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Class B vacuum tube amplifiers are usually operated with grid current (class B 2). The bias voltage source must have low resistance and be able to supply the grid current. [3] When tubes designed for class B are employed, the bias can be as little as zero. Class C amplifiers are biased negatively at a point well beyond plate current cutoff ...
Plate detector circuit with cathode bias. Cathode bias RC time constant three times period of lowest carrier frequency. C L is typically around 250 pF.. In electronics, a plate detector (anode bend detector, grid bias detector) is a vacuum tube circuit in which an amplifying tube having a control grid is operated in a non-linear region of its grid voltage versus plate current transfer ...
The sensors which transimpedance amplifiers are used with usually have more capacitance than an op-amp can handle. The sensor can be modeled as a current source and a capacitor C i. [4] This capacitance across the input terminals of the op-amp, which includes the internal capacitance of the op-amp, introduces a low-pass filter in the feedback path.
Typical push–pull audio tube power amplifier, matched to loudspeaker with an impedance-matching transformer Audio amplifiers typically do not match impedances, but provide an output impedance that is lower than the load impedance (such as < 0.1 ohm in typical semiconductor amplifiers), for improved speaker damping .
The pentode EL84/6BQ5 - 9 pin Noval base tube, that although different enough from the 6V6 not to justify rating it as an equivalent, because of its popularity and ready availability, plus having a close-enough similarity to make it possible, if bias is altered, adapters have been developed commercially to allow an amplifier designed for 6V6 ...
Feedback-free instrumentation amplifier is the high-input-impedance differential amplifier designed without the external feedback network. This allows reduction in the number of amplifiers (one instead of three), reduced noise (no thermal noise is brought on by the feedback resistors) and increased bandwidth (no frequency compensation is needed).
In electronics engineering, frequency compensation is a technique used in amplifiers, and especially in amplifiers employing negative feedback.It usually has two primary goals: To avoid the unintentional creation of positive feedback, which will cause the amplifier to oscillate, and to control overshoot and ringing in the amplifier's step response.
The semiconductor or vacuum tube conducts throughout the entire RF cycle. The mean anode current for a vacuum tube should be set to the middle of the linear section of the curve of the anode current vs grid bias potential. Class-B amplifiers can be 60–65% efficient. The semiconductor or vacuum tube conducts through half the cycle but requires ...