Bridges

AC Wheatstone Bridge

AC Wheatstone Bridge: Impedances at AF or RF are commonly determined by means of an ac Wheatstone bridge. The diagram of an ac bridge is given in Fig. 11.17. This bridge is similar to a dc bridge, except that the bridge arms are impedances. The bridge is excited by an ac source rather than dc …

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Microprocessor Controlled Bridge

Microprocessor Controlled Bridge: Microprocessor Controlled Bridge – Digital computers have been used in conjunction with test systems, bridges, and process controllers for several years. In these applications, computers were used to give instructions and perform operations on the data measured. When microprocessors were first developed they were used in much the same way as digital …

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Detectors Types

Detectors Types: The Detectors Types are as follows For low frequency, the most convenient detector is the vibration galvanometer. For ordinary laboratory work at frequencies up to a few 100 Hz, the moving coil type of instrument is usually employed. It has a high sensitivity. In high voltage testing, the moving magnet type of vibration galvanometer …

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Wagner Ground Connection

Wagner Ground Connection: Wagner Ground Connection – When performing measurements at high frequency, stray capacitances between the various bridge elements and ground, and between the bridge arms themselves, become significant. This introduces an error in the measurement, when small values of capacitance and large values of inductance are measured. An effective method of controlling these …

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Wien Bridge Circuit Diagram

Wien Bridge Circuit Diagram: The Wien Bridge Circuit Diagram shown in Fig. 11.27 has a series RC combination in one arm and a parallel combination in the adjoining arm. Wien’s bridge in its basic form, is designed to measure frequency. It can also be used for the measurement of an unknown capaci­tor with great accuracy. …

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Measurement of Capacitance using Schering Bridge

Measurement of Capacitance using Schering Bridge: A very important bridge used for the precision measurement of capacitors and their insulating properties is the Schering Bridge Experiment. Schering Bridge basic circuit arrangement is given in Fig. 11.25. The standard capacitor C3 is a high quality mica capacitor (low-loss) for general measurements, or an air capacitor (having a …

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Hays Bridge Circuit

Hays Bridge Circuit: Hays Bridge Circuit, shown in Fig. 11.23, differs from Maxwell’s bridge by having a resistance R1 in series with a standard capacitor C1 instead of a parallel. For large phase angles, R1 needs to be low; therefore, this bridge is more convenient for measuring high-Q coils. For Q = 10, the error is …

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Maxwell Bridge Theory

Maxwell Bridge Theory: Maxwell Bridge theory, shown in Fig. 11.21, measures an unknown inductance in terms of a known capacitor. The use of standard arm offers the advantage of compactness and easy shielding. The capacitor is almost a loss-less component. One arm has a resistance R1 in parallel with C1, and hence it is easier …

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Comparison Bridge

Comparison Bridge: There are two types of Comparison Bridge, Namely Capacitance Comparison Bridge Inductance Comparison Bridge 1. Capacitance Comparison Bridge: Figure 11.18 shows the circuit of a capacitance comparison bridge. The ratio arms R1, R2 are resistive. The known standard capacitor C3 is in series with R3. R3 may also include an added variable resistance …

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