CN2217282Y

CN2217282Y - Sound signal radio transmission arrangement

Info

Publication number: CN2217282Y
Application number: CN 94217713
Authority: CN
Inventors: 戴维鉴; 刘少光; 陈联平
Original assignee: LIANCHI INSTRUMENT FACTORY WENZHOU CITY
Current assignee: LIANCHI INSTRUMENT FACTORY WENZHOU CITY
Priority date: 1994-07-22
Filing date: 1994-07-22
Publication date: 1996-01-10
Anticipated expiration: 2004-07-22

Abstract

The utility model provides a signal radio wireless repeater, which is provided with a tandem type resistance capacity coupling circuits (C1, C3, R1, and R3), and the frequency modulation transmitting circuit of an audio signal input transmission lines (A and B), wherein, each resistance capacity coupling circuit comprises capacitance three-point oscillators (Q, C5, C6, C7, and L), and the tandem type resistance capacity coupling circuits (C1, C3, R1, and R3) are connected to the base of a generator triode (Q) in series. The utility model is characterized in that the joint of the resistors R1 and R3 which are arranged in the resistance capacity coupling circuit is bridged with a capacitance C2. The capacitance C2 and the resistors R1 and R3 are formed into a T-shaped low filter. The utility model has the advantages of high fidelity, and plump basetone.

Description

The audio signal wireless repeater

The utility model relates to a kind of frequency modulation emitter, especially relate on a kind of pickup hole that can directly be plugged on home audiovisual equipment and using, its audio signal of exporting is modulated to launches on the frequency-modulated wave for the normal audio signal wireless repeater that receives of FM receiver.

To listen music or the language that home audiovisual equipment failed with earphone and have the long many deficiencies of line in order to solve, various audio signal wireless repeaters are come out one after another.Patent Office of the People's Republic of China announced " a kind of stereo wireless headphone " on March 11st, 1992, and (notification number is: utility application CN2098766U), the disclosed technical scheme of this patent application adopts special-purpose f-m stereo acoustic emission integrated circuit (BA1404) to design, although have the high advantage of stereo emission and signal fidelity, but there is the circuit complexity, the obvious deficiency that cost is too high.Patent Office of the People's Republic of China announced again on October 7th, 1992 a kind of easy " family expenses global function wireless launcher " (notification number is: utility application CN2118370), the technical scheme of this patent application be with audio signal through the decay of capacitance-resistance series circuit be coupled to a capacitance connecting three point type oscillator modulation back by aerial radiation in the air.As everyone knows, the low frequency characteristic of capacitance connecting three point type oscillator relatively poor (relative high frequency characteristic), and the audio frequency input circuit of the described technical scheme of this patent application is a kind of common series formula capacitance-resistance attenuator circuit, to the first castering action of low frequency signal milli, so exist bass seldom abundant inevitably, deficiencies such as the relatively poor and muddiness of tonequality.In addition, do not have adjustable element in the LC frequency-selective network of the described technical scheme of this patent application, be not suitable for batch process, otherwise will inevitably have the problem of co-channel interference.

In view of the above-mentioned deficiency of existing in prior technology, the purpose of this utility model provides that the simple and high and low sound of fidelity of a kind of circuit structure is abundant, tuny audio signal wireless repeater.

The utility model realizes that the technical solution of above-mentioned purpose is to utilize standard plug that audio signal is put forward from the pickup hole of audio-visual equipment, through transmission line A, B and by capacitor C 5, C3 and resistance R 1, the resaistance-capacity coupling circuit that the R3 series connection constitutes is coupled to the base stage of triode Q, by this triode Q and capacitor C 5, C6, C7, arrive aerial after the capacitance connecting three point type oscillator modulation that inductance L constituted again by the audio signal transmission wire beta radiation, it is characterized in that resistance R 1 in the described resaistance-capacity coupling circuit, the node of R3 cross-over connection over the ground has capacitor C 2, this capacitor C 2 and resistance R 1, R3 constitutes a T type low pass filter, a part of high fdrequency component in the filtering audio signal, thus make low frequency component in the audio signal get relative lifting.

Fig. 1 is the electrical schematic diagram of a kind of specific embodiment of modulating emission circuit described in the utility model;

Fig. 2 is the schematic appearance of a kind of specific embodiments of the utility model;

Fig. 3 is many outward appearance enlarged drawings with phono plug 1 among Fig. 2.

