JPS5819759Y2 - Radio Tsuki Tape Recorder - Google Patents

Description

[Detailed explanation of the invention] A tape recorder with a radio that combines a radio receiver and a cassette tape recorder is widely used.
In this tape recorder with a radio, the radio and tape recorder are integrated, so the speaker is inevitably smaller compared to a tape recorder of the same size, and as a result, low frequencies are not reproduced (4) and the reproduced sound is not powerful. It becomes 1.

Also, even if the bass is coming out, the IC feels like the bass is missing due to the loudness characteristics.

The present invention has been developed in view of these points, and an object of the present invention is to provide a tape recorder with a radio that can enhance the low frequency range during broadcast reception using a particularly simple configuration.

For this reason, in the present invention, during radio reception, the low frequency range of the detected signal is amplified by a playback equalizer amplifier in the tape recorder section.An example of this will be explained below.

In Figure 1, 1 to 3 indicate the radio/tape recorder changeover switch, contact B is the radio side contact, and contact T
is a contact on the tape recorder side.

Further, 11 to 15 indicate recording/reproduction changeover switches,
In the figure, it is connected to the playback side contact P.

Furthermore, 21 is a transistor whose eminter is grounded;
Reference numeral 2 denotes a preamplifier, which is constructed by directly connecting transistors 23 and 24 whose emitters are grounded.

Further, 25 is a main amplifier, which has an emitter-grounded transistor 26 and push-pull connected transistors 27 and 28.

Further, 31 is a tuner circuit (receiving circuit) including a detection stage of the radio section, 32 is a built-in microphone, and 33 is a recording/reproducing magnetic head.

Further, 34 is a bias oscillation circuit, 35 is a variable resistor for volume adjustment, and 36 is a speaker.

When the tape recorder is playing, switches 1 to 3 are connected to contact T, contrary to the diagram, and switches 11 to 15 are connected to contact T.
is connected to contact PK as shown in the figure.

Then, one end of the head 33 is grounded through the contact P of the switch 11, and the other end of the head 33 is connected to the base of the transistor 210 through the contact P of the switch 12, so that the reproduced signal from the head 33 is connected to the transistor 210.
1 and amplified.

The amplified signal from the transistor 21 is supplied to the preamplifier 22 through the contact T of the switch 1 and amplified, and this amplified signal is further supplied to the main amplifier 25 through the variable resistor 35 for power amplification. The amplified output is supplied to the speaker 33 through the contact P of the switch 13, and the tape is played back.

In this case, the collector of the transistor 24 is connected to the emitter of the transistor 23 through the contact P of the switch 14 → the contact T of the switch 2 → the reproduction equalizer element 41 to perform negative feedback, and the amplifier 22 is used as an equalizer amplifier during reproduction. It is said that

Further, when the tape recorder records, switches 1 to 3 are connected to the contact T, contrary to the figure, and switches 11 to 15 are also connected to the recording side contact R, contrary to the figure.

Therefore, the signal from the microphone 32 is transmitted to the switch 12.
The signal from the amplifier 22 is supplied to the head 33 through the contact R of the switch 15 → the bias trap circuit 37 → the recording equalizer 38. At the same time, the other end of the head 33 is grounded through the contact R of the switch 11, and the signal from the microphone 32 is recorded.

In this case, the collector of the transistor 24 is connected to the transistor 23 through the contact R of the switch 14 and the resistor 42.
is connected to the emitter of the amplifier 22, and the amplifier 22 is a flap amplifier.

Furthermore, at this time, the signal from the amplifier 22 is transmitted to the switch 1.
The AGC voltage is supplied to the rectifier circuit 39 through the contact R of 5 and is supplied to the base of the transistor 290, thereby controlling the collector-emitter impedance of the transistor 29 and performing AGC of the recording signal. be exposed.

When recording an octopus, a bias signal is supplied from the oscillation circuit 34 to the head 33, and the switch 13 closes contact R.
By connecting K (at this time, switch 3 is connected to contact T
) The speaker 36 is turned off to prevent howling.

On the other hand, when receiving a broadcast, switches 1 to 3 are connected to contact B as shown in the figure, and switches 11 to 15 are also connected to contact P as shown in the figure.

Therefore, the detection signal from the tuner circuit 31 is transmitted to the switch 1.
Contact B → Amplifier 22 → Variable resistor 35 → Amplifier 25 →
is supplied to the speaker 36 through contact B of the switch 3,
Broadcast reception is performed.

6 indicates a low frequency boost switch, and when receiving a broadcast, when the switch is connected to the contact I as shown in the figure, the collector of the transistor 24 is connected to the contact P of the switch 14 → the contact B of the switch 2 → the switch The amplifier 22 is connected to the emitter of the transistor 23 through the contact L4 of the reproducing equalizer element 41 for negative feedback, and the amplifier 22 is used as a reproducing equalizer amplifier, that is, a low-frequency boosting amplifier.

Therefore, the sound reproduced from the speaker 36 is rich in bass.

Further, when receiving this broadcast, when the switch is connected to the contact F contrary to the diagram, the collector of the transistor 24 is connected to the transistor through the contact P of the switch 14 → contact B of the switch 2 → contact F of the switch 6 → the resistor 43. The amplifier 22 is connected to the emitter of the amplifier 23, and the amplifier 22 becomes a flat amplifier and does not enhance the bass.

Further, when recording a broadcast, switches 1 to 3 are connected to contact B as shown in the figure, and switches 11 to 15 are connected to contact R contrary to the figure.

Therefore, the detection signal from the tuner circuit 31 is transmitted to the switch 1.
The signal is supplied to the head 33 through the contact B of the amplifier 22, the contact R of the switch 15, the bias trap circuit 37, and the equalizer circuit 38, and the contents of the broadcast are recorded on tape.

At this time, the AGC of the recording signal is performed by the rectifier circuit 39 and the transistor 29, and the oscillation circuit 34
A bias signal is supplied to the head 33.

In this case, the collector of the transistor 24 is connected to the transistor 23 through the contact R of the switch 14 → the resistor 42.
The amplifier 22 is connected to a 7-band amplifier.

Furthermore, in this case, the signal from the amplifier 22 is supplied to the speaker 36 through the variable resistor 35→amplifier 25→contact B of the switch 3, so that the recorded content can be monitored.

Thus, according to the present invention, when receiving a broadcast, it is possible to enhance the low range of the reproduced sound, and it is possible to reproduce powerful sound.

Moreover, the configuration for this purpose is extremely simple and inexpensive since it is only necessary to add the switch 6.

Note that, for example, as shown in FIG. 2, it is also possible to enhance the low frequency range even when recording broadcasts.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram of one example of the present invention, and FIG. 2 is a partial connection diagram of another example of the present invention.

Claims (1)

[Scope of utility model registration request] A playback head, a playback equalizer amplifier that reproduces and equivalently amplifies the output signal of the playback head, a main amplifier that amplifies the output signal of the playback equalizer amplifier, a speaker to which the output signal of the main amplifier is supplied, and a tuner circuit. , a changeover switch, which supplies the output signal of the playback head and the output signal of the tuner circuit to first and second contacts of the changeover switch, and supplies the output signal of the changeover switch to the playback equalizer amplifier. When playing back a tape, the output signal of the playback head is supplied to the playback equalizer amplifier through the first contact of the changeover switch to perform playback equalization, and then supplied to the speaker through the main amplifier, and then broadcast. When receiving the radio tape, the output signal of the tuner circuit is supplied to the reproduction equalizer amplifier through the second contact of the changeover switch for reduction and amplification, and then supplied to the speaker through the main amplifier. recorder.