JPS634300Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording control circuit for a tape recorder, and will be described in detail below with reference to the illustrated embodiments.

In the illustrated circuit, 1 is an input terminal into which a recording signal from a radio receiving device or the like is input, 2 is a preamplifier circuit that amplifies the recording signal input to the input terminal 1, and 3 is the preamplifier circuit 2. It is an electronic volume that electronically adjusts the level of the signal amplified by the input terminal 4, the output terminal 5, and the control terminal 6.
It is equipped with 7 is a microphone amplifier circuit for amplifying the signal obtained from the microphone 8; 9;
is a variable resistor that adjusts the level of the output signal of the microphone amplifier circuit 7. 10 is a first electronic switch that controls the output of the signal whose level has been adjusted by the electronic volume 3, and includes an input terminal 11, an output terminal 12, and a control terminal connected to the output terminal 5 of the electronic volume 3. It is equipped with 13. A second electronic switch 14 controls the output of the signal whose level has been adjusted by the variable resistor 9, and includes an input terminal 15, an output terminal 16, and a control terminal 17. 18 is a recording amplifier circuit whose input terminal is connected to the output terminal 12 of the first electronic switch 10 and the output terminal 16 of the second electronic switch 14; 19 is a recording signal to which the recording signal from the recording amplifier circuit 18 is applied; 20 is a bias oscillation circuit that supplies a bias signal to the recording magnetic head 19. 21 is a clock pulse generation circuit that generates clock pulses; 22 is a frequency division circuit that divides the frequency of the pulse signal from the clock pulse generation circuit 21; 23 is an adjustment circuit that adjusts the division ratio of the frequency division circuit 22; and 24 is the above-mentioned circuit. AND circuit 2 into which the signal divided by the frequency dividing circuit 22 is input;
5 connects the input terminal 26 to the output terminal of the AND circuit 24.
is connected and the reset terminal 27 is low.
This is a counter circuit that performs a counting operation when it is at a (low) level. 28 is a manually operated and lock type control switch;
One terminal 28a is grounded and the other terminal 28b
is connected to the reset terminal 27 of the counter circuit 25 and to the power supply via a resistor 29. 30 is a D-A converter that converts the digital signal output from the counter circuit 25 into an analog signal, and its output terminal 31 is connected to the control terminal 6 to control the operation of the electronic volume 3.
It is connected to the. 32 is the counter circuit 2
5 is a control circuit that outputs an H (high) level switching signal when the count number reaches a predetermined number, and its output terminal 33 is connected to the above-mentioned signal via an inverter 34.
It is connected to the input terminal of the AND circuit 24. 3
Reference numeral 5 denotes a timer circuit which enters the operating state when an H level signal is output from the control circuit 32 and outputs an H level switching signal to its output terminal 36 after a set time; via the control terminal 13 of the first electronic switch 10 and the control terminal 1 of the second electronic switch 14.
7 is connected. 38 is a count value setting circuit for setting the count number at which the control signal is output from the control circuit 32, and 39 is a timer setting circuit for setting the timer time of the timer circuit 35. In such a circuit, the electronic volume 3 is configured such that the amount of attenuation increases as the level of the signal applied to the control terminal 6 increases, that is, the level of the signal output to the output terminal 5 decreases. . In addition, the first electronic switch 10 and the second
The electronic switch 14 is turned off when the signals applied to its control terminals 13 and 17 are at L level, and turned on when the signals are at H level.