With reference to Fig. 1, capacitor C 1, resistance R 1, R3 and capacitor C 3 are serially connected on the base stage of triode Q successively; Node cross-over connection capacitor C over the ground 2 and the resistance R 2 of resistance R 1, R3, wherein resistance R 2 and resistance R 1, R3 constitute T type attenuator jointly, and capacitor C 2 and resistance R 1, R3 constitute T type low pass filter jointly; NPN type triode Q and c thereof-b utmost point junction capacitance and capacitor C 5, C6, C7, inductance L structure capacitance connecting three point type oscillator, audio signal is after decay and filtering, carry out frequency modulation(FM) by capacitance connecting three point type oscillator, B directly is coupled to aerial emission by audio signal input transmission line.Because described T type attenuator is to the attenuation and the frequency-independent of signal, the signal of audio signal after the capacitance connecting three point type oscillator modulation must cause losing of a part of low frequency signal, thereby cause the serious distortion of signal like this.In order to remedy described deficiency, the utility model has increased a little capacitor C 2 and has promptly constituted above-mentioned T type low pass filter, and the attenuation of high-frequency signal is increased, and low frequency signal obtains relative lifting, thereby improves the fidelity of modulated signal.

With reference to Fig. 1, base stage that another ancillary technique feature of the present utility model is triode Q and audio signal input pass filter capacitor C4 of subordinate line B cross-over connection, the high fdrequency component that enters triode Q base stage is further suppressed, thus the fidelity of further improving modulated signal.

With reference to Fig. 1, resistance R 4, R5 constitute the initial bias of triode Q, regulate the resistance of resistance R 4, can adjust the quiescent point of triode Q, change transmitting power; Resistance R 5 plays stable triode Q quiescent point, for the situation at the stable DC component does not weaken alternating current component again, bypass condenser C8 in parallel on the resistance R 5 is with the AC signal shorted to earth, allow 4 pairs of AC signal of resistance R not play negative feedback, to improve oscillation intensity.

With reference to Fig. 1, capacitor C 6 is connected with variable capacitance C5 and is constituted tuning capacity jointly, regulate the master oscillator frequenc of the described capacitance connecting three point type oscillator of variable capacitance C5 scalable, carry out suitable adjusting according to environment for use and the current use frequency range of audio-visual equipment and can avoid co-channel interference effectively.

With reference to Fig. 1, capacitor C 9, C10 are power filtering capacitor, work to improve power quality.

With reference to Fig. 2, adopt technique known to be contained in the shell 3 on frequency modulation radio described in the utility model road, make the release handle of variable capacitance C5 stretch out shell 3 and connects, to make things convenient for adjusting with scale rotating disk 4; Because audio signal input transmission line A described in the utility model, B are bearing the double action of audio signal input and the emission of modulated high-frequency signal, carry out suitable selection so the length of transmission line 2 (referring to Fig. 2) should be looked the frequency of modulated high-frequency signal.Because the frequency range of general FM receiver is 88～108MHZ, so the length of transmission line 2 is advisable with 25cm～40cm.Because the specifications and models of home audiovisual equipment pickup socket are different, in order to enlarge the scope of application of the present utility model, connector 1 of the present utility model is a kind ofly to use connector more, which is provided with CSX2-2.5, CSX2-3.5 type two core connectors and CS-3 type three core connectors and lotus flower connector.

The utility model has following outstanding advantage and effect than prior art:

1, fidelity height, and bass is plentiful, the tone color grace;

2, tranmitting frequency is adjustable, can avoid co-channel interference;

3, integratedly use connector, adaptability is good more;

4, utilize audio signal input transmission line radiation modulated wave, save dedicated antenna, simple in structure, low cost of manufacture, packed and transported, carry all very convenient.

Claims

1, a kind of audio signal wireless repeater, has modulating emission circuit, this circuit comprises the capacitance connecting three point type oscillator that is made of triode Q and capacitor C 5, C6, C7, inductance L and is connected on resaistance-capacity coupling circuit and audio signal input transmission line A, the B that is connected with resistance R 1, R3 and constituted by capacitor C 1, C3 on the triode Q base stage, the node that it is characterized in that resistance R 1, R3 in described resaistance-capacity coupling circuit cross-over connection over the ground has capacitor C 2, and this capacitor C 2 constitutes a T type low pass filter with resistance R 1, R3.

2, a kind of audio signal wireless repeater according to claim 1 is characterized in that capacitor C 4 of the base stage of triode Q and audio signal input transmission line B cross-over connection.