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Showing posts from January, 2019

Gunn diode| gunn diode oscillator| gunn diode working|

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Gunn diode This symbol bi-directional but actually this is not bi-directional device.
The Gunn diode is also known asTransferred Electronic Device (TED)because it is composed of N-region, and N-region semiconductor has electrons as a majority carrier, and the Transferred Electronic Devices (TEDs) uses such materials which have electrons in the majority.


Basic information Gunn diodeIt is working on gunn effectIt is not based on P-N junction.It is only based on N-layer.This diode Negative resistance Characteristics.N+ layer highly dopped.It is made GaAs(Gallium arsenide).It is used Microwave applications.Gunn diode Oscillator Gunn diodes are used to build oscillators for generating microwaves with frequencies ranging from 10 GHz to THz. It is a Negative Differential Resistance device – also called as transferred electron device oscillator – which is a tuned circuit consisting of Gunn diode with DC bias voltage applied to it. And, this is termed as biasing the diode into negative resistanc…

what is an auto transfromer in hindi | advantages and disadvantages |

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Auto transformer इस प्रकार के transfomer मे केवल  एक ही winding का प्रयोग किया जाता है |  जो  primary और secondary winding दोनों का कार्य करती है | इस प्रकार का transformer होने के कारण लोहे और ताँबे की बचत की जाती है | auto transformer मे conductor का अनुप्रस्थ काट , उसमे प्रवाहित current के समानुपाती होता है | अतः एक winding मे conductor की लम्बाई वर्तनो ( turns ) की संख्या के गुणनफल के समानुपाती है |

Auto transformer के अनुप्रयोग motor के स्टार्टर के रूप मे 3 फेज system को सन्तुलित रखने मे baster के रूप मे  Auto transformer के लाभauto transformer , copper losses की बचत के लिए प्रयोग किये जाते है | यह regulation transformation के रूप मे उपयोगी है | इन्हे कभी भी booster की भाँति प्रयोग मे लाया जाता है | ताकि A.C feeder की voltage increase की जा सके | auto transformer की high efficiency होती है | इन्हे induction motor को चलने मे auto transformer starter के रूप मे प्रयोग किया जाता है | Auto transformer की हानि इसकी winding जल्द ही ख़राब हो जाती है | अर्थात इनकी उम्र ज्यादा नहीं होती है…

what is an Ideal Transformer in hindi |

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An Ideal Transformer एक Ideal transformer  में किसी प्रकार की हानि नहीं होती है | अथार्त उसकी दोनों winding ( primary winding और secondary winding ) मे कोई ohmic resistance नहीं होता है | 

इस प्रकार के transformer मे  I2R तथा cross losses नहीं होती है |  और न ही magnetic हानि होती है | परन्तु ऐसे transformer  नहीं बनाया जा सकता है |  actual transformer पर load होता है तब उसकी core मे losses होते है | जिन्हे  Iron losses कहते है | तथा transformer की primary और secondary winding मे copper losses को पूर्ण रूप से नगण्य नहीं माना जा सकता है |                                                 इसके विपरीत जब actual transformer पर कोई load नहीं होता है तो भी primary और secondary winding मे losses होते है |

what is the name of transformer oil ? Can transformer oil be used for cooking?

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properties of transformer oil, electrical, physical and chemical property of transformer oil
Insulating oil/ mineral insulating oil.obtained by fractional distillation and subsequent treatment of crude petroleumTransformer oil dissipates heat of the transformer e.i. acts as a coolant and prevents direct contact of atmospheric oxygen with cellulose made paper insulation of windings, which is susceptible to oxidation.

Types of Transformer Oil

1. Paraffin based transformer oil 2. Naphtha based transformer oil
Paraffin based transformer oil
lower oxidation rate than that of Naphtha oil. insoluble oxidation product or sludge obstruct the transformer cooling system. easy availability high pour point due to the wax content use due to warm climate condition of India.

Naphtha based transformer oil
easily oxidized than Paraffin oil. soluble oxidation product, i.e. sludge does not disturb the transformer cooling system

Parameters of Transformer Oil Electrical parameters :– Dielectric strength…

Op Amp Basic | What is an operational amplifier | operational amplifier characteristics |

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Operational Amplifier ( op- Amp)op- Amp amplifier is a linear integrated circuit. Operational amplifier is three terminal devices. two input terminal (inverting terminal and non inverting terminal) and one output terminal . negative terminal also called inverting terminal and positive terminal called Non- inverting terminal.

the typical operational amplifier is a high gain D.C amplifier usable from 0 TO OVER 1 MHZ. By connecting external resistor voltage gain and bandwidth can be adjusted as per requirements.it is suitable for D.C as well as A.C applications.the complete operational amplifier circuit, which may consists of 32 transistors and numerous resistors  along with a few semiconductor diodes is fabricated in a space of about 100 mm or so. this renders the electronic circuitry the compactness along with reliability and longer life.operational amplifier always work negative feed back.  Operational amplifier Characteristics ;
an ideal case op- ampRi ( Input resistance)               …

what is the thermistors , themistors use and applications |

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THERMISTOR


Thermistors baiscally Semi-conductor device. These transducer are thermally sensitive variable resistors made of certain conducting and ceramic- like semiconducting materials. They are used as temperature detecting elements and sense temperature detecting elements and sense temperature for the purpose of measurement and control.    Thermistors  are essentially semiconductors which behave as resistors with a high negative temperature co-efficient of resistance. The high sensitivity to temperature changes make the thermistors extremely useful for precision temperature (-60 C to + 15 C ) measurements , control and compensation. Their resistance ranges from 0.5 ohm to 0.74 M ohm.                          Thermistors are composed of sintered mixtures of metallic oxides such as manganese, nickle, cobalt, copper, iron and uranium. fig. shows the commercial forms of thermistors.Applicationsprecision temperature measurement.temperature control.

What are Piezoelectric Transducers? What is Piezoelectric Effect? working

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PIEZOELECTRIC TRANSDUCER What is Piezo-electric effect? A piezo-electric material is one in which an electric potential appears across certain surface of a crystals if the dimensions of the crystal are changed by the application of a mechanical force. this potential is produced by the displacement of external charges. The effect is reversible,i.e., conversely, if a varying potential is applied thereby deforming it. This effect is know as piezo-electric effect









Elements exhibiting piezo-electric qualities are sometimes known as electro-resistive elements .Common piezo-electic materials are: ammonium dihydrogen phosphate, Rochelle salts, lithium sulphate , dipotassium tartarte , potassium dihydrogen phosphate, quartz and ceramics A and B. there are two main group of piezo- electric crystals ; 1. natural crystals....... such as quartz and tourmaline. 2. Synthetic crystals..... such as rochelle salt, lithium sulphate, dipotassium tartrate etc. Working A typical mode of operation of piezo-…