CN2560183Y - Infrared frequency-modulated audio receiving three-purpose language learning earphone - Google Patents

Abstract

A three-function language-learning earphone to receive the infrared, frequency modulation and audio frequency of the utility model consists of an infrared receiving circuit, a frequency modulation receiving circuit, an audio frequency receiving circuit, an intermediate frequency amplification and modulation circuit, a power amplification circuit and a loudspeaker. The infrared receiving circuit and the frequency modulation receiving circuit are connected with the intermediate frequency amplification and modulation circuit through a function switch, then connected in parallel with the power amplification circuit together with the audio frequency receiving circuit through the function switch and then connected with the loudspeaker. The utility model can receive three sending types, namely the infrared, frequency modulation and audio frequency and is characterized by simple structure, easy usage, which is economical and practical.

Description

Infrared frequency modulation audio is accepted three and is used earphone for language study

The utility model relates to a kind of earphone for language study, and particularly a kind of infrared frequency modulation audio is accepted three and used earphone for language study.

Existing known earphone for language study all has only one or both accepting methods, do not possess a machine and accept the function of infrared, frequency modulation, three kinds of radiation patterns of audio frequency, when, frequency modulation infrared, three kinds of radiation patterns of audio frequency when accepting, must use one pair of above earphone for language study, the learner is very inconvenient.

The purpose of this utility model is to propose a kind of infrared frequency modulation audio acceptance three that can accept infrared, frequency modulation, three kinds of radiation patterns of audio frequency on one pair of earphone for language study to use earphone for language study.

Task of the present utility model is finished like this: infrared frequency modulation audio is accepted three usefulness earphone for language study and is accepted by infrared that circuit, frequency modulation are accepted circuit, audio frequency is accepted circuit, intermediate frequency amplification and demodulator circuit, power amplification circuit and loud speaker B1B2 and formed, infrared accept circuit and frequency modulation accept circuit by functional switch S2-2 be connected intermediate frequency amplify with demodulator circuit on, accept circuit with audio frequency again and be attempted by on the power amplification circuit, receive loud speaker B1B2 again by functional switch S2-4.The infrared circuit of accepting is mainly accepted triode V8, V9 that diode V4, V5, V6, V7 connect series connection, V10 etc. by parallel connection infrared and is formed, and V8 is used for common emitter and amplifies, and V9, V10 are direct coupling and frequency selective amplifier; Frequency modulation is accepted circuit and mainly is made up of 8,9 pin of capacitor C 1 and inductor L1, L2, capacitor C 2-1, C2-2, C3, C2-3, C2-4, C4 and integrated circuit CAX1191M in parallel and the high-frequency amplifier circuit of inside thereof etc., and L1, C2-1, C2-2, C3 are connected to the frequency modulation selective frequency amplifier circuit by 8, the 9 pin high-frequency amplifier circuit inner with it of integrated circuit CAX1191M; Audio frequency accept circuit mainly by the series connection voltage amplification diode V1, V2 etc. form, be the direct coupled voltages amplifying circuit of two-stage; Intermediate frequency amplifies and the inside of demodulator circuit at integrated circuit CAX1191M; Power amplification circuit connects into the OTL audio-frequency power amplifier by the external capacitor C 13 of electronic sound volume controller, a utmost point preamplifier and integrated circuit CAX1191M23,24,25,26 thereof, 27 pin of electric capacity inside, C14, C15, C16, C17, C18, C19, C20 etc.

The utlity model has characteristics simple in structure, easy to use, economical and practical.

Below in conjunction with accompanying drawing the utility model is described in further detail.

Fig. 1 is that this practical infrared frequency modulation audio is accepted three usefulness language learning head circuit figure.

According to shown in Figure 1: the infrared frequency modulation audio of the utility model is accepted three and is used earphone for language study, by the infrared circuit (1) of accepting, frequency modulation is accepted circuit (2), audio frequency is accepted circuit (3), intermediate frequency amplifies and demodulator circuit (4), power amplification circuit (5), form with loud speaker B1B2 (6), infrared accept circuit (1) and frequency modulation accept circuit (2) by functional switch S2-2 (37) be connected intermediate frequency amplify with demodulator circuit (4) on, accept circuit (3) with audio frequency again and be attempted by on the power amplification circuit (5), receive loud speaker B1B2 (6) again by functional switch S2-4 (34).The infrared circuit (1) of accepting is mainly accepted triode V8 (11), V9 (12) that diode V4 (7), V5 (8), V6 (9), V7 (10) connect series connection, V10 (13) etc. by parallel connection infrared and is formed, V8 (11) is used for common emitter and amplifies, and V9 (12), V10 (13) are direct coupling and frequency selective amplifier; Frequency modulation is accepted circuit (2) and mainly is made up of with 8,9 pin of integrated circuit CAX1191M (23) and inner high-frequency amplifier circuit thereof etc. capacitor C 1 (14) and in parallel inductor L1 (15), L2 (16), capacitor C 2-1 (17), C2-2 (18), C3 (19), C2-3 (20), C2-4 (21), C4 (22), and L1 (15), C2-1 (17), C2-2 (18), C3 (19) are connected to the frequency modulation selective frequency amplifier circuit by 8, the 9 pin high-frequency amplifier circuit inner with it of integrated circuit CAX1191M (23); Audio frequency is accepted circuit (3) and mainly is made up of voltage amplification diode V1 (24), the V2 (25) etc. of series connection, is the direct coupled voltages amplifying circuit of two-stage; Intermediate frequency amplifies and the inside of demodulator circuit (4) in integrated circuit CAX1191M (23); Power amplification circuit (5) connects into the OTL audio-frequency power amplifier by the external capacitor C 13 (26) of integrated circuit CAX1191M (23) inner electronic sound volume controller, a utmost point preamplifier and 23,24,25,26,27 pin thereof, C14 (27), C15 (28), C16 (29), C17 (30), C18 (31), C19 (32), C20 (33) etc.

