JPS5818478Y2 - Motor control circuit - Google Patents

Description

[Detailed description of the invention] This invention relates to a motor control circuit, and its purpose is to provide a command shorter than the predetermined motor stop time (for example, when the stop time is 3 seconds, the command is less than 3 seconds). For commands), the determined motor stop time regardless of the length of the command, and for long commands (here, 3 seconds or more), the command time (for example, if a 5 second command is given, 5 seconds) An object of the present invention is to provide a motor control circuit that controls the rotation of the motor to stop.

Conventionally, when recording the proceedings of a meeting or the like, a method was used in which the proceedings were recorded on a tape recorder and then listened to again while writing down the proceedings, rather than writing them down on the spot.

However, even in such cases, the speed of speaking is much faster than the speed of writing, so the scribe must listen to the recording for a certain period of time, then stop the tape recorder, write down, and repeat this operation repeatedly. There must be.

The present invention aims to eliminate the above-mentioned complicated operations and to control the drive motor of a tape recorder so that the minutes can be recorded quickly and accurately while listening to them.

Hereinafter, one embodiment of the present invention will be explained with reference to FIGS. 1 to 4. In FIG. 1, 1 is a command switch, 2 and 3 are resistors, and 4 is a transistor. The state shown in is a non-conducting state.

5 is a capacitor, and this capacitor constitutes a differentiating circuit with resistor 3 and resistors 6 and 7.

Reference numeral 8 denotes a transistor, to whose base terminal a voltage divided by resistors 6 and 7 is applied, transistor 8 is in a conductive state, and current flows into its collector terminal through resistor 9.

10 is a charge storage capacitor, 11 is a diode, and this diode allows the charge of the capacitor 10 to be transferred to the transistor 8.
This prevents discharge from occurring through the

12 and 13 are resistors which determine the base current of the transistor 14 and the discharge time of the capacitor 10.

Transistor 14 is non-conducting and supplies current to the base terminal of transistor 16 through resistor 15, and this transistor is conducting and motor 17 rotates.

The diode 18 and the resistor 19 supply current to the base terminal of the transistor 14 only when the command switch 1 is pressed, making the transistor conductive.

The case where the command switch 1 is operated in the above state will be explained with reference to Fig. 2. In Fig. 2, the vertical axis represents voltage, the horizontal axis represents time, and the figure a indicates the command switch. 1 operation time.

In other words, this figure a means that the command switch 1 is pressed for a time t1.

At this time, transistor 4 becomes conductive, and is instantaneously differentiated by a differentiating circuit composed of capacitor 5 and resistors 6 and 7. Transistor 8 becomes non-conductive for this differentiated time, producing the waveform shown in Figure 2 a'. obtain.

That is, the collector terminal of the transistor 8 has a time t2,
A pulse whose peak value is power supply voltage element B is output.

The lever pulse charges the capacitor 10 and produces a voltage having the waveform shown in FIG.

That is, capacitor 10 is charged to power supply voltage B in time t2, and then discharged with a discharge time constant determined by capacitor 10 and resistor 13.13.

This discharge time is t3 shown in FIG.
stops for a time of t2+t3.

What has been described above is the case where the time t1 for pressing the command switch 1 is shorter than the discharging time of the capacitor 10.

Next, the case where the command switch 1 is pressed for a time longer than the discharge time will be explained with reference to FIG. 3. FIG. 3C shows the time t'1 during which the command switch 1 is pressed.

In this case as well, the differentiation is made by the differentiating circuit in the same way as above.
As shown in FIG. 3D, at time t2, a pulse whose peak value is the power supply voltage voltage B is output to the collector terminal of transistor 8, and capacitor 10 is charged by pulse time t2 as shown in FIG. Discharge occurs after time t3 with a discharge time constant determined by 17 maintains a stopped state.

Next, when the command switch 1 is released, that is, immediately after the time t2+t3+t4 after the command switch 1 is pressed, the motor 17 is released from the stopped state and starts rotating.

However, the capacitor 5 and the resistors 6 and 7 are configured so that the pulse time t2 shown in FIG. The constants of the differentiator circuit are determined.

