RU1816327C - Sound device - Google Patents

Abstract

The invention relates to the field of instrumentation and can be used in audio devices. In order to reduce the area of adaptive use of tape recorders (such as a player) with industrial, automobile and portable radios by providing independent remote control of the sound level of a tape recorder, the device contains a tape recorder (1), a tape recorder head (2), an amplifier (3), a control unit (4 ) containing a modulation parameter controller (5), an electronic key (6), a generator (7), a radio receiver (8), an antenna (9), a receiver (10), an amplifier (11), a loudspeaker (12). 2 ill.

Description

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The invention relates to radio electronics and can be used in the design and operation of audio devices, especially when using a radio receiver and an individual listening tape recorder or tape recorder without built-in speaker units.

The aim of the invention is to simplify the sound device and expand the field of adaptive use of player type tape recorders, preferably with car and portable radios, by providing independent control of the sound level of the tape recording.

In FIG. 1 shows a structural diagram of the proposed device; in FIG. 2 is a diagrammatic embodiment of a generator control unit consisting of a modulation parameter controller and an electronic key;

The audio device contains a tape recorder 1, including the head of a tape recorder 2, connected to an amplifier 3, the output of which is connected to a common point of the control unit 4, which has a modulation parameter controller 5 connected in parallel and / / an electronic key 6, and the common output of the control unit 4 is connected to a generator 7 carrier frequency, supplying a signal to the radio 8 through the antenna 8 connected to the input of the receiver 10, which is connected in series through the amplifier 11 to the loudspeaker 12.

In this embodiment, the output of the amplifier 3 of the magnetic head 2 is connected through a capacitor C1 of a modulation parameter controller 5, which is connected in series to a resistor P1 and a capacitor C2, and their outputs are connected to adjustable resistors R2 and R7. The second terminals of resistor R2 are connected to resistor R3 through parallel connected capacitors C3 and C4, and the second terminals of resistor R7 are connected to capacitors C2 and C5. , The common point of the resistors R3 and R4 is connected to the operational amplifier V and the output of this amplifier is connected to the resistors R8 and R13 and through the capacitor C8 to the input of the generator 7.

The modulation parameter controller 5 is connected in parallel with resistor R5 and resistors R11.R12 by capacitor C7 of electronic key 6.

Resistor R5 is connected through a common point with resistor R6, diode VD, and the base of transistor VT1, and its collector with resistor R9 and capacitor Sat. The common point of the resistors R9, R10 is connected to the base of the transistor VT2, its collector with the resistor R11, and the emitter with the resistor R10 and the oscillatory circuit of the oscillator 7. The output of the modulation parameter controller 5 is connected

with the base of transistor VT3 of generator 7, its emitter with capacitors CJ, C 11 and resistor R14, and a collector with an oscillatory circuit consisting of coil L11 and capacitor C9.

The modulation parameter controller 5 is based on the use of a negative feedback operational amplifier such as K157, K159, K553, K140. In another embodiment of the modulation parameter controller, passive LC and RC links can be used.

The electronic key 6 is built using an H4 signal detector and a switching transistor of the type KT315, KT361, CT

3102, KT3107. The switching element can be performed on IC chips 157,

UD 140 UD 20,

Generator 7 is constructed on the principle of a self-oscillating generator with a common base, wherein the emitter is an oscillating circuit.

The generator can be performed as a self-oscillating generator with a common emitter, with a common collector, and by the method

positive feedback can be modulated or capacitive

three point. The generator can be made

on a tunnel diode or CT transistors

315, KT368, KT316, KT361.

The sound device operates as follows.

When the cassette is inserted and the tape recorder 1 is turned on, the emerging signal recorded on the magnetic tape is sensed by the head 2 of the tape recorder 1 through the amplifier 3 of the magnetic head 2 by means of the electronic key 6 of the control unit 4, the carrier frequency generator 7 is switched on, which is modulated by the signal on the magnetic tape. The signal level (i.e., timbre and volume) is set by the modulation parameter knob 5 associated with the available controls of tape recorder 1 (not shown) by changing

generator carrier frequency modulation level 7.

Further, the signal emitted by the generator 7 is received by the antenna 9 of the radio receiver 8 tuned to a predetermined frequency of the receiver 10 and converted through the amplifier 11 into the sound signal of the speaker 12.

Thus, the signal recorded on the magnetic tape can be heard individually through the linear output of the tape recorder 1 using phones (headphones)

and through the loudspeaker 12 of the VHF radio receiver 8 located at a distance of up to 3 m from the tape recorder 1 within the range of the radiation power of the signal of the generator 7, the carrier frequency of 73 MHz, while the volume level and timbre can be set by both the controls of the tape recorder 1 and the radio receiver 8, and the radiation of the signal of the generator 7 due to the electronic key 6 occurs only when there is a signal on the magnetic tape and when it stops or for long pauses of the generator 7 is turned off.

When the sound device as a whole is operating, the control unit 4 is a modulation parameter controller 5 in the form of an inverting amplifier covered by a frequency-dependent negative feedback through a classical bridge circuit made on the elements R1, R2, R3, R4. R7, R8, C1, C3, C4, C2, C5. A signal to control unit 4 is provided from signal amplifier 3. magnetic head 2 through capacitor C1. Tone control is performed by variable resistors R2 and R7, and the modulation level is performed by variable resistor P13.

The electronic key b controlling the radiation of the generator 7 is made on transistors VT1 and VT2. The electronic switch 6 turns on the generator 7 for radiation only if there is a sound signal at the input of the control unit 4. The signal to the electronic switch 6 is supplied from the output of the signal amplifier 3 of the magnetic head 2 through a divider on resistors R5, R6 to a signal detector made on transistor VT1 and diode VD, and the detector load is resistors R9 and R10. Capacitor C6 determines the large time constant of the detector (about 10 seconds) necessary to maintain the key state during short breaks in the audio signal recorded on magnetic tape.

Transistor VT2 is a detector signal amplifier and operates in key mode. If there is an audio signal at the detector input, the transistor VT2 goes into saturation mode by connecting the power supply plus to the divider on resistors R11, R12. The constant voltage from the divider R11, R12 is applied to the base of the transistor VT3 of the working generator 7 and controls its radiation. Capacitor C7 closes the base of the transistor VT3 at a high frequency on a common wire.

When performing an audio device, the control unit together with the generator is built into the cassette recorder body, or is made as a separate unit connected to the linear output of the recorder.

Compared to the selected prototype, the inventive sound device with circuit simplifications by providing independent control of the sound level of the magnetic recording expands the adaptive use of player type tape recorders in conjunction with car and portable radios.

Claims (1)

The claims An audio device comprising a radio receiver with a loudspeaker and a tape recorder with a control unit, a carrier frequency generator and a low frequency amplifier, characterized in that the control unit is made in the form of parallel connected modulation parameter controller and an electronic key and is connected between the low frequency amplifier and the carrier frequency generator. 3L-J