Skip to main content


Showing posts with the label Electrical Engineering

Advantages of Stationary Armature

Advantages of Stationary Armature The field twisting of an alternator is p ut on the rotor and is associated with DC supply through two slip rings. The 3-phase armature winding is set on the stator. The advantages of Stationary Armature are the Following. 1.     It is easier to insulate stationary winding for high voltages for which the alternators are usually designed. 2.     It is on the grounds that they are not exposed to diffusive powers and furthermore additional room is accessible because of the stationary course of action of the armature. 3.     The stationary 3-phase armature can be directly connected to load without going through large, unreliable slip rings and brushes. 4.     Only two slip rings are required for DC supply to the field winding on the rotor. Since the exciting current is small, the slip rings and brush gear required are of light construction. 5.     Due to the simple and robust construction of the rotor, the higher speed of rotating DC the field is possible.

Torque Converter - Working, Diagram, Function, Problems

Torque Converter The torque converter is a device used to the multiplication of torque. It consists of: (i) The impeller or the driving member, (ii) The turbine or driven member, (iii) The stator fixed to the frame through a freewheel. Torque Converter Diagram Torque Converter Operation Torque Converter Working  When the engine is started, the impeller starts rotating, the oil from the impeller is pushed into the turbine. The oil, having high kinetic energy from the engine through the impeller hits the outer edge of the turbine. This force will increase with the rise of engine speed. once it's nice enough the turbine starts rotating and therefore the vehicle moves. The fluid from the turbine is made to strike a stator, which changes it’s direction suitably so that the oil leaving g the stator strike the impel [er in a favorable direction i.e. in the same direction in which the impeller is turning. Thus repeated pushing of the turbine blades causes the torque on the turbine to incre

Difference Between Resistance and Impedance

Difference Between Resistance and Impedance Impedance Impedance comprises of two things: reactance and resistance, making the resistance a subset of impedance. Impedance is a progressively broad term for resistance that additionally incorporates reactance. Impedance and reactance are both given in units of 'ohms' simply like resistance. Resistance Resistance is an idea utilized for DC (coordinate flows) while impedance is the AC (exchanging current) identical. Resistance is the restriction of an enduring electric flow. Unadulterated resistance does not change with recurrence, and normally the main time just resistance is considered is with DC (coordinate flow - not evolving) power. Resistance Vs Impedance Resistance is the restriction of the electrical flow stream. Resistance happens in AC and DC circuits. Notwithstanding Resistance, AC circuits additionally show Reactance. Reactance is likewise the restriction to the electrical flow stream. By its very nature,

Tertiary Winding

Tertiary Winding Figure 1(a).shows the circuit diagram for the forward converter with tertiary winding added to the basic configuration. Such converters are used in computers, word processors, televisions, etc. Operation of Tertiary Winding When the transistor Q is turned on, due to the winding polarities, diode Dm is reverse-biased and does not conduct. However, when Q is turned off, Dm is forward-biased and the current flows through the tertiary winding as shown in Fig.1(b).  The residual energy in the transformer core is returned back to the dc source via diode Dm and the tertiary winding. This is how the tertiary winding helps to demagnetize the core and avoids the core saturation.  Due to the dot convention as shown in Fig. 1(a), the primary winding and tertiary winding will never carry current simultaneously. Associated waveforms are shown in Fig. 2. The dark areas on the waveforms of Fig.2 show the magnetizing-demagnetizing current, given as, Tertiary Winding Advantages (i) It n

Semiconductor - Defination, Types

Semiconductor  any of  a category  of solids (such as germanium or silicon) whose electrical conductivity is between that of a conductor  which  of an insulator in being nearly as great as that of a metal at high temperatures and nearly absent at low temperatures A semiconductor is a substance, generally a strong concoction component or aggravate, that can lead power under a few conditions yet not others, making it a decent medium for the control of electrical current. Its conductance changes relying upon the current or voltage connected to a control cathode, or on the power of illumination by infrared (IR), unmistakable light, bright (UV), or X beams.  The particular properties of a semiconductor rely upon the debasements, or dopants, added to it. An N-type semiconductor conveys current for the most part as adversely charged electrons, in a way like the conduction of current in a wire. A P-type semiconductor conveys current dominatingly as electron lacks called gaps. An opening has a

Trapped Charge Effect

Trapped Charge Effect Trapped charges occur on the transmission lines in three-pole out closure operations. The contact-making of three poles of a circuit breaker is non-simultaneous. Consider breakers at the sending end and receiving ends of a line and a transient ground fault, which needs to be cleared by an auto closure operation. The opening of two breakers is nonsimultaneous and the one which opens later must clear two-line phases at no load. These two phrases can, therefore remain charged at the peak of the power frequency voltage, which is still present when the closure takes place. After the dead time, one breaker has to close with two phases still charged. If the closing instant happens to be such that the trapped charge and power frequency voltage are of opposite polarity, maximum transient overvoltage will occur. And these overvoltages will result in the over-current m transmission line.

Negative Booster

Negative booster A negative booster is employed to conform to the regulation that the potential difference between any two points of the rail return shall not exceed 7 V. Two boosters, positive and negative, are used which are mechanically coupled together and driven by a DC motor. The positive booster is connected to the trolley wire (near the generating station) and the negative booster (separately excited) is connected to the track rail.  The 'positive booster' adds voltage to the line while the 'negative booster lowers the potential of the point it is connected to. As we go along the trolley wire away from the generating station/sub-station, the potential drop increases, and the voltage of the trolley wire falls. Since the current returns via the track rail points away from the generating station acquire high potentials. This potential is brought down by the negative boost provided by the negative booster. When the load is sufficiently far aw

Suspension Definition and Properties

Suspension Definition and Properties The substance of little size particles that are insoluble in the solvent, but which are visible distinctly through the naked eye is called a suspension . Thus it is a heterogeneous mixture of two or more substances and in it, the sizes of the dispersed particles are of the order of 10-5 cm or more. The little particles can be filtered and these are temporary which have a common tendency to scatter from the medium of dispersion. There are so many examples of suspension in our common walk of life like the water of the river, smoke in atmospheric air, etc. Properties of Suspension The suspension is a heterogeneous mixture. The particles of suspension can be seen by the naked eye and its size is of the order of 10-5 cm or more. The particles of suspension scatter a beam of light passing through it and make its path transparent (visible). The suspension is unstable because the solute particles settle down when it is left undistributed. That'

SF6 Sulfur Hexafluoride Circuit Breaker

SF6 Sulfur Hexafluoride Circuit Breaker SF6 Circuit Breakers Is a Circuit Breaker whose Excellent insulating, arc-extinguishing, and physical and chemical properties of SF6 gas are the greater advantages of SF6 circuit breakers. The gas is noninflammable and chemically stable. SF6 Circuit Breaker Diagram What is SF6 Gas The gas costs less if manufactured on a large scale.  The gas is transported in liquid form in cylinders. Before filling the gas, the circuit breaker is evacuated  40 the pressure of about 4 mm of mercury so as to remove the moisture and air.  The gas can be reclaimed by the gas handling tank. The sulfur hexafluoride possesses very good insulating properties and outstanding arc-quenching Thametcristics which make it an ideal medium for circuit inscription. The physical, chemical, and dielectric properties and are-quenching characteristics of SF6 gas are given below: It is colorless, odorless, non-toxic, and noninflammable gas. This gas is extremely stable an