Dnyanesh

  • Magnetizing current in an Induction motor is the current drawn to set up the necessary rotating magnetic field.  This magnetizing current only experiences an inductive reactance due to the winding (as winding will act like an inductor). And as we know, current lags behind voltage for an inductive reactance, this causes lagging power factor. That…[Read more]

  • You may simply install some transformer cooling fans on the radiators of the transformer as illustrated in the figure below.

    air cooling of distribution transformer

    For different types of cooling methods of transformers, check out the following link :http://www.electricaleasy.com/2014/06/cooling-methods-of-transformer.html

  • I’m sorry that I did not get your question clearly. You may find what you are looking for at the Matlab’s official website at the following link : https://in.mathworks.com/help/physmod/sps/powersys/ref/permanentmagnetsynchronousmachine.html#f3-2399515

  • Kiran Daware replied to the topic Exciter in the forum Common electrical queries 7 months ago

    What do you actually mean by exciter? Do you mean exciter used in an AC generator (alternator)?

    In an alternator, the field current is supplied by an exciter which is mounted on the same shaft. Generally, small DC shunt generators are used for exciting the field winding of an alternator. Nowadays, modern alternators use static exciters.

  • In the Short circuit test of a synchronous machine, the armature terminals are short-circuited through ammeters. Then the machine is rotated at rated speed while gradually increasing the field current.

    So, in case of short-circuiting, V=0 and hence the rate of change of total flux must also be zero. So the short-circuit current have to rise only…[Read more]

  • Consider the center tapping point as O,  the upper terminal as A and the lower terminal as B. Now, in a center tapped transformer Voa is 180 degrees out of phase with Vob. But, the Vao and Vob are in phase with each other. So, the voltage between terminals A and B is additive.

    Learn in more details at the following link, where you will…[Read more]

  • In a practical circuit, use digital meters like multimeter, ammeter and/or voltmeter to find currents and voltages.

    If you are going to calculate these values using a program, you may use standard formulae. You can find these standard formulae online or in a reference book easily. Some of the standard formulae are as following –

    Voltage =…[Read more]

  • SCR, DIAC, TRIAC & MOSFET
    Thyristor or SCR – Silicon Controlled Rectifier
    An SCR is basically a Shockley diode with just an added Gate terminal. Hence, an SCR is a three terminal device with 4 layers – PNPN. An SCR has three PN junctions J1, J2 and J3. The three terminals of an SCR are – Anode which is connected to P type layer, Cathode con…[Read more]

  • SCR, DIAC, TRIAC & MOSFET
    Thyristor or SCR – Silicon Controlled Rectifier
    An SCR is basically a Shockley diode with just an added Gate terminal. Hence, an SCR is a three terminal device with 4 layers – PNPN. An SCR has three PN junctions J1, J2 and J3. The three terminals of an SCR are – Anode which is connected to P type layer, Cathode con…[Read more]

  • Vicky and Profile picture of DnyaneshDnyanesh are now friends 9 months, 4 weeks ago

  • Vicky and Profile picture of Kiran DawareKiran Daware are now friends 10 months ago

  • Sir please tell me difference in principle of scr , diac , traic , mosfet

    And their application

  • Vicky became a registered member 10 months ago

  • An Inductor is basically just a wound conductor to form a coil. Inductance is a property of conductor due to which an electromotive force is induced by varying current flowing through the conductor. EMF gets induced due to varying current in itself (self-inductance) and also in conductors that are in close proximity (mutual inductance).

    So, when…[Read more]

  • Thank you… 🙂

  • How are you supposed to start an induction motor with a DC supply? For working of an induction motor, production of Rotating Magnetic Field in the field winding is necessary. This rotating magnetic field is produced due to alternating flux. Only an AC supply produces alternating flux, DC supply would only provide unidirectional flux. So, an…[Read more]

  • If the generator output is zero even when the armature is running, the possible cause could be in the armature or field winding. If you the field voltage is absent, what kind of generator it is, a self-excited or separately excited? If it is self-excited, dismantle the generator and check out its field winding, whether it has been burnt out or…[Read more]

  • Inductor blocks ac and allows dc.  Then how does this inductor works with ac circuit?  Take an example of a tube light circuit.

  • Can we start single phase/three phase induction machine with dc supply?  What will happen if we give dc supply to induction motor?

  • Multiple Choice questions on single-phase induction motors. Each question will have four options of which only one is correct. Take this objective questions quiz to test your knowledge of induction motors.

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