Search results
Results from the WOW.Com Content Network
A thyristor (/ θ aɪ ˈ r ɪ s t ər /, from a combination of Greek language θύρα, meaning "door" or "valve", and transistor [1]) is a solid-state semiconductor device which can be thought of as being a highly robust and switchable diode, allowing the passage of current in one direction but not the other, often under control of a gate electrode, that is used in high power applications ...
The term thyristor includes all the semiconductor devices, which show inherent ON-OFF behavior, as opposed to allowing gradual changes in conduction. All thyristors are regenerative switching devices, and they cannot operate in linear manner. Thus, a transistor is not a thyristor even though it can operate like a switch (ON-OFF). The transistor ...
In this operating mode, the controller changes the phase angle α of the thyristor ignition timing. A half wave corresponds to 180 ° el. (electrical degree). The actuator can adjust the phase angle of 0 ° el. (maximum power) up to 180 ° el. (no power). In a 50 Hz mains the controller switches every 20 ms and shows very fast behavior.
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 ...
A motor controller is a device or group of devices that can coordinate in a predetermined manner the performance of an electric motor. [1] A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque, and protecting against overloads and electrical ...
SCR 4-layer (p-n-p-n) diagram. A silicon controlled rectifier or semiconductor controlled rectifier (SCR) 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 current in the TCR is varied from maximum (determined by the connection voltage and the inductance of the reactor) to almost zero by varying the "Firing Delay Angle", α. α is defined as the delay angle from the point at which the voltage becomes positive to the point at which the thyristor valve is turned on and current starts to flow.
Phase-fired control (PFC), also called phase cutting or phase-angle control, is a method for power limiting, applied to AC voltages. [1] It works by modulating a thyristor , SCR , triac , thyratron , or other such gated diode -like devices into and out of conduction at a predetermined phase angle of the applied waveform.