CN2417633Y - Amplifier used for audio-video equipment - Google Patents

Abstract

The utility model relates to an amplifier used for audio-video equipment. In a common emitter magnifier composed of a triode G, capacitances C1 and C2, a resistor R1 and a load resistor R, the emitter load resistor R of the triode G is proportionally connected with a floating point resistor R< L > in series which is connected with the ground; the original ground terminal U< b > of an input signal is directly connected between the load resistor R and the floating point resistor R< L >. The amplified signal of the amplifier used for the audio-video equipment which adopts the structure of the utility model can not generate waveform and phase distortion, amplification factor can be simply adjusted according to people's needs, the utility model can also be made into a five-end integrated device, and therefore, the utility model can be widely used for the audio-video equipment, even all electrical equipment needing high-fidelity amplification signals.

Description

The amplifier that is used for audio and video equipment

A kind of amplifier that is used for audio and video equipment relates to the improvement of amplifier.

We are commonly used in the amplifier in the audio and video equipment, in order to obtain voltage amplification, many employing grounded emitter amplifiers, common-base amplifier (if using then negative electrode amplification, the common gates of adopting of vacuum tube circuit to amplify) more, adopting common-emitter amplifier is the most frequently used amplifier, because it has the function of the dual amplification of electric current and voltage.But because the output characteristic of this amplifier is constant-current characteristics, the output impedance height, load characteristic is relatively poor, and the waveform distortion of its output signal is bigger.For overcoming wave distortion, people generally on the basis of adopting multistage common emitter to amplify, revise by the additional depth negative-feedback circuit.Like this, wave distortion can reduce relatively, but brings the repeatedly displacement of signal phase thereupon.And in audio and video equipment, very responsive to the phase distortion of signal, in common-emitter amplifier, be not have effective solution therefore.Adopt common-base amplifier, can accomplish input/output signal phase place unanimity, but because its output characteristic still belongs to constant-current characteristics, and output impedance is high, load characteristic is poorer.

The purpose of this utility model, be to provide a kind of amplifier that is used for audio and video equipment, good load characteristic both can have been arranged, can guarantee input/output signal waveform homophase again, there is not wave distortion, at the high-fidelity voltage amplification signal that does not need to obtain under the degenerative situation of other plus depth high multiple.

The utility model is to implement like this, and by triode G1, capacitor C, C2 in the common-collector amplifier that resistance R 1, load resistance R form, on the emitter-base bandgap grading load resistance R of triode G, is connected in series a floating-point resistance R in proportion _LGround connection is with the former earth terminal U of input signal _bDirectly be connected on load resistance R and floating-point resistance R _LBetween form.

Below in conjunction with accompanying drawing in detail structure of the present utility model and principle are described in detail:

Fig. 1 is the amplifier schematic diagram that is used for audio and video equipment described in the utility model;

Fig. 2 is the amplifier electrical schematic diagram that is used for audio and video equipment that adopts electron tube to form;

Fig. 3 is the wiring electrograph when adopting transformer to do signal coupling input;

Fig. 4 is the electrical schematic diagram that connects the amplifier that is used for audio and video equipment of electron tube composition when adopting transformer to do signal coupling input;

Fig. 5 is the wiring circuit diagram when adopting the common emitter amplifying circuit to make input signal;

Fig. 6 is the electrical schematic diagram that connects the amplifier that is used for audio and video equipment of electron tube composition when adopting the common cathode amplifying circuit to make input signal.

As shown in Figure 1, the audio-video signal that amplifies in order to guarantee does not produce wave distortion and phase distortion, we adopt the common-collector amplifier of being made up of triode G, capacitor C 1, C2, resistance R 1, load resistance R to do the basis, wherein on the emitter-base bandgap grading load resistance R of triode G, be connected in series a floating-point resistance R in proportion _LGround connection is with the former earth terminal U of input signal _bDirectly be connected on load resistance R and floating-point resistance R _LBetween form.Like this, owing to floating-point resistance R this moment _LGround connection, and floating-point resistance R _LWith the ratio of load resistance R greater than more than 2, work as U _AbIt is 1 o'clock, at U _{Go out}Just can obtain one greater than the homophase output signal more than 2 times, satisfy the requirement of audio and video equipment amplifying signal.

