Table of Contents
Does bridge depend on frequency?
Wien bridges are useful for determining the values of “lossy” capacitor designs like electrolytics, where the internal resistance is relatively high. They are also used as frequency meters because the balance of the bridge is frequency-dependent.
Which bridge is frequency sensitive?
Important Points
Type of Bridge | Name of Bridge | Important |
---|---|---|
AC Bridges | Campbell’s modification of Heaviside bridge | |
De-Sauty’s bridge | Suitable for perfect capacitor | |
Schering bridge | Used to measure relative permittivity | |
Wein’s bridge | Harmonic distortion analyzer, used as a notch filter, used in audio and high-frequency applications |
Which AC bridge is used to determine the frequency of the source?
4.6
Type of Bridge | Name of Bridge | Important |
---|---|---|
DC Bridges | Kelvin double bridge | |
Loss of charge method | ||
Megger | Resistance of cables | |
AC Bridges | Maxwell’s inductance bridge | Not suitable to measure Q |
What are the two conditions of balance in AC Bridge?
AC Bridges general balance equation The current through detector must be 0 that requires the potential difference Vbd to be 0. In such a condition voltage drop from a to b will get equal to voltage drop from a to d, both in magnitude and phase.
Which type of detector is used in AC bridges?
Explanation: Vibration galvanometers are used as detectors in AC bridges for low audio frequency.
Which of the following bridge is not a type of AC bridge?
Which of the following is not an AC bridge? Explanation: Kelvin Bridge is a DC bridge used for measuring resistance. 4.
What are the other AC bridges to measure the frequency of unknown signals?
Wien’s Bridge The AC detector and AC voltage source are also required in order to find the value of frequency. Hence, one of these two are placed in one diagonal of Wien’s bridge and the other one is placed in other diagonal of Wien’s bridge.
Why AC bridges are used in impedance measurement?
The D.C bridges are used to measure the resistance while the A.C bridges are used to measure the impedances consisting capacitance and inductances. The D.C bridges use the D.C voltages as the excitation voltage while the A.C bridges use the alternating voltage as the excitation voltage.
What are the types of detectors used in AC bridges?
Commonly used balance detectors for AC bridges are headphones, tuned amplifiers and vibration galvanometers. Explanation: Headphones, tuned amplifier circuits and vibration galvanometers are used for detecting the balance condition in AC bridges.
Why galvanometer is not used in AC bridge?
In AC bridge galvanometer is not used because the rotating torque is dependent on the average current that is passing through the coils of a galvanometer. Also, the average AC current passing through the AC bridge will be zero and there will not be any deflection.
What is an AC bridge?
AC bridges operate with only AC voltage signal. The circuit diagram of AC bridge is shown in below figure. As shown in above figure, AC bridge mainly consists of four arms, which are connected in rhombus or square shape. All these arms consist of some impedance.
What are the alternating current bridge methods?
Alternating current bridge methods are important for measurement of inductance, capacitance, storage factor, dissipation factor etc.The a.c. bridge is natural out growth of Wheatstone Bridge.It’s basic form consist of four arms, a source of excitation (ac source), a balance detector.
What is the general form of the AC impedance bridge?
Generalized AC impedance bridge: Z = nonspecific complex impedance. For this general form of the AC bridge to balance, the impedance ratios of each branch must be equal: Again, it must be stressed that the impedance quantities in the above equation must be complex, accounting for both magnitude and phase angle.
What is a potential problem in an AC bridge circuit?
A potential problem in sensitive AC bridge circuits is that of stray capacitance between either end of the null detector unit and ground (earth) potential. Because capacitances can “conduct” alternating current by charging and discharging, they form stray current paths to the AC voltage source which may affect bridge balance: