Electrical4U 
The Physics of a Semiconductor There are some materials, which have neither good conductivity nor bad conductivity of electricity. They have a moderate range of electrical conductivity. The examples of such materials are germanium, silicon, carbon etc. As the conductivity of those materials lies between good conductors and insulators, and these materials are called semiconductors. … Read more
DC-DC converters are also known as Choppers. A Step Up Chopper or Boost converter raises the input DC voltage to a higher specified DC output voltage. A typical Boost converter is shown below. The input voltage source connects to an inductor. A solid-state switch is connected across the source. Another switch, a diode, connects to … Read more
Power electronics focuses on converting power from one form to another and changing voltage levels using power electronic converters. The four families are DC to DC, AC to DC, DC to AC and AC to AC. Control and signal conditioning sit around those converters. The conditioning of signals is the attempt to keep input and … Read more
Electrostatic precipitators in thermal power plants have a known set of advantages and disadvantages. An electrostatic precipitator uses a high-intensity electric field to ionize dust particles in the air, which are then collected by oppositely charged collectors (electrodes). These dust particles are periodically removed from the collector plates by rapping or by washing on wet … Read more
The efficiency of Electrostatic precipitators in a thermal power plant or other power plants is the fraction of inlet dust mass collected. It depends on corona power, dust resistivity, particle size and the Deutsch-Anderson terms w, A and Q. Plants set a design efficiency from the emission limit; it is not one worldwide legal number. … Read more
There are different types of synchronous motors based on how the rotor field is produced. The two groups are non-excited rotors and current-excited rotors. Non-excited machines use steel, hysteresis material or permanent magnets. Current-excited machines use a DC field winding on the rotor. Non Excited Synchronous Motor The rotor in non-excited synchronous motors is steel … Read more
Introduction of Indoor Switchgear Switchgear is a generalized term given to a unit which is a combination of protective control and metering types of equipment as a whole. Switchgear can be of different forms depending on the kind of applications such as protection of feeders, protection of motors, rail traction purposes, measurements etc. For example, … Read more
DC-DC converters, often called Choppers, include the Buck converter, which steps down a higher input DC voltage to a lower specified output voltage. In continuous conduction the ideal relation is Vo = D Vin, where D is the switch duty cycle.A typical Buck converter is shown below. The input vvoltage source connects to a controllable … Read more
The characteristics of a Zener diode are its forward and reverse current-voltage curves, especially the reverse knee. Ordinary diodes mainly conduct when forward biased, with a small voltage drop. In reverse they pass only a tiny current until breakdown voltage. Uncontrolled breakdown can destroy a rectifier. The Zener diode is rated to run in reverse … Read more
The main components of Electrostatic precipitators in thermal power plants and other power plants are discharge electrodes, collecting plates, a transformer-rectifier, rappers, hoppers and insulators. They use a high-intensity electric field to ionize dust in the flue-gas stream. Opposite plates collect the charged dust. Rapping or washing then drops it into the hopper. The components … Read more