Electrical and Electronics

What is GTO? GTO is a three terminal device with anode, cathode and gate. It is similar to SCR. The major difference between SCR and GTO is that GTO can be turned off . GTO is a PNPN device that can be turned on by applying positive gate pulse and turned off   by applying negative gate pulse. So, it is called as non-latching device . It has higher switching speed than SCR and it can withstand higher voltage and current. At present, GTO with ratings up to 5000 V and 3000 A are present.  The GTO switches regeneratively into the on-state when a positive gate signal is applied to base of NPN transistor. During turn-off, the internal regeneration is reduced by reducing the current gain  of the PNP transistor which draws sufficient current from the gate. The reduction in gain of NPN transistor can be achieved by, Gold doped GTO Anode-shorted GTO   Gold doped GTO                        Anode-shorted GTO   ...

What is Thyristor? The term Thyristor came from its gas tube equivalent, thyratron. Its family name includes, Silicon Controlled Rectifiers(SCR) Bidirectional Triode Thyristors(TRIAC) Gate Turn-off Thyristors(GTO) MOS Controlled Thyristors(MCT) Integrated Gate-Commutated Thyristors(IGCT) Thyristors are operated as bi-stable switches, operating from non conducting state to conducting state. Thyristor can recover from its conducting state to non conducting state only when the current is brought to zero. It has four or more layers and three or more junctions. This device blocks voltage in both forward and reverse direction. The SCR is almost referred to as thyristor.   Thyristor(SCR) Characteristics SCR is a four-layer semiconductor device of PNPN structure with three p-n junctions. It has three terminals namely, anode, cathode and gate. The cross section of thyristor can be split into sections of NPN and PNP transistors.  When the anode voltage is made positive with respect...