Deepakkumar Yadav
Static (I-V) Characteristics of MOS Controller Thyristor (MCT) In the static condition, the I-V characteristics of the MCT are similar to those of SCR and GTO. Switching Characteristics of MOS Controller Thyristor (MCT) MCT can change its state from ON to OFF or OFF to ON within 1 µsec. Figure (a) shows a switching circuit using … Read more
MOS Controlled Thyristor Precaution MCT works as a gate controlled device if its current is less than a value called peak controllable current. If we try to turn off the MCT when current through it is higher than its rated peak controllable current, then the MCT may get destroyed. Hence for higher values of currents, … Read more
TESTING AND QUALITY ASSURANCE (QA) DURING MANUFACTURE Unlike many items of electrical power plant (for example, switchgear and motors) most transformers are still virtually handmade, little or no mass production is employed in manufacture and each is produced very much as a one-off. This means that the user cannot rely on extensive type testing of … Read more
Godown Wiring Connection This type of lighting system is used in the tunnel-like structure. Where a person can go very deep or long but also want to save on electricity consumption, like in big godowns, long passages, warehouses and tunnel-like structures having many rooms or portions. It follows the linear sequence for switching the lights … Read more
MOS Controlled Thyristor (MCT) Construction of MOS Controlled Thyristor (MCT) MCT is a special device which has the characteristics of a four layer p-n-p-n SCR and a MOS – gate structure. The schematic diagram of an MCT is shown in Figure (a). Its equivalent circuit is shown in Figure (b) and circuit symbol in Figure … Read more
Operation of Static Induction Thyristors (SIT) Anode is connected to a positive voltage with respect to cathode and a positive voltage pulse is applied to the gates Figure (a). Figure (a) The depletion region is filled with carriers and the device is turned ON. The anode current flows from anode to cathode. Now refer Figure … Read more
Important characteristics of SIT (Static Induction Thyristor) Symbol of SIT Switching speed : 1 to 6 µS Voltage rating : upto 2500 V Current rating : only upto 500 A The biggest disadvantage of SIT is that it is extremely sensitive to the perturbations in the manufacturing process. Small variations in the manufacturing process can … Read more
For protection of transformer against to overcurrent which protection is provided To protect transformer we mostly proved protection against overcurrent, overvoltage, undervoltage and under frequency. In that most important is Overcurrent protection, we use Circuit Breaker for protection of transformer. Types of Circuit breaker use for protection of Transformer 1. Air Circuit Breaker (ACB) 2. … Read more
Static Induction Thyristors (SIT) Construction and output characteristics A SIT or SI-thyristor, is a self controlled GTO like ON-OFF device. It is a three terminal device. The three terminals are Anode, Cathode and Gate. The characteristics of SIT are very similar to those of a power MOSFET. It is turned on by applying a positive … Read more
Transformer Rated power (KVA) Impedance % Up to 630 4 % 631 to 1 250 5 % 1 251 to 2 5oo 6 % 2 501 to 6 300 7 % 6 301 to 25 000 8 % 25 001 to 40 000 9 % 40 001 to 63 000 10 % 63 001 to … Read more