JPH0215930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape recorder, and more particularly to improvements in its voice operator circuit.

As is well known, the voice operator circuit in a tape recorder runs the tape and records data only when a signal is received during recording.

Conventionally, such voice operator circuits have generally been configured to rectify the output from the recording amplifier to drive the plunger, so they are often prone to malfunctions, and are complicated and large. It has the disadvantage that it tends to become

Therefore, the present invention has been made in view of the above points, and an object of the present invention is to provide an improved voice operator circuit that has a simple structure, can be made compact, and can always operate well. .

An embodiment of the present invention will be described in detail below with reference to the drawings.

That is, in FIG. 1, 11 is a recording signal detection section, and the base of the first stage transistor Q ₁ whose collector is connected to the power supply line L ₁ via series resistors R ₁ and R ₂ and whose emitter is grounded is a recording signal detection section. A recording signal is applied from the output end of the amplifier A through a capacitor _C1 and a resistor _R3 in series. Here, the base of the transistor Q ₁ is grounded through series resistors R _{a and} R _b that constitute the sensitivity switching circuit 12, and is connected to the power supply line ₁ through the same resistor R _c .
is connected to the midpoint between a resistor R _d and a diode D ₀ connected in series between and ground.

Further, the base of the second stage transistor Q ₂ included in the recording signal detection section 11 is connected to the series resistor.
It is connected to the midpoint of R ₁ and R ₂ , its emitter is connected to the power supply line L ₁ , and its collector is grounded via series resistors R ₄ and R ₅ . Similarly,
The third stage transistor _Q3 has its base connected to the midpoint of the series resistors _R4 and _R5 , its emitter grounded, and its collector connected to the power supply line _L1 via a resistor _{R6 and} a capacitor. Grounded via _C2 . Similarly, the fourth stage transistor
Q ₄ has its base connected to the output terminal of the time constant circuit TC consisting of the above-mentioned resistor R ₆ and capacitor C ₂ , its emitter is grounded, and its collector is connected to the power supply line via series resistors R ₇ and R ₈ . Connected to _L1 . Similarly, the fifth stage transistor _Q5 has its base connected to the midpoint of the series resistors _R7 and _R8 , its emitter connected to the power supply line _L1 , and its collector connected to the output of the recording signal detection section 11. The terminal is connected to the base of a transistor _Q6 , which serves as an input terminal of a motor governor circuit 13, which will be described later.

Here, the motor governor circuit 13 is configured as a bridge control type electronic governor, and the transistor Q ₆ has its base connected to the ground line L 2 via the resistor R ₉ and its emitter directly connected to the ground line L ₂ .
Furthermore, its collector is connected to the power supply line through resistor _R10 .
It is connected to L ₃ and to the base of transistor Q ₇ . This transistor Q ₇ has its emitter connected directly to the ground line L ₂ and its collector connected via corresponding resistors R ₁₁ and R ₁₂ to the respective fixed contacts of the speed changeover switch S _1a . This speed selector switch S _1a
has its common contact connected to the base of the transistor _Q8 through the diode _D1 and the resistor
Connected to power line L ₃ via R ₁₃ and R ₁₄ in series,
Furthermore, it is connected to one fixed contact of a playback speed changeover switch _S2a via a resistor _R15 .

The base of the transistor Q ₈ is connected to the capacitor C ₃ and the emitter of the transistor Q 8 is directly connected to the common contacts of the speed changeover switches R _1b and S _1c , and its collector is connected to the transistor Q 8 . Connected to the base of ₆ . The base of the transistor _Q8 is connected to the collector of the transistor _Q7 and one end of the motor M via a resistor _R16 , and the emitter thereof is connected to the other end of the motor M.

In the above, each fixed contact of the speed changeover switch S _1b is connected to the power supply line L 3 via the resistor R ₁₇ and R ₁₈ correspondingly, and each fixed contact of the speed changeover switch S _1c is connected to the power supply line L ₃ through the resistance R 17 and R 18 respectively. ₁₉ and _R20 correspondingly to the other fixed contact of the reproduction speed changeover switch _S2a . Moreover, the connection midpoint of the series resistors R ₁₃ and R ₁₄ is connected to the power supply line L ₃ via the heat-sensitive resistance element R ₂₁ .

In the figure, _S2b is a sensitivity changeover switch, one of whose fixed contacts is an idle contact, whose common contact is grounded, and whose other fixed contact and intermediate contact between the fixed contact and the common contact are They are respectively connected to the midpoint between series resistors Ra and Rb in the sensitivity switching circuit 12 and to the base of the fourth stage transistor Q ₄ in the recording signal detection section 11 .

The common contact of the playback speed changeover switch _S2a is connected to the playback side contact of the recording and playback changeover switch _S3 , and the intermediate contact between the common contact and the fixed contact is an idle contact.

