Solid State Voltmeter: Solid State Voltmeter - Figure 4.13 shows the circuit of an electronic voltmeter using an IC OpAmp 741C. This is a directly coupled very high gain amplifier. The gain of the OpAmp…
Chopper type DC Amplifier Voltmeter (Microvoltmeter): Chopper type DC Amplifier Voltmeter the dc input voltage is converted into an ac voltage, amplified by an ac amplifier and then converted back into a dc voltage proportional…
Transistor Voltmeter (TVM): Transistor Voltmeter - Direct coupled amplifiers are economical and hence used widely in general purpose low priced VTVM' s. Figure 4.9 gives a simplified schematic diagram of a dc coupled amplifier with…
DC Meter: The most commonly used dc meter is based on the fundamental principle of the motor. The motor action is produced by the flow of a small amount of current through a moving coil…
Measurements of very Large Currents by Thermocouples: Measurements of very Large Currents by Thermocouples - Thermocouples instruments with heaters large enough to carry very large currents may have an excessive skin effect. Ordinary shunts cannot…
Various Factors of Frequency Effect on Calibration: The Various Factors of Frequency Effect on Calibration such as: Skin effect Non uniform distribution of current along the heater wires Spurious capacitive currents 1. Skin Effect: The…
Thermocouple Principle and Types of Thermocouple: Thermocouple Principle consists of a junction of two dissimilar wires, so chosen that a voltage is generated by heating the junction. The output of a thermocouple is delivered to…
DC Ammeter: DC Ammeter - The PMMC galvanometer constitutes the basic movement of a dc ammeter. Since the coil winding of a basic movement is small and light, it can carry only very small currents.…
Classification of Printers: Classification of Printers - Character printers and graphic plotters are the two devices used to prepare a permanent (or hard copy) record of computer output. The basic difference between printers and plotters…
Structure of Liquid Vapour Display (LVD): Liquid Vapour Display (LVD) are the latest in economical display technology. They employ a new reflective passive display principle and depend on the presence of ambient lights for their…
