JPS596558Y2 - tape recorder with radio - Google Patents

Description

[Detailed description of the invention] This invention is a tape recorder with a radio that enables mixing and recording of signals from a microphone and signals from a radio using an amplifier equipped with an ALC circuit, and is equipped with a microphone ON/OFF switch that can be switched independently. At the time of mixing and recording, the microphone was turned on. When the OFF switch is changed from ON to OFF, that is, when the signal from the microphone is cut off and only the signal from the radio is recorded, the AL signal is the combined signal of the microphone signal and radio signal.
Since the C circuit was active, the capacitor that determines the time constant in the ALC circuit was charged to a high level, so the level of the radio recording dropped when this switch was made, and the volume decreased for a while. The purpose is to improve the drawback of storage.

The circuit of the tape recorder of the present invention shown in FIG. 1 will be explained below.

The parts indicated by thick lines in the figure are the features of this invention.
Other circuit configurations are common in tape recorders with built-in microphones and radios.

In other words, 1 is the built-in microphone, and the microphone ON-OF
ON by F switch 2. It will be turned off.

3 is a radio tuner, which is turned on and off by a radio/tape changeover switch 4;

In the illustrated state, the signal from the microphone 1 and the signal from the radio 3 are mixed at the recording/playback selector switch 5, passed through the recording amplifier 6 and the main amplifier 7, and then mixed and recorded by the recording/playback head 8. state, and part of the mixing signal is passed through diode 9 to capacitor 10.
is charged to control the base of the ALC transistor 11.

In the figure, switches that operate in conjunction with the radio/tape changeover switch 4 are indicated by terminals T and R, and switches that operate in conjunction with the recording and playback changeover switch 5 are indicated by terminals R and P.

12 is an external input jack, 13 is a bias oscillator, 14
1 is an erasing head, and 15 is a speaker.

As mentioned above, the features of the present invention are shown in the bold line in the figure, and 16 is a shorting type switch that works with the microphone ON/OFF switch 2.
The switch 16 is connected across the capacitor 10 of the ALC circuit.

Here, the relationship between the microphone ON-OFF switch 2 and the shorting type switch 16 will be explained based on FIG. 2.

Switch 2 has terminals A, B, and C, and switch 16
is equipped with terminals D and E, and the movable piece 2' of switch 2
When the movable piece 16' of the switch 16 is in contact between the terminals A and B, the movable piece 16' of the switch 16 is separated from the terminals D and E, and when the movable piece 2' of the switch 2 is switched between the terminals B and C. On the way, the switch 16 has its movable piece 16' connected to the terminal D.
, E are momentarily shorted, and then they are separated from terminals D and E.

Therefore, if the microphone ON-OFF switch 2 is switched from ON to OFF during mixing recording of the microphone and radio shown in FIG. 1, the signal from the microphone is cut off and only the signal from the radio is recorded. At this time, the shorting type switch 16 instantaneously shorts the capacitor 10 of the ALC circuit, and the high level charge that had been charged in the capacitor 10 until now is forcibly discharged. Transistor 11 becomes inactive.

Thereafter, the capacitor 10 is charged only by the radio signal, the ALC transistor 11 is activated, and the signal is quickly restored to the original radio recording level.

Therefore, if you are recording a mixture of the microphone signal and the radio signal and turn off the microphone ON-OFF switch to record only the radio signal, the ALC signal will be activated by the combined signal for a short period of time. This eliminates the drawback that the circuit activates and lowers the level of radio recordings.

In this embodiment, the capacitor that determines the time constant of the ALC circuit is directly short-circuited and discharged using a shorting type switch, or a variable resistor or the like is inserted in between to adjust the discharge time of the capacitor. You can also do that.

As described above, according to the tape recorder with radio of the present invention, when microphone and radio signals are mixed and recorded by an amplifier equipped with an ALC circuit, when the microphone ON-OFF switch is turned OFF, the ALC Since the circuit can be put into a momentary inoperative state, the level of radio recording will not drop due to undesired operation of the ALC circuit, and normal recording can continue. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a tape recorder with a radio according to the present invention, and FIG. 2 is a diagram showing the relationship between a microphone ON-OFF switch and a shorting type switch. 1...Microphone, 3...Radio tuner,
2... Microphone ON-OFF switch, 6... Recording amplifier, 10... ALC circuit capacitor, 11...
・ALC transistor, 16...Shorting type switch.

Claims (2)

[Scope of utility model registration request] (1) In a tape recorder with a radio, which is capable of mixing and recording a signal from a microphone and a signal from a radio using an amplifier equipped with an ALC circuit, and is equipped with an independently switchable microphone ON-OFF switch, the microphone ON-OFF switch can be switched independently. A shorting type switch that is interlocked with an OFF switch is provided in the ALC circuit, and when the microphone ON-OFF switch is changed during mixing and recording, the shorting type switch that is interlocked with the microphone ON-OFF switch momentarily puts the ALC circuit in an inactive state. A tape recorder with a radio. (2) The shorting type switch is an ALC
Utility model registration claim 1 characterized in that the capacitor that determines the time constant of the circuit is connected to momentarily short-circuit it.
Tape recorder with radio as described in section