As described above, the recording control circuit of the present invention is constructed, and its operation will be explained next. When the control switch 28 is in the open state shown, an H level signal is applied to the reset terminal 27 of the counter circuit 25 via the resistor 29, so the counter circuit 25 is in an inactive state. Further, since an L level signal is output to the output terminal 33 of the control circuit 32, the timer circuit 35 is in an inactive state. Therefore, the output terminal 36 of the timer circuit 35
Since an L level signal is being output to the first electronic switch 10 and the second electronic switch 14,
control terminals 13 and 17 have H level and L level, respectively.
With the level signal applied, the switches 10 and 14 are in the on and off states, respectively.
In such a state, when the user performs a recording operation, the tape recorder enters the recording operation state, and the recording signal applied to the input terminal 1 is amplified by the preamplifier circuit 2 and then sent to the input terminal 4 of the electronic volume 3. is applied to The recording signal applied to the input terminal 4 of the electronic volume 3 is level-adjusted by the electronic volume 3 whose attenuation amount is set by an adjustment means (not shown), and outputted to the output terminal 5. The recording signal output to the output terminal 5 is the first one in the on state.
The signal is input to the recording amplifier circuit 18 through the electronic switch 10 and amplified, and then applied together with a bias signal from the bias oscillation circuit 20 to the recording magnetic head 19 to be recorded on a magnetic tape. In such a recording state, a pulse signal is output from the output terminal of the AND circuit 24, but since the counter circuit 25 is in an inactive state, the pulse signal is not counted, and a count signal is output from its output terminal. Never. Further, since the second electronic switch 14 is in the off state, the recording signal from the microphone 8 is not applied to the recording amplifier circuit 18.

The recording operation is carried out as described above. Next, the operation when the control switch 28 is closed when the tape recorder is in the recording operation state will be described. When the control switch 28 is closed, the reset terminal 27 of the counter circuit 25 is connected to the switch 28.
Since the counter circuit 25 is grounded and becomes L level, the counter circuit 25, which has been in an inactive state, becomes in a counting operating state. When the counter circuit 25 starts counting, a digital signal corresponding to the count is output from its output terminal. The digital signal which is the output signal of the counter circuit 25 is converted into an analog signal by the DA converter 30 and applied to the control terminal 6 of the electronic volume 3. Since the level of the analog signal applied to the control terminal 6 of the electronic volume 3 gradually increases as the number of pulse signals counted by the counter circuit 25 increases, the amount of attenuation by the electronic volume 3 gradually increases. . As a result, the level of the recording signal output to the output terminal 5 of the electronic volume 3 gradually decreases. and the counter circuit 2
When the count number 5 reaches the value set by the count value setting circuit 38, the control circuit 32 outputs an H level control signal to its output terminal 33.
When the control circuit 32 outputs an H level signal, one input signal of the AND circuit 24 becomes L level, so that the pulse signal input to the counter circuit 25 disappears. Therefore, the counter circuit 25
The count number will not increase any further,
The level reduction of the recording signal by the electronic volume 3 is stopped. Further, when the control circuit 32 outputs an H level signal, the timer circuit 35 becomes operational, and when the time set by the timer setting circuit 39 has elapsed, an H level switching signal is output to the output terminal 36. . When the timer circuit 35 outputs an H level signal, the levels of the signals applied to the control terminal 13 of the first electronic switch 10 and the control terminal 17 of the second electronic switch 14 are inverted to L level and H level, respectively. Therefore, the first electronic switch 10 and the second electronic switch 14 are turned off and on, respectively. Therefore, the input of the recording signal input from the input terminal 1 to the recording amplifier circuit 18 is cut off, and the recording signal from the microphone 8 is transmitted to the microphone amplifier circuit 7-variable resistor 9.
- It is input to the recording amplifier circuit 18 through the second electronic switch 14. The recording signal from the microphone 8 input to the recording amplifier circuit 18 is amplified and then applied to the recording magnetic head 19 to be recorded on a magnetic tape. As described above, when the control switch 28 is switched while the tape recorder is in the recording operation state, the level of the recording signal input to the input terminal 1 that is input to the recording amplifier circuit 18 gradually decreases, and the level is set. When the value is reached,
Recording is continued at that level for a predetermined time, and after a predetermined time elapses, the recording signal from the input terminal 1 is cut off, and the recording signal obtained from the microphone 8 is input to the recording amplifier circuit 18 and becomes ready to be recorded. .

When the control switch 28 is opened in such a state, an H level signal is applied to the reset terminal 27 of the counter circuit 25, so that the counter circuit 25 is reset to the initial state. When the counter circuit 25 is reset, its output becomes the initial state, so that the control terminal 6 of the electronic volume 3
The signal applied to the electronic volume 3 disappears, and the electronic volume 3
returns to its original state. Furthermore, since the output of the control circuit 32 is inverted to L level, the level of the signal output to the output terminal 36 of the timer circuit 35 is inverted to L level. As a result, the first electronic switch 10, which was in the off state, is turned on, and the second electronic switch 14, which was in the on state, is reversed to the off state. Therefore, the recording signal from the microphone 8 is cut off, and the recording signal input to the input terminal 1 is input to the recording amplifier circuit 18 at the original level and is recorded.

In such a circuit, by changing the setting value of the count value setting circuit 38, the level reduction amount of the recording signal by the electronic volume 3 can be set arbitrarily,
By varying the frequency division ratio of the frequency dividing circuit 22 using the adjustment circuit 23, the speed at which the level of the recording signal by the electronic volume 3 decreases can be freely varied. In addition, by changing the timer setting time of the timer circuit 35 using the timer setting circuit 39, it is possible to freely select the time from when the level of the recording signal drops to a predetermined value until the recording signal input to the recording amplifier circuit 18 is switched. I can do it. and a means for switching the recording signal inputted from the input terminal 1 and a microphone 8.
Although the case has been described in which an electronic switch is used as a means for switching the recording signal from the receiver, a relay or the like may also be used. Furthermore, in this explanation, one recording signal is a signal obtained from a radio receiving device, and the other recording signal is a signal obtained from a microphone. etc. can also be used as a recording signal.

As explained above, in the recording control circuit of the present invention, when the control switch is switched while the tape recorder is in the recording mode, the level of the recording signal being recorded is gradually lowered, and then the level of the recording signal is lowered for a predetermined period of time. Recording is performed at the reduced level, the input of the recording signal to the recording amplifier circuit is cut off, and the recording signal from a recording signal input system different from the recording signal is guided to the recording amplifier circuit. Not only is it extremely convenient when editing signals or adding explanations to signals recorded on magnetic tape, but by increasing the amount of level reduction of the recorded signal using the electronic volume, it is possible to remove a predetermined period of no signal from the magnetic tape. If implemented in a tape recorder configured to control the operation of the tape recorder by detecting the no-signal portion, great effects will be produced.

[Brief explanation of the drawing]

The illustrated circuit is one embodiment of the recording control circuit of the present invention. Explanation of main drawing numbers, 2... Preamplifier circuit, 3...
Electronic volume, 7... Microphone amplifier circuit, 8... Microphone, 10... First electronic switch, 14... Second electronic switch, 18... Recording amplifier circuit, 19... Recording magnetic head, 21
... Pulse signal generation circuit, 22 ... Frequency division circuit, 2
5... Counter circuit, 28... Control switch,
30...D-A converter, 32...Control circuit, 35
...Timer circuit, 38...Count value setting circuit, 39...Timer setting circuit.

Claims (1)

[Scope of utility model registration request] A tape recorder comprising a first recording signal input system circuit into which a recording signal from a radio receiving device or the like is input, and a second recording signal input system circuit into which a recording signal different from the first recording signal input system circuit is input. , a clock pulse generation circuit that generates clock pulses, a frequency division circuit that divides the frequency of the pulse signal from the clock pulse generation circuit, a control switch that is manually switched, and when the control switch is switched, it enters a counting operation state and the A counter circuit that counts pulse signals from the circuit, a D-A converter that converts the digital signal output from the counter circuit into an analog signal, and is controlled by the analog signal from the D-A converter. and an electronic volume that adjusts the level of the recording signal from the first recording signal input system circuit;
a recording amplifier circuit to which a recording magnetic head is connected as a load; a control circuit that outputs a control signal when the count number of the counter circuit reaches a set value and blocks input of a pulse signal to the counter circuit; A timer circuit that enters the operating state when a control signal is output from the control circuit and outputs a switching signal after a set time; and a timer circuit that operates in reverse when the switching signal is output from the timer circuit to switch the recording signal from the electronic volume to the above state. a first switching means for cutting off input to the recording amplifier circuit; and when a switching signal is output from the timer circuit, a reversal operation is performed to guide the recording signal from the second recording signal input system circuit to the recording amplifier circuit. A recording control circuit for a tape recorder comprising a second switching means.