automatic tuning control
automatic tuning control (ATC), method or device to keep a radio or television receiver automatically tuned to a desired frequency or channel. Assuming that the receiver is at least approximately tuned to the desired frequency, a circuit in the receiver develops an error voltage proportional to the degree to which the receiver is mistuned. This error voltage is then fed back to the tuning circuit in such a way that the tuning error is reduced. In most frequency modulation (FM) detectors an error voltage of this type is easily available; in television receivers extra circuits may be used to develop it. In an FM receiver, automatic frequency control (AFC) may make it difficult to receive a weak signal located near in frequency to a strong one. In tuning circuits that use frequency synthesis, in which digital circuitry, in conjunction with a crystal oscillator, produces precise signals, automatic tuning control is not necessary.
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The secret, nonspectral lives of analog-input filters.
Magazine article from: EDN; 7/24/2008; ; 585 words
; ...filter's output impedance and result in an error voltage. This simplest input filter is a passive-...the filter's capacitor and creates an error voltage, dV=dQ/C, where dQ is the injected...following an input multiplexer, the error voltage can decay only by leaking the excess...
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Charge injection creates measurement errors.(DATA ACQUISITION)
Magazine article from: Test & Measurement World; 2/1/2006; ; 246 words
; ...output impedance, it can produce an error voltage (figure). Remember that I = Q/t. If...impedance ([Z.sub.out]) will produce an error voltage ([V.sub.error]) of 4 mV. The best way...typically 1 [ohm] or less) reduces the error voltage to insignificant levels. You can download...
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Testing tells how well clock-recovery circuits counteract jitter.
Magazine article from: EDN; 4/25/1996; ; 700+ words
; ...of the two signals and produces an error voltage proportional to the difference in rates. The error voltage drives a lowpass filter. The filter...jitter frequency. Ideally, because the error voltage from the phase detector forces the...
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Myth #6: Feedback always results in output equaling the set point
Magazine article from: Hydraulics & Pneumatics; 8/1/2008; ; 700+ words
; ...amplifier. The function of the amplifier is to boost the error voltage to a higher value and, at the same time, convert the error voltage signal into an error current. The error voltage may be only a few millivolts. However, the servo or proportional...
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Designing intelligent 4-20 mA transducers: intelligent transmitters are only as good as their components. Here's how ADCs, and other low-power devices, come into play.(INTELLIGENT SYSTEMS)
Magazine article from: Sensors Magazine; 8/1/2006; ; 700+ words
; ...resistance RL2. Assuming RL1 and RL2 are equal and IOUT1 and IOUT2 match, the error voltage across RL2 cancels the error voltage across RL1, and no error voltage is developed between AIN1(+) and AIN1(-). The ADC in this example has differential...
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Closed-loop speed control of hydraulic motors
Magazine article from: Hydraulics & Pneumatics; 7/1/2006; ; 700+ words
; ...concluded in a previous edition, the error voltage cannot be zero when the control loop...rpm, and a speed gain of 40,000, the error voltage is 3000 divided by 40,000, or 0.075...minus the feedback to agree with the error voltage value. The system is in equilibrium...
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HF receiver systems.(WHAT'S HOT)
Magazine article from: Wireless Design & Development; 10/1/2003; 205 words
; ...The Model 3100 system does not use local oscillators. The desired frequency coverage is user-determined by the bandpass filters of...digital downconverters to facilitate receiver tuning to the desired frequency and recovery of the information signals. These baseband...
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Sources: voltage-controlled oscillator.(New Products)
Magazine article from: Microwave Journal; 10/1/2003; 117 words
; ...3790 to 3970 MHz within a control voltage range of 0.5 to 4.5 VDC, making it ideal for quick integration into PLLs where the error voltage can be taken directly from the IC's charge pump circuitry. In addition, the V844ME04 is sure to optimize any synthesizer...
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Ultra low noise VCO. (Sources).(advertisement)
Magazine article from: Microwave Journal; 5/1/2002; 146 words
; ...radios. It will generate frequencies between 1870 and 1890 MHz within a control voltage range of 0.5 to 2.5 V DC, allowing the error voltage to be taken directly from the IC's charge pump circuitry. This device conserves energy by drawing only 14 mA of current from...
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Surface-mount VCO.
Magazine article from: Microwave Journal; 3/1/2001; 134 words
; ...PLLs, and will generate frequencies between 2300 and 2360 MHz within a control voltage range of 0.5 to 2.5 V DC, with the error voltage being taken directly from the IC's charge pump circuitry. This device conserves energy by drawing only 8 mA of current from...
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automatic frequency control
Book article from: The Columbia Encyclopedia, Sixth Edition
see automatic tuning control .
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control systems
Book article from: The Columbia Encyclopedia, Sixth Edition
...performance specifications. Open-loop control systems (e.g., automatic toasters and alarm clocks) are those...effect on the input. Closed-loop control systems (e.g., thermostats, engine governors, automotive cruise-control systems, and automatic tuning control circuits) are ...
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radio
Book article from: The Columbia Encyclopedia, Sixth Edition
...clarity and volume. Various remote-control devices, including rocket and...satellite operations systems and automatic valves in pipelines, are activated...optimum selectivity and gain. The tuning control on a radio receiver adjusts the...
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watch
Book article from: The Columbia Encyclopedia, Sixth Edition
...hairspring and an oscillating balance wheel to control the rate at which the mechanism moves...a knob outside the watch's casing. The automatic, or self-winding, watch has a mainspring...the vibrations of an electrically driven tuning fork to determine the rate at which a...
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