Next, the fourth example shows the case where the constant of the differentiating circuit is changed to make the pulse time t2 shorter than the time constant for charging the capacitor 10.
To explain with reference to the figure, this figure 4 e is the time when the command switch 1 is pressed as in the case of figure 1, and the capacitor 10 is charged at time t5 as shown in figure 3 f. Since t5<t2, the discharge time t6 naturally becomes 16<13, and the motor 7 stops for the time t5+t6, which is shorter than the time t2+t3.

Next, when the command switch 1 is pressed twice in succession as shown in Fig. 4e, a pulse is output to the collector terminal of the transistor 8 at time t5 and the peak value of the power supply voltage terminal B is output to the switch 1 as shown in Fig. 4e'. Charging pressure when pressed once ■Higher than 1■
2, the capacitor 10 is charged.

As a result, the time t7 during which the charge in the capacitor 10 is discharged is naturally t7>t6, and the remoter 17 maintains the stopped state for the time t5+t5+17.

Further, if the command switch 1 is kept pressed, the motor 17 remains in a stopped state for the period of time the command switch 1 is kept pressed, similar to the explanation in FIG. 3 above.

The present invention can stop the motor 17 by changing the charging time by changing the capacitor 5 or 10 of the differential circuit with a changeover switch, or by changing the discharge time of the capacitor 10 by changing the resistor 12 with a changeover switch. You can make it possible to select the time, or you can replace the resistor 12 with a semi-fixed resistor so that the stop time of the motor 17 can be adjusted when configuring the circuit, or you can make the resistor 12 variable externally so that the motor 17 can be adjusted as desired. The stop time of 17 may be changed.

In addition, in the above embodiment of the present invention, a switch that closes when pressed is used as the command switch 1, but this switch is the fifth switch.
A changeover switch as shown in the figure may also be used.

In FIG. 5, reference numeral 21 denotes a changeover switch, and this changeover switch consists of a movable contact piece a and fixed contacts A and C.

A resistor 20 has one terminal connected to a power source B, and the other terminal connected to a fixed contact of a changeover switch 21 and a diode 18, respectively.

The movable contact piece a of the changeover switch 21 is connected to ground,
Fixed contact C is connected to capacitor 5.

In the circuit shown in FIG. 5, when the changeover switch 21 is operated to switch the movable contact a from the fixed contact to the C,
The grounding of the resistor 20 is released and current flows through the resistor 20 to the diode 18 .

Furthermore, when the fixed contact C is switched as described above, the voltage is differentiated by the differentiating circuit composed of the capacitor 5 and the resistors 6 and 7, and a voltage with a waveform similar to that shown in FIG. 2 a' is applied to the collector terminal of the transistor 8. The motor 17 is stopped by the same operation as above.

Note that the operation of this case conversion is the same as that explained with reference to FIGS. 2, 3, and 4, so the explanation thereof will be omitted.

The control circuit of the present invention can be used not only for controlling motors as described above, but also for controlling all electrically controllable items such as display devices using lamps, relays, magnetic buzzers, etc.

The effects of using the control circuit of the present invention for controlling the drive motor of a tape recorder are as follows.

In other words, if you want to write while listening to a recording recorded on a tape recorder, you do not have to perform the complicated operation of manually stopping the tape recorder repeatedly and writing during the stopping period, as in the past. With an extremely simple operation, you can stop the rotation of the tape recorder's drive motor for a certain period of time, stop the tape from running, and then automatically start running the tape, even when the motor needs to be stopped for a longer period of time. This stopped state can be maintained and it can be easily written while listening to the recording.

Furthermore, if the pulse generation time is made shorter than the charging time, the tape running stop time can be adjusted depending on the length or complexity of the content being listened to, which is very effective.

[Brief explanation of the drawing]

Figure 1 shows an example of the control circuit of the present invention, Figure 2 is a timing chart when the command switch is pressed for a relatively short time, Figure 3 is a timing chart when the command switch is pressed for a long time, and Figure 3 is a timing chart when the command switch is pressed for a long time. FIG. 4 is a timing chart when the output pulse of the differentiating circuit is made shorter than the charging time, and FIG. 5 is a detailed diagram of the changeover switch portion of another embodiment of the present invention. 1...Swin f, 2, 3, 4, 5, 6, 7, 8
．． 9...Circuit that generates impulses, 10...
... Condenser that accumulates electric charge, 13, 14, 1
5.16...Switching circuit.

Claims (1)

[Scope of utility model registration request] a circuit that generates an impulse when the switch is actuated;
A capacitor that accumulates charge due