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A bridge circuit works at a frequency of 3 kHz. Which detector can be used for detecting the null conditions in the bridge?
For 3 kHz frequency headphone (Range - 250 Hz to 4 kHz) and tuned amplifier detector (Range - 10 Hz to 100 kHz) will be used.
Inductance comparison bridge uses
The equations under conditions of balance for a bridge measuring resistance R1, and inductance L1 of a choke coil are
In order to achieve convergence of balance
The bridge circuit for the given balance condition indicates that of a Maxwell’s inductance capacitance bridge as shown below.
For sliding balance, R4 and C4 will be varied since they are not common in the equations of R1, and L1.
in order to achieve convergence to balance point, R4 and C4 will be varied since they are in the same arm of the bridge.
In measurement of resistance by “Carey Foster bridge” no error is introduced due to
“Carey Foster slide wire bridge” is a special type of bridge circuit which is used for the measurement of medium resistance by comparing with a standard known resistance. This bridge circuit will give no error due to connecting lead resistances, thermoelectric emfs and contact resistances.
A capacitance comparison bridge as shown in figure below is used to measure a capacitive impedance at a frequency of 2 kHz. The bridge constants at balance are:
The equivalent series circuit of the unknown impedance will be represented as:
At balance condition,
Separating real and imaginary parts, we have:
A Wien bridge circuit consists of the following:
The frequency of the circuit is
The frequency measured by the Wien bridge is:
An ac bridge uses a detector in the form of
Maxwell’s bridge is used to measure Q-factor in the range
Maxwell’s bridge is used to measure Q-factor of medium Q-coils i.e. 1 < Q < 10
Anderson bridge is used to measure unknown
Anderson bridge is used for the measurement of low Q -coils i.e. measurement of low inductance.
Hay’s bridge is used to measure an inductance of
Hay’s bridge is used for the measurement of inductance of high Q-coils (Q > 10).