Here, the recording/playback switch _S3 has its recording side contact connected to the power supply line _L1 and the emitter of a transistor _Q9 in the display circuit 14, which will be described later, and its common contact is connected to the power supply line _L3.
It is also connected to the emitter of a transistor _Q10 and a power supply +B in a display circuit 14, which will be described later.

The transistor Q ₉ constituting the display circuit 14 has its base connected to the collector of the first stage transistor Q ₁ in the recording signal detection section 11 via the resistor R ₂₂ and its emitter connected to the resistor R ₂₃ .
It is connected to the base of the same transistor Q10 via the transistor _Q10 , and its collector is further connected to the anode of the light emitting diode _LED1 , which serves as a display element. Also, the same transistor Q ₁₀ has a resistor R ₂₄ at its base.
It is connected to the power supply +B via the power source +B, and its collector is connected to the anode of a light emitting diode LED ₂ which serves as a display element. Here, both light emitting diodes
The cathodes of LED ₁ and LED ₂ are commonly connected to the play side contact of pause switch S ₄ via resistor R ₂₄ and also to the ground line L ₂ . Also,
The pause switch _S4 has its common contact grounded and its pause side contact serving as a contact.

In the above configuration, when recording when the recording/playback switch _S3 is set to the recording side contact, the power supply voltage from the power supply +B is supplied to the power supply line _L1 , so that the recording signal detection section 11 and the sensitivity are The switching circuit 12 becomes energized.

In such a state, when the output signal from the recording amplifier A is not input, the first stage transistor _Q1 of the recording signal detection section 11 is turned off. As a result, the second and third stage transistors Q ₂ and Q ₃
is turned off, so the capacitor of the time constant circuit TC
After a predetermined time period in which C ₂ is almost completely charged through resistor R ₆ , the fourth stage transistor Q ₄ is turned on.
Then, the transistors Q ₆ and Q ₇ of the motor governor circuit 13 are turned off via the fifth stage transistor Q ₅ which is turned on, so that the power supply to the motor M is blocked. In other words, the tape running is stopped.

In this situation, recording amplifier A
When an output signal as shown in FIG. 2a is input from the recording signal detecting section 11, the first stage transistor _Q1 and the second stage transistor _Q2 pulse-amplify the recording signal in so-called class C operation. A square wave signal as shown in FIG. 2b is introduced into the base of the second transistor _Q3 . As a result, the third stage transistor _Q3 will repeatedly turn on and off, so
The time constant circuit TC repeats a charging/discharging operation as shown in FIG. 2c, in which it is discharged before being almost completely charged. For this reason, the fourth and fifth stage transistors Q ₄ and Q ₅ are turned off during the period when the recording signal is input, so that the motor governor circuit 13 performs normal bridge control as controlled by the transistor Q ₈ . Works as a shaped electronic governor. As a result, the motor M becomes energized and is driven at a constant speed as shown in FIG. 2d. In other words, as soon as a recording signal is input, the tape is run at a constant speed to enable recording.

In this case, the motor governor circuit 13 is controlled by speed changeover switches S _1a , S _1b , and S _1c (assumed to be in an interlocking relationship), for example, in the case of a microcassette tape recorder, one fixed contact
It is possible to switch between two speeds, giving a constant speed of 1.2 cm/sec, and using the other fixed contact to give a double speed of 2.4 cm/sec.

Furthermore, if the recording signal no longer enters in such a state, it goes without saying that the tape running will be stopped again after a predetermined period of time from that point in the same way as described above.

In this way, it is possible to realize a voice operator circuit which can be simplified in structure and miniaturized without using a plunger as in the prior art, and which can always operate satisfactorily.

Next, the function of the sensitivity switching circuit 12 will be explained. This is to set the signal level for running the tape when a recording signal is input in the operation of the voice operator circuit as described above.

That is, the sensitivity selector switch _S2b is set at the intermediate contact-common contact position as shown in the figure, so that the output terminal (corresponding to the base of _Q4 ) of the time constant circuit TC in the recording signal detection section 11 is set at the ground level. Voice operator becomes inactive [OFF] state.
Further, at the set position of one of the fixed contacts and the common contact of the switch _S2b , the voice operator operates in a low sensitivity [LOW] state in which the midpoint of the series resistors Ra and Rb in the sensitivity switching circuit 12 is brought to the ground level. Furthermore, the _above series resistance Ra,
The voice operator operates in a high-sensitivity [HIGH] state in which the midpoint of Rb is released from the ground level.

By the way, in this case, the sensitivity selection switch S _2b is interlocked with the playback speed selection switch S _2a , so that both of these switches, which should originally be provided independently, can be used as one switch. It is characterized by its presence.