During work: 1, audio frequency is accepted circuit (3) and is sensed audio-frequency electric magnetic wave by transmitter emission after diode V1 (24), V2 (25) carry out voltage amplification from inductor L3 (38), switching by functional switch S2-4 (34), be coupled into the 24th pin of power amplification circuit (5) integrated circuit CAX1191M (23) through capacitor C 15 (28), after portion carries out voltage and power amplification within it, the 27th pin output from integrated circuit CAX1191M (23), through capacitor C 20 (33) couplings, promote loud speaker B1B2 (6) sounding again.

2, frequency modulation is accepted the FM radio station signal that circuit (2) receives and is responded to through antenna W1 (35), capacitor C 1 (14) is coupled to the 12nd pin of intermediate frequency amplification and demodulator circuit (4) integrated circuit CAX1191M (23), through capacitor C 1 (14), C2-1 (17), C2-2 (18), the 8th of C3 (19) and integrated circuit CAX1191M (23) thereof, 9 pin connect the internal circuit frequency-selecting and amplify (even circuit signal and local oscillation beat are transformed into fixing 10, the intermediate-freuqncy signal of 7MHz), amplified IF signal enters 17 pin of CAX1191M (23) through intermediate-frequency filter Z1 (36) transmission from the 14 pin output of CAX1191M (23), portion carries out frequency discrimination taking-up audio signal within it, export from 23 pin of CAX1191M (23) again, through capacitor C 15 (28) couplings, be input into 24 pin of power amplification circuit (5) integrated circuit CAX1191M (23), after power amplification is carried out in CAX1191M (23) inside, export from CAX1191M (23) the 27th pin, by capacitor C 20 (33) couplings, promote loud speaker B1B2 (6) sounding.

3, the infrared infrared receiving tube V4 (7) that accepts in the circuit (1), V5 (8), V6 (9), V7 (10) will be converted to high frequency electrical signal by the infrared light that infrared transmitter emits through capacitor C 3 (19) couplings, the preamplifying circuit of forming via V8 (11) carries out voltage amplification, again through V9 (12), V10 (13) secondary frequency-selecting is amplified, with select 10, the 7MHz FM signal is switched the inside of sending into intermediate frequency amplification and demodulator circuit (4) integrated circuit CAX1191M (23) via band switch S2-3 (39) and is carried out intermediate frequency amplification and frequency discrimination, export from 23 pin of CAX1191M (23) then, be input into 24 pin of power amplification circuit (5) integrated circuit CAX1191MD (23) by capacitor C 15 (28) couplings, portion carries out the audio power amplification within it, export from 27 pin of CAX1191M (23) again, through capacitor C 20 (33) couplings, promote loud speaker B1B2 (6) sounding.

Infrared, frequency modulation, three kinds of receive modes of audio frequency are switched the conversion of finishing different receive modes by functional switch S2-1 (40).

Claims (2)

1, a kind of infrared frequency modulation audio is accepted three and is used earphone for language study, it is characterized in that accepting by the infrared circuit (1), frequency modulation accepted that circuit (2), audio frequency are accepted circuit (3), intermediate frequency amplifies and demodulator circuit (4), power amplification circuit (5) and loud speaker B1, B2 (6) form, infrared accept circuit (1) and frequency modulation accept circuit (2) by functional switch S2-2 (37) be connected intermediate frequency amplify with demodulator circuit (4) on, accept circuit (3) with audio frequency again and be attempted by on the power amplification circuit (5), receive loud speaker B1B2 (6) again by functional switch S2-4 (34).

2, infrared frequency modulation audio according to claim 1 is accepted three and is used earphone for language study, it is characterized in that the infrared main infrared diode V4 (7) that accepts of circuit (1) that accepts by parallel connection, V5 (8), V6 (9), V7 (10) connects the triode V8 (11) of series connection, V9 (12), V10 compositions such as (13), frequency modulation is accepted circuit (2) mainly by C1 (14) and inductor L1 (15) in parallel, L2 (16), capacitor C 2-1 (17), C2-2 (18), C3 (19), C2-3 (20), C2-4 (21), C4 (22), 8 of integrated circuit CAX1191M (23), 9 pin and inner compositions such as high-frequency amplifier circuit thereof, audio frequency is accepted circuit (3) mainly by the voltage amplification diode V1 (24) that connects, V2 compositions such as (25) is the direct coupled voltages amplifying circuit of two-stage; Intermediate frequency amplifies and the inside of demodulator circuit (4) in integrated circuit CAX1191M (23); Power amplification circuit (5) connects into the OTL audio-frequency power amplifier by the external capacitor C 13 (26) of integrated circuit CAX1191M (23) inner electronic sound volume controller, a utmost point preamplifier and 23,24,25,26,27 pin thereof, C14 (27), C15 (28), C16 (29), C17 (30), C18 (31), C19 (32), C20 (33) etc.

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