CN2598256Y

CN2598256Y - Transistor impedance transformer

Info

Publication number: CN2598256Y
Application number: CNU032191588U
Authority: CN
Inventors: 常德胜
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-03
Filing date: 2003-01-03
Publication date: 2004-01-07
Anticipated expiration: 2013-01-03

Abstract

The utility model discloses a transistor impedance transformer which comprises a single-end input audio power amplifier. The utility model is characterized in that: the input terminal of the single-end input audio power amplifier bridges over ground with a pull-down inductance (L). The power amplifier made according to the technical proposal of the utility model has a dynamic loudspeaker ranging from two to sixteen Ohms in free mating with good sound reducibility, clear and vigorous tone quality.

Description

The transistor impedance transformer

Technical field:

The utility model relates to electronic technology field, relates to a kind of impedance conversion device, and especially transistor impedance parallel operation is applicable to the final stage amplification of making audio signal.

Background technology:

Loud speaker is generally all used in the final stage load of stereo set, because the AC impedance of loud speaker is lower, and changes with frequency input signal, therefore common crystal amplifier is difficult to meet the demands.In order to make load obtain effective, suitable power, adopt transformer to carry out impedance matching in the common circuit.As everyone knows, carry out with transformer that impedance matching exists that volume is big, power consumption is big, the many deficiencies of matching frequency scope Chad.Patent Office of the People's Republic of China's Granted publication on November 22nd, 2000 a kind of " low power dissipation electron impedance transformer " utility model patent, the disclosed technical scheme of this utility model patent comes down to the two-stage electron-amplifier, its no-load voltage ratio is relevant with the ratio of external biasing resistor and feedback resistance, and used element all is a linear element, for the such inductive load of loud speaker with amplify and still have following deficiency the high-power audio signal: 1, power factor is low, and reactive loss is big; 2, driving Low ESR inductive load mismatch joins seriously; 3, Hz-KHz is little, and distortion is serious, lower tone.

Summary of the invention:

Technical problem to be solved in the utility model is: audio frequency power amplifier and the low technical barrier of the serious power factor of inductive load mismatch.

The utility model will solve the problems of the technologies described above technical solution: a kind of transistor impedance transformer, comprise single-ended input audio-frequency power amplifier, and the input that it is characterized in that single-ended input audio-frequency power amplifier is cross-over connection one drop-down inductance over the ground.

The following outstanding advantage of the utility model:

1, matching is good under the current intelligence, the power factor height, and on average greater than 0.75, effective power improves 4 times, i.e. 6db;

2, frequency response is wide, and the experimental data of the power amplifier of 30W is:

Voltage frequency response :-10db 15Hz～1.5MHz ± 0.5db

The power frequency response? 0db 20Hz～500KHz ± 1.5db

-3db 20Hz～1MHz±1db

3, matching range is wide, all good couplings of energy of raising one's voice from 16～2;

4, distortion is little, and tonequality is good.

Embodiment:

Fig. 1 is the voltage schematic diagram of a specific embodiment of the present utility model; Fig. 2 is the electrical schematic diagram of a most preferred embodiment of the present utility model.

Example 1:

Referring to Fig. 1, the selection of the reactance size of inductance described in the utility model should be suitable, and the too little loss of signal is big, generally is advisable with 1～100H.

Referring to Fig. 1, IC is commercially available ordinary audio power discharging integrated block in the present embodiment, and being serially connected in IC input coupling capacitance C is 10～150 microfarads, R _LBe 4 Europe electrodynamic loudspeakers.

Example 2:

Referring to Fig. 2, single-ended input audio-frequency power amplifier described in the present embodiment is made of a holohedral symmetry shunt voltage follower, and triode T1 and T3 form a voltage follower, and triode T2 and T4 form another voltage follower.Transmit the base stage that audio signal is delivered to triode T1, T2 by coupling capacitance C1, connect with ground, therefore reached real feed at zero point because inductance L is connected across the base stage of triode T1, T2; If amplifying by resistance R 3 and capacitor C 2 through triode T1 for positive polarity, described signal is coupled to triode T3 driving loud speaker R _LIf described signal drives loud speaker R for negative polarity is coupled to triode T4 through triode T2 amplification by resistance R 3 and capacitor C 2 _LThe value of capacitor C 1 and inductance L in the present embodiment, reference example 1 is implemented to get final product.

Utilize this to implement the 30W power amplifier that described technical scheme is made, 2～16 Europe electrodynamic loudspeakers can freely mate, and sound-reducing is good, sound clarity, simple and honest.

Claims

1, a kind of transistor impedance transformer comprises single-ended input audio-frequency power amplifier, and the input that it is characterized in that single-ended input audio-frequency power amplifier is cross-over connection one drop-down inductance (L) over the ground.

2, a kind of transistor impedance transformer according to claim 1, the induction reactance that it is characterized in that described inductance is 1～100H.