Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

Definition of LVDTThe term LVDT stands for the Linear Variable Differential Transformer. It is the most widely used inductive transducer that converts the linear motion into the electrical signal.The output across secondary of this transformer is the differential thus it is called so. It is very accurate inductive transducer as compared to other inductive transducers.Construction of LVDTMain Features of Construction The transformer consists of a primary winding P and two secondary windings S1and

What is Piezoelectric TransducerA piezoelectric transducer (also known as a piezoelectric sensor) is a device that uses the piezoelectric effect to measure changes in acceleration, pressure, strain, temperature or force by converting this energy into an electrical charge.A transducer can be anything that converts one form of energy to another. The piezoelectric material is one kind of transducers. When we squeeze this piezoelectric material or apply any force or pressure, the transducer converts

Principle of Tan Delta TestA pure insulator when is connected across line and earth, it behaves as a capacitor. In an ideal insulator, as the insulating material which acts as dielectric too, is 100 % pure, the electric current passing through the insulator, only have capacitive component. There is no resistive component of the current, flowing from line to earth through insulator as in ideal insulating material, there is zero percent impurity.In a pure capacitor, the capacitive electric current

Polarization Index Test (PI Value Test) along with Insulation Resistance Test (IR Value Test) is conducted on HV electrical machine to determine service condition of the insulation. IP test is conducted especially to determine the dryness and cleanliness of the insulation.In insulation resistance test, a high DC voltage is applied across the insulator. This applied voltage is then divided by current through the electrical insulator to obtain resistive value of the insulator. Since, as per Ohm’s

What is a Transducer?An electrical transducer is a device which is capable of converting physical quanties into a proportional electrical quantity such as voltage or electric current. Hence it converts any quantity to be measured into a usable electrical signal. This physical quantity which is to be measured can be pressure, level, temperature, displacement etc. The output which is obtained from the transducer is in the electrical form and is equivalent to the measured quantity. For example, a t

A potentiometer is an instrument which measures unknown voltage by balancing it with a known voltage. The known source may be DC or AC. The working phenomenon of DC potentiometer and AC potentiometer is same. But there is one major difference between their measurements, DC potentiometer only measures the magnitude of the unknown voltage. Whereas an AC potentiometer measures both the magnitude and phase of unknown voltage by comparing it with a known reference. There are two types of AC potentiom

What is a Potentiometer?Apotentiometer(also known as apotorpotmeter) is defined as a 3 terminalvariable resistorin which theresistanceis manually varied to control the flow ofelectric current. A potentiometer acts as an adjustablevoltage divider.How Does a Potentiometer Work?A potentiometer is a passive electronic component. Potentiometers work by varying the position of a sliding contact across a uniform resistance. In a potentiometer, the entire input voltage is applied across the whole length

Various methods are used for measurement of three phase power in three phase circuits on the basis of number of wattmeters used. We have three methods to discuss: Three wattmeters method Two wattmeters method Single wattmeter method.Let us discuss one by one each method in detail.Measurement of Three Phase Power by Three Wattmeters MethodThe circuit diagram is shown below-Here, it is applied to three phase four wire systems, current coil of all the three wattmeters marked as 1, 2 and 3 are conne

Before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter. Dynamometer type wattmeter works on very simple principle and this principle can be stated as when any current carrying conductor is placed inside a magnetic field, it experiences a mechanical force and due to this mechanical force deflection of conductor takes place.Construction and Working Principle of Electrodynamometer Type Wattme

What is a Low Power Factor Wattmeter?A low power factor meter is an instrument that is used to accurately measure low values of power factor. Before we study more about the low power factor meter, we need to understand why we need a low power factor wattmeter in the first place (as opposed to a standard electrodynamometer wattmeter)The answer is simple: a standard wattmeter gives inaccurate results.Now there are two main situations where we should not use an ordinary wattmeter in measuring a low