When the amplifier that is used for audio and video equipment is when forming with electron tube, as shown in Figure 2, on negative electrode output load resistance R, be connected in series a floating-point resistance R in proportion by anode amplifier altogether _LGround connection is the former earth terminal U of input signal _bDirectly be connected on load resistance R and floating-point resistance R _LBetween form.Its electric principle is the same with transistor, as input signal U _AbWhen being added in negative electrode and grid, at the amplifying signal U that negative electrode took out _{Go out ＇}Just can with U _{Ab ＇}The same-phase same waveform, and its multiplication factor equals R _L: R＞more than 2.

In actual applications, when input signal is done the coupling input by transformer, can be as shown in Figure 3, the L of the former earth terminal of transformer secondary output _BDirectly be connected on load resistance R and floating-point resistance R _LBetween, can obtain equally the phase place and the U of multiplication factor＞2 from the output of the amplifier that is used for audio and video equipment _BbConsistent amplification audio-video voltage signal.If amplifier is to adopt electron tube to form, as shown in Figure 4, as long as transformer secondary output L _aTerminate on the grid of amplifier tube, L _BEnd directly is connected on load resistance R and floating-point resistance R _LBetween, at the output U of amplifier _{Go out}Just can obtain a multiplication factor greater than the audio-video amplifying signal of the waveform more than 2, phase place unanimity.

Have in the audio and video equipment of specific (special) requirements at some, in order to guarantee enough big multiplication factor, also adopt common-emitter amplifier to make the said input signal source that is used for the amplifier of audio and video equipment of the utility model, as shown in Figure 5, at this moment should pass through sampling load resistance R at the collector electrode C place of common-emitter amplifier _cDirectly be connected on the load resistance R and the floating-point resistance R of the amplifier that originally is used for audio and video equipment _LBetween form because the input signal U of the amplifying circuit of prime _{Go into}Through after the amplification of common-emitter amplifier,, under all distortionless situation of the waveform that has guaranteed signal, phase place, continue to obtain R again by the said amplifier that is used for audio and video equipment of the utility model _L: the amplification quantity that R＞2 are above, if this moment is the amplifier that adopts electron tube to form, and as shown in Figure 6, the signal that prime has been amplified is from sample resistance R _{C '}Directly be added in the load resistance R and the floating-point resistance R of the amplifier that originally is used for audio and video equipment _LBetween, just can obtain a U at the output of amplifier _{Go out}Audio-video voltage signal more than＞2.

The said amplifier that is used for audio and video equipment of the utility model because technology is simple, can be cured as it five terminal integrated device, wherein, and said floating-point resistance R _LWith the ratio of load resistance R, can make different ratios, generally get R _LThan R is each sequence more than 2.Like this, people can choose the amplifying device of different proportion by the requirement of each circuit when using this amplifier.

Adopted the amplifier that is used for audio and video equipment of the said structure of the utility model, because the signal after amplifying can not produce waveform and phase distortion, multiplication factor can need simple and easy adjustment with people, therefore not only can be used for audio and video equipment, as the video amplifier, look audio-frequency power amplifier, even can be used among all electric equipments, obtain the amplifying signal of high-fidelity.

Claims (2)

1, a kind of amplifier that is used for audio and video equipment in the common emitter amplifier of being made up of triode G, capacitor C 1, C2, resistance R 1, load resistance R, is characterized in that being connected in series a floating-point resistance R in proportion on the emitter-base bandgap grading load resistance R of triode G _LGround connection is with the former earth terminal U of input signal _bDirectly be connected on load resistance R and floating-point resistance R _LBetween form.

2, according to the said amplifier that is used for audio and video equipment of claim 1, it is characterized in that said floating-point resistance R _LWith the ratio of load resistance R should be greater than more than 2.

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