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A Silicon Controlled Rectifier (or semiconductor controlled rectifier) is a 4-layer solid state device that controls current flow. The name "silicon controlled rectifier" is a trade name for the type of thyristor commercialized at General Electric in 1957. In physics, the solid state is one of the three phases of matter (solid, liquid, and gas). ...
In electricity, current refers to electric current, which is the flow of electric charge. ...
Cheesy Cheese Cake with strawberries and baked beans with mini sausages in Circuit symbol for a thyristor The thyristor is a solid-state semiconductor device similar to a diode, with an extra control terminal (gate). ...
The General Electric Company, or GE (NYSE: GE) is a multinational technology and services company. ...
1957 (MCMLVII) was a common year starting on Tuesday of the Gregorian calendar. ...
Theory of operation
An SCR can be seen as a conventional rectifier controlled by a gate signal. It is a 4-layered 3-terminal device. A p-type layer acts as anode and an n-type layer as a cathode; the p-type layer closer to the n-type acts as a gate. AC, half-wave and full wave rectified signals A rectifier is an electrical device, comprising one or more semiconductive devices (such as diodes) arranged for converting alternating current to continuous current. ...
A P-type semiconductor is obtained by carrying out a process of doping, that is adding a certain type of atoms to the semiconductor in order to increase the number of free (in this case positive) charges. ...
Diagram of a zinc anode in a Daniells cell. ...
An N-type semiconductor is obtained by carrying out a process of doping, that is adding a certain type of atoms to the semiconductor in order to increase the number of free (in this case negative) charge carriers. ...
Diagram of a copper cathode in a Daniells cell. ...
 An SCR (left) can be thought of as two BJT transistors working together (right). thyristor diagram, created to go with article File links The following pages link to this file: Thyristor Silicon controlled rectifier Categories: GFDL images ...
thyristor diagram, created to go with article File links The following pages link to this file: Thyristor Silicon controlled rectifier Categories: GFDL images ...
The schematic symbols for pnp- and npn-type BJTs. ...
Photo of transistor types (tape measure marked in centimeters) Transistor in the SMD form factor The transistor is a solid state semiconductor device used for amplification and switching. ...
Modes of operation In the normal 'off' state the device restricts current flow to the leakage current. When the gate to source current exceeds a certain point, the device turns 'on' and conducts current. The device will remain in the 'on' state even after gate current is removed so long as current through the device remains above the holding current. Once current falls below the holding current the device will switch off. If the applied voltage increases rapidly, it may induce enough leakage current to trigger the device into the on state, but this is harmful to the device. The reverse blocking voltage is limited in any device. The holding current in a silicon controlled rectifier (SCR) is the minimum current which must pass through the device in order for it to remain in the ON state. ...
Applications SCRs are made with voltage ratings of 50 volts to 2500 volts, and with current ratings up to 3000 amperes per device. SCRs are used in power switching, phase control, chopper, battery chargers, and inverter circuits. Industrially they are applied to produce variable DC voltages for motors (from a few to several thousand HP) from AC line voltage. They can also be used in some electric vehicles to modulate the working voltage in a Jacobson circuit. Another common application is phase control circuits used with inductive loads. SCRs can also be found in welding power supplies where they are used to maintain a constant output current or voltage. Large silicon-controlled rectifer assemblies with many individual devices connected in series are used in high-voltage DC converter stations. A chopper circuit is used to refer to numerous types of electronic switching devices and circuits. ...
Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ...
Electric motors of various sizes. ...
The horsepower (hp) is the name of several non-metric units of power. ...
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
A high output constant current welding power supply for use with GTAW and SMAW A welding power supply is an electrical device that provides an electrical current to perform welding procedures which require electricity. ...
HVDC or high-voltage, direct current electric power transmission systems contrast with the more common alternating-current systems as a means for the bulk transmission of electrical power. ...
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