cosmos

Most of the IGBT available in the market having the buffer layer in them. IGBT having the buffer layer in them are called Asymmetric IGBT(Punch-trough IGBT). Because of the presence of the n+ buffer layer in the IGBT, it unable to block the large reverse voltage, therefore the device breakdown at the lower reverse voltage. This offers the IGBT  the fast switching time, as compare the symmetric configuration.

Static switch 1) Static switches use semiconductor elements such as SCR to perform the shifting of load between two power sources. 2)Circuit offers very fast switching time, usually in the range of the milliseconds. This help to maintain the uninterrupted power supply to the load. 3) The static switch consists of three parts:     a) Breaker.    b) SCR.    c)  Control system. 4) current sensing device constantly monitors the output of the switch and provide the necessary input to the control relay circuit. 5)If the AC source fails to supply the voltage to the load, the control circuit switches connection to the inverter input source. Block Diagram of the static switch is as follows: Application of the static switch: 1) The static switch is used in the UPS system. 

ANTENNAS: TYPE OF ANTENNAS Definition:   An antenna is a structure that is generally metallic object, often a wire or group of wire used to convert the high-frequency current into electromagnetic waves, and vice-versa Type of antennas: 1) Omni-directional antennas:  Omni-directional antennas propagate the radio wave signal in all horizontal directions.  Dipole antennas: This is the type of the omnidirectional antenna whose propagating radio frequency (RF) energy in 360 degrees in the horizontal plane. This antenna can be as simple as two pieces of wire cut to the proper length or can be encapsulated. An antenna exhibits a typical impedance, allowing antenna of the transmitter for maximum power transfer. Majority of the wireless access points and routers have these wireless antennas due to their reliable performance and uniform coverage. Example of omnidirectional antennas is   Rubber duck Omni Directional Antenna 2) S emi-direction...