Measurement of resistance

Measurement of resistance- Properties of resistance plays an important role in determining performance specification for various circuit elements including coil, winding, insulation etc. Apart from this resistor are use as standard for measurement of other unknown resistances and for the determination of unknown inductance and capacitance. For the point of view measurement of resistance are classified into three… Read More »

Different methods of measurement

Different methods of measurement- There are two methods of measurement- 1. Direct measurement method 2. Indirect measurement method Direct measurement method- Direct comparison with standard In this method of measurement, we compare the quantity with primary standard or secondary standard. Ex- If we have to measure the length of a bar, we measure it with the help of… Read More »

JFET as an amplifier

JFET as an amplifier- The weak signal is applied between gate and source, and amplified output is obtained across drain and source terminal. For proper operation of JFET gate must be negative with respect to source. Input circuit should always be reversed biased with help of a battery Vgg or by a circuit is known as biasing circuit.… Read More »

Working of JFET

Working of JFET- The two P-N junctions at the sides form two depletion layers. The current conduction by charge carrier i.e. electrons in case of N-channel JFET is thought the channel between two depletion layers and out of drain. The width and hence resistance of this channel can be control by changing the input voltage Vgs. The greater… Read More »

Preventive maintenance planning

It is mostly used in maintenance department. The maintenance engineer inspects the plant periodically under working condition and when it is rest, with good planning and preparation. The planning of maintenance is categorized in following ways- Routine maintenance Periodically maintenance Maintenance of fault when fault occurs Routine maintenance- It should be carried out daily. It includes visual inspection,… Read More »

Necessity of relay for electrical motor

A relay is a device that opens or closes an auxiliary contact under some predetermined condition in the main circuit. It also provides complete electrical isolation between the control circuit and power circuits. Main parts of relay are armature contacts and coil. it has normally open (NO) contact which can be closed by action of relay. It has… Read More »