Variable Frequency Control of Multiple Synchronous Motors: A drive operating in true Variable Frequency Control of Multiple Synchronous Motors is shown in Fig. 7.9. Frequency command f* is applied to a voltage source inverter through…
Variable Frequency Control of Induction Motor Drive: Variable Frequency Control of Induction Motor Drive - Synchronous speed, therefore, the motor speed can be controlled by varying supply frequency. Voltage induced in stator is proportional to…
Variable Frequency Control From Current Source: Control of induction motor employing variable frequency voltage sources was considered in previous section. This section considers motor control by Variable Frequency Control From Current Source (VFCS). An equivalent…
Varactor Diode Symbol: A specially processed junction diode that assumes the properties of a variable capacitor (about 5 - 250 pf) when its dc reverse voltage is varied is called a Varactor Diode shown in…
Varactor Diode Operation and Characteristics: Varactor Diode Operation and Characteristics were first used in the early 1950s as simple voltage-variable capacitance and later for frequency modulation of oscillators. They thus represent a very mature semiconductor…
Vapour Phase Epitaxy Process: In chemical vapour deposition (CVD), the film is formed on the surface of the substrate by thermal decomposition and or the reaction of various gaseous compounds. As in CVD, the epitaxial…
Van De Graaff Generator Working Principle: The schematic diagram of a Van De Graaff Generator Working Principle is shown in Fig. 6.6. The generator is usually enclosed in an earthed metallic cylindrical vessel and is…
Vacuum Triode, Construction and Working: Construction of Vacuum Triode - The construction and the schematic symbol used for a vacuum triode are illustrated in Fig. 5.8. It, as the name suggests, consists of three electrodes…
Vacuum Insulation: The idea of using Vacuum Insulation purposes is very old. According to the Townsend theory, the growth of current in a gap depends on the drift of the charged particles. In the absence…
Vacuum Circuit Breaker: Although the advantages of interrupting the arc in a vacuum were recognized as early as the nineteenth century, this did not find wide application till a few years ago. This was because…
