to the gate terminal concerning MT2, the TRIAC becomes forward-one-sided, permitting current to flow.
- The TRIAC conducts during the positive half-cycle of the AC waveform.
Second Quadrant (II)
- MT1 is negative, and MT2 is positive concerning the gate terminal.
- Applying a positive voltage to the gate terminal as for MT1 triggers the TRIAC to lead.
- The gadget conducts during the negative half-cycle of the AC waveform.
Third Quadrant (III)
- Both MT1 and MT2 are negative concerning the gate terminal.
- A negative voltage applied to the entryway terminal as for MT2 makes the TRIAC lead during the positive half-cycle.
- This quadrant permits control of force in the negative half-pattern of the AC waveform.
Fourth Quadrant (IV)
- MT1 is positive, and MT2 is negative concerning the gate terminal.
- A negative voltage applied to the entryway terminal regarding MT1 makes the TRIAC lead during the negative half-cycle.
- This quadrant empowers control of force in the positive half-pattern of the AC waveform.
What is Thyristors in Power Electronics ?
Thyristors in Power Electronics are used as power semiconductor devices which are used as on/off switches in power control circuits. A power semiconductor device is a semiconductor device used as a switch or rectifier in power electronics for example in a switch-mode power supply. A thyristor is the most important type of power semiconductor device. They are extensively used in power electronic circuits. They are operated as bi-stable switches from non-conducting to conducting state. Thyristors are high speed switches that can be used to replace electromechanical relays in many circuits as they have no moving parts, no contact arcing, or suffer from corrosion or dirt. But in addition to simply switching large currents “ON” and “OFF”, thyristors can be made to control the mean value of an AC load current without dissipating large amounts of power.
Table of Content
- What is a Thyristor?
- Properties of Thyristors
- Construction of Thyristor
- Working of Thyristor
- V-I characteristics of thyristor
- Types of Thyristors in Power Electronics
- Examples of Thyristors in Power Electronics