That is, during playback, the recording/playback switch _S3 is set to the playback side contact, and there is no need to perform the voice operator function, and both the above switches _S2a and _S2b are set to the playback side contact.
This is because there is no problem in making it an interlocking relationship. Of course, this does not pose any problem since there is no need to operate the playback system even when performing the voice operator function during recording as described above. In other words, if both switches were provided independently, one of them would be idle during recording and playback, which would be wasteful. By linking both switches, it is possible to eliminate waste and reduce space factor. It can be said that it is a win-win in that it can improve the size and contribute to further miniaturization.

Then, the playback speed selection switch S _2a
At the time of regeneration, the intermediate contact-common contact is in the set position as shown in the figure, and takes the [NORMAL] state which has no relation to the motor governor circuit 13, that is, provides constant speed running as described above only by the motor governor circuit 13. Also, the same switch S _2a
At the setting position of one fixed contact - common contact or the other fixed contact - common contact, the voltage from the power supply +B is related to the resistor R ₁₉ , R ₂₀ part or the resistor R ₁₅ part in the motor governor circuit 13, for example, the above [ -10% or + of NORMAL] condition
It takes the [SLOW] state for slow listening playback or the [FAST] state for fast listening playback, which gives a tape running speed of 10%.

In addition, both switches S _2a , which are in the above interlocking relationship,
Both S _2b are provided with a movable contact at an intermediate position between a common contact and a fixed contact, and are realized by, for example, a so-called 2C3P type slide switch.

Next, the display circuit 14 attached to the voice operator circuit as described above will be explained.
This is characterized in that the recording signal detection section 11 described above is used to function as a signal indicator during recording, and the indicator is turned off during pause to display the pause state.

That is, even with the output of the first stage transistor Q1 of the recording signal detection section ₁₁ that amplifies (detects) the output from the recording amplifier A during recording as described above,
By lighting the light emitting diode LED _1, which serves as a display element, through the transistor _Q9 of the display circuit 14 with an amount of light emitted according to the signal strength, it can function as a signal indicator during recording. Of course, even during recording, if no recording signal is received and tape running is stopped, the indicator is also off. In this case, by appropriately setting the operating level of the transistor _Q9 , it may be turned on and off to cause the light emitting diode LED ₁ to blink, thereby simply indicating that the recording state is in progress.

By the way, the above explanation is based on the pause switch for convenience.
The explanation has been made on the assumption that S ₄ is at the play side contact, but when the pause state is reached either during recording or playback, a pause operator (not shown) is used to temporarily stop motor M. The pause switch _S4 is also set as a pause side contact.

In other words, when pause switch S ₄ is set to the pause side contact, light emitting diode LED ₁ (described later)
The same applies to LED ₂ ), which is turned off when its cathode side is open. In this case, the ground line _L2 of the motor governor circuit 13 is also opened, so
The motor M becomes de-energized and is temporarily stopped.

Furthermore, the transistor Q ₁₀ in the display circuit 14
and light emitting diode LED ₂ are connected to the power supply + during playback.
This shows whether the B voltage is appropriate.
It functions as a so-called battery checker (turns off when the battery is depleted) when the battery is used.

In addition, in the case where the display circuit 14 is not provided in the above, the grounding line _L2 of the motor governor circuit 13 may be directly grounded.

Therefore, as described in detail above, according to the present invention, it is possible to provide an improved voice operator circuit which can be simplified in structure and miniaturized, and which can always operate satisfactorily.

[Brief explanation of drawings]

FIG. 1 is a wiring diagram showing an embodiment of the voice operator circuit according to the present invention, and FIG. 2 is a waveform diagram of each part for explaining the operation of FIG. 1. 11... Recording signal detection section, 12... Sensitivity switching circuit, 13... Motor governor circuit, 14... Display circuit.

Claims (1)

[Claims] 1. A recording signal detection section that controls switching of a time constant circuit between two states, i.e., repeatedly charging and discharging below a predetermined level or charging up to a predetermined level, depending on the presence or absence of a recording signal; a motor governor circuit that switches and controls a tape drive motor to run at a constant speed or a stopped state; a sensitivity changeover switch that switches the detection sensitivity of the recording signal in the recording signal detection section to three states: off, low, and high; and a playback speed changeover switch that is interlocked with the switch and switches the playback speed of the tape drive motor by the motor governor circuit into three states: normal, slow, and fast, so that both of the switches can be used simultaneously. The tape is immediately run at a constant speed when the recording signal corresponding to a predetermined sensitivity by the sensitivity changeover switch is input, and the tape is run at a constant speed after a predetermined time determined by the time constant circuit has passed when no recording signal is input. A voice operator circuit characterized in that it is configured to stop.