feedback circuit


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Related to feedback circuit: negative feedback circuit

feedback circuit

[′fēd‚bak ‚sər·kət]
(electronics)
A circuit that returns a portion of the output signal of an electronic circuit or control system to the input of the circuit or system.

Feedback circuit

A circuit that returns a portion of the output signal of an electronic circuit or control system to the input of the circuit or system. When the signal returned (the feedback signal) is at the same phase as the input signal, the feedback is called positive or regenerative. When the feedback signal is of opposite phase to that of the input signal, the feedback is negative or degenerative.

The use of negative feedback in electronic circuits and automatic control systems produces changes in the characteristics of the system which improve the performance of the system. In electronic circuits, feedback is employed either to alter the shape of the frequency-response characteristics of an amplifier circuit and thereby produce more uniform amplification over a range of frequencies, or to produce conditions for oscillation in an oscillator circuit. It is also used because it stabilizes the gain of the system against changes in temperature, component replacement, and so on. Negative feedback also reduces nonlinear distortion. In automatic control systems, feedback is used to compare the actual output of a system with a desired output, the difference being used as the input signal to a controller. See Amplifier, Negative-resistance circuits, Servomechanism

References in periodicals archive ?
Placing the electrometer in the volts mode and then enabling external feedback switches the feedback circuit from an internal network to a feedback circuit connected to the preamp output.
If any of the feedback circuits are improperly specified, then the amplifier will oscillate.
The principal difference between the series and parallel feedback circuits is the phase shift between [V.
Both devices include an integrated feedback circuit that controls the DC offset and maintains 50% eye crossing.
You always had the feedback circuit built into your brain for focusing.
In particular, when the Nyquist criterium is used for VCO modeling with an open feedback circuit, it is necessary to choose the input and loading impedances carefully.
Electrification continues 1500 V, the feedback circuit of the traction current (CRCT) is isolated from ground and therefore only consists of rails and arteries and back to the substations.
This thermal feedback circuit can be useful in high-temperature environments where driving an LED at high power degrades brightness and life.
If the circuit is used with feedback from collector to base, the feedback circuit must provide additional 180 degree phase shift.
The patented Trans-impedance Amplifier invention, with a unique feedback network, works to maintain a high effective resistance value without increasing the physical size of the feedback circuit or potential drift in the amplifier's output voltage.
05 percent) and TCR tracking down to 10 ppm/K (equivalent to [+ or -]5 ppm/K), making it suitable for precision an log circuit, voltage divider, feedback circuit and signal conditioning applications.