What is the silicon -controlled rectifier?
The residential -controlled silicon rectifier (SCR) is a semiconductor device designed to switch and control high current loads. The SCR is basically a current driver that relies on the externally supplied trigger that turns on. The SCR also contains the preselection of the current values under which they will not be carried out even if they are turned on. This allows control when the device turns on and the minimum current that passes. Osmmetrical silicon -controlled resources are usually used in high -voltage -voltage application, although they often occur in lower voltage systems such as lamp dimers.
SCR consists of four alternating layers of semiconductor materials P and N. The outer line, known as the gate, is connected to the second P layer. The gateway is used to supply the trigger voltage that causes the SCR to turn on and start. The semiconductor wafers consist of a compact pellet contained in the molybdenum or tungsten case. The case is equippedThe end of the end that allows the cooler to connect with the gate and the main input wires located at the other end.
The silicon controller remains inactive or open until the predetermined gateway or trigger pulse is accepted, at this point the device is switched on and allowed to pass through the current. After switching on, the gate voltage can be removed and the SCR will continue to be carried out if the current flow does not drop below the level of the preference. This preset minimum is known as the maintenance current of the device; Although SCR receives a pulse gate, it does not turn on if the main power current is below this level. These properties cause the pro -controlled silicon and the ideal part for carefully controlled current switching.
The rectifier gate voltage is also a variable function during its operation. Each silicon rectifier has a gate voltage with the nominal stattering threshold that the device will not activate. This feature provides a proposalGrounds for further control and flexibility compared to switching conditions of rectifiers. The gate control circuit is often equipped with a protective device known as the Snubber. This prevents a sudden increase in the voltage applied to the rectifier when induced by a capacity bond in the gate and unintentionally on.
SCR is generally used in circuits that have very high current and voltage values. Modern SCRs can conveniently switch power rating exceeding a million watts and have become an integral part of the alternative current with high voltage (AC) to direct current (DC) conversions. These variants with heavy costs are often cooled and suspended in large piles from the ceilings of the energy transfer equipment. SCR can also be found in domestic applications using much lower power levels such as motor controllers, heating controllers and large light dimmers.