JPS634297Y2 - - 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 figure, 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 an electronic volume that electronically adjusts the level of the signal amplified by the preamplifier circuit 2, and is provided with an input terminal 4, an output terminal 5, and a control terminal 6. 7 is a microphone amplifier circuit for amplifying the signal obtained from the microphone 8, and 9 is a variable resistor for adjusting 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. 14
is a second electronic switch that controls the output of the signal whose level has been adjusted by the variable resistor 9;
It has 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 amplifier circuit to which a recording signal from the recording amplifier circuit 18 is applied; 20 is a bias generating 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 frequency division ratio of the frequency divider circuit 22; 24 is an AND circuit to which the signal divided by the frequency divider circuit 22 is input; and 25 is an input terminal to the output terminal of the AND circuit 24. This counter circuit performs a counting operation when the terminal 26 is connected and the reset terminal 27 is at L (low) level. Reference numeral 28 denotes a manually operated and lock type control switch, with 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. 3
0 is a DA converter that converts the digital signal output from the counter circuit 25 into an analog signal, and its output terminal is connected to the control terminal 6 to control the operation of the electronic volume 3. 3
Reference numeral 1 denotes a control circuit that outputs an H (high) level switching signal when the count number of the counter circuit 25 reaches a predetermined value, and its output terminal 32 is connected to the control terminal of the first electronic switch 10 via an inverter 33. 13 and the control terminal 17 of the second electronic switch 14, and the inverter 34.
It is connected to the input terminal of the AND circuit 24. 3
Reference numeral 5 denotes a setting circuit for setting the count number at which the switching signal is output from the control circuit 31. In such a circuit, the electronic volume 3 is configured such that as the signal applied to the control terminal 6 becomes larger, the amount of attenuation becomes larger, that is, the level of the signal outputted to the output terminal 5 becomes smaller. Also the first
The electronic switch 10 and the second electronic switch 14 are
The signal applied to the control terminals 13 and 17 is L
When it is at the high level, it is in the off state, and conversely, when it is at the high level, it is in the on state.

The present invention is constructed as described above, 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, so the counter circuit 25 is in an inactive state. Further, since an L level signal is output to the output terminal 32 of the control circuit 31, the control terminal 1 of the first electronic switch 10 and the second electronic switch 14
3 and 17 are in a state where H level and L level signals are applied, respectively, and are in an on and off state, 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 controlled by the electronic volume 3 whose attenuation amount is set by an adjustment means (not shown).
The level of the signal is adjusted by , and the signal is output to the output terminal 5. The recording signal outputted to the output terminal 5 is input to the recording amplifier circuit 18 through the first electronic switch 10 which is in the on state, where it is amplified and then sent to the recording magnetic head 19 together with the bias signal from the bias oscillation circuit 20. is applied and recorded on magnetic tape. In such a recording operation 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. It is never output. Also,
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 performed as described above. Next, a case will be described in which the control switch 28 is closed when the tape recorder is in the recording operation state. When the control switch 28 is closed, the reset terminal 27 of the counter circuit 25 is grounded by the switch 28 and becomes L level, so that 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 counter circuit 25
The digital signal which is the output signal of
0 is converted into an analog signal 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 caused by the electronic volume 3 gradually increases. Become. As a result, the level of the recording signal output to the output terminal 5 of the electronic volume 3 gradually decreases. When the count number of the counter circuit 25 reaches the value set by the setting circuit 35, the control circuit 31 outputs an H level signal, which is a switching signal, to its output terminal 32. When an H level signal is output from the control circuit 31,
Since one input signal of the AND circuit 24 becomes L level, the pulse signal input to the counter circuit 25 disappears. Therefore, the count number of the counter circuit 25 does not increase any further, and the level reduction of the recording signal by the electronic volume 3 stops. Further, when the control circuit 31 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 become L level and H level, respectively. Due to the reversal, the first electronic switch 10 and the second electronic switch 14 are in an off state and an on state, respectively. Therefore, the input operation 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 input to the microphone amplifier circuit 7 - variable resistor 9 -.
Recording amplifier circuit 1 through second electronic switch 14
8 is input. 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 reaches this value, 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 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 signal applied to the control terminal 6 of the electronic volume 3 disappears, and the electronic volume 3 returns to its original state. Further, since the output of the control circuit 31 is inverted to the L level, 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 inverted 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 setting circuit 35, the level reduction amount of the recording signal by the electronic volume 3 can be set arbitrarily, and the frequency division ratio of the frequency dividing circuit 22 can be varied by the adjustment circuit 23. In this way, the speed at which the level of the recording signal is lowered by the electronic volume 3 can be freely varied. Also, input terminal 1
Although the case has been described in which an electronic switch is used as a means for switching the recording signal input from the microphone 8 and a means for switching the recording signal from the microphone 8, a relay or the like may also be used. Furthermore, in this explanation, one recording signal was assumed to be a signal obtained from a radio receiving device, and the other recording signal was assumed to be a signal from a microphone, but it is also possible to record a signal from another tape recorder or signals from two microphones. It can also be used as a signal.

As explained above, the recording control circuit of the present invention, when the control switch is changed while the tape recorder is in the recording operation state, gradually reduces the level of the recording signal being recorded, and then outputs the recorded signal. In addition to cutting off the input to the recording amplifier circuit, the recording signal from the recording signal input system different from the recording signal is guided to the recording amplifier circuit, so that it is possible to edit the recording signal or the signal recorded on the magnetic tape. This is extremely convenient when adding explanations, etc.

[Brief explanation of the drawing]

The illustrated circuit is one embodiment of the recording control circuit of the present invention. Explanation of main figure numbers, 3...Electronic volume, 8...
Microphone, 10...First electronic switch, 1
4... Second electronic switch, 18... Recording amplifier circuit, 19... Recording magnetic head, 21... Clock pulse generation circuit, 22... Frequency dividing circuit, 25...
Counter circuit, 28... Control switch, 30...
...D-A converter, 31...control circuit, 35...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 switching signal when the count of the counter circuit reaches a set value, and an inversion operation when the switching signal is output from the control circuit. and a first switching means for cutting off input of the recording signal from the electronic volume to the recording amplifier circuit;
a second switching means that performs an inverting operation when a switching signal is output from the control circuit and guides the recording signal from the second recording signal input system circuit to the recording amplifier circuit; After the level of the recording signal from the first recording signal input system circuit is gradually lowered, the input to the recording amplifier circuit is cut off, and the recording signal from the second recording signal input system circuit is guided to the recording amplifier circuit. A recording control circuit for a tape recorder characterized by: