In electronics, Anderson's bridge is a bridge circuit used to measure the self-inductance of the coil. It enables measurement of inductance by utilizing other circuit components like resistors and capacitors. [1]
Anderson's bridge was invented by Alexander Anderson in 1891. [2] He modified Maxwell's inductance capacitance bridge so that it gives very accurate measurement of self-inductance. [3]
The balance conditions for Anderson's bridge or, equivalently the values of the self-inductance and resistance of the given coil can be found using basic circuit analysis techniques such as KCL, KVL and using phasors. Consider the circuit diagram of Anderson's bridge in the given figure. Let L1 be the self-inductance and R1 be the electrical resistance of the coil under consideration. Since the voltmeter is ideally assumed to have nearly infinite impedance, the currents in branches ab and bc and those in the branches de and ec are taken to be equal. Applying Kirchhoff's current law at node d, it can be shown that-
Since the analysis is being made under the balanced condition of the bridge, it can be said that the voltage drop across the voltmeter is essentially zero. On applying Kirchhoff's voltage law to the appropriate loops(in the anti-clockwise direction), the following relations hold-
On solving these sets of equations, one can finally obtain the self-inductance and resistance of the coil as-
The Anderson's bridge can also be used the other way round- that is, it can be used to measure the capacitance of an unknown capacitor using an inductor coil whose self-inductance and electrical resistance have been pre-determined to a high degree of precision. An interesting point to note is the fact that the measured self-inductance of the coil does not change even on taking dielectric loss within the capacitor into account. Another advantage of using this modified bridge is that unlike the variable capacitor used in Maxwell bridge, it makes use of a fixed capacitor which is relatively quite cheaper. [4]
One of the obvious difficulties associated with Anderson's bridge are the relatively complex balance equation calculations compared to the Maxwell bridge. The circuit connections and computations are similarly more cumbersome in comparison to the Maxwell bridge. [5]
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In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit.
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A resistor–inductor circuit, or RL filter or RL network, is an electric circuit composed of resistors and inductors driven by a voltage or current source. A first-order RL circuit is composed of one resistor and one inductor, either in series driven by a voltage source or in parallel driven by a current source. It is one of the simplest analogue infinite impulse response electronic filters.
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A Maxwell bridge is a modification to a Wheatstone bridge used to measure an unknown inductance in terms of calibrated resistance and inductance or resistance and capacitance. When the calibrated components are a parallel resistor and capacitor, the bridge is known as a Maxwell bridge. It is named for James C. Maxwell, who first described it in 1873.
In electrical engineering, dielectric loss quantifies a dielectric material's inherent dissipation of electromagnetic energy. It can be parameterized in terms of either the loss angleδ or the corresponding loss tangenttan(δ). Both refer to the phasor in the complex plane whose real and imaginary parts are the resistive (lossy) component of an electromagnetic field and its reactive (lossless) counterpart.
Zobel networks are a type of filter section based on the image-impedance design principle. They are named after Otto Zobel of Bell Labs, who published a much-referenced paper on image filters in 1923. The distinguishing feature of Zobel networks is that the input impedance is fixed in the design independently of the transfer function. This characteristic is achieved at the expense of a much higher component count compared to other types of filter sections. The impedance would normally be specified to be constant and purely resistive. For this reason, Zobel networks are also known as constant resistance networks. However, any impedance achievable with discrete components is possible.
An RLC circuit is an electrical circuit consisting of a resistor (R), an inductor (L), and a capacitor (C), connected in series or in parallel. The name of the circuit is derived from the letters that are used to denote the constituent components of this circuit, where the sequence of the components may vary from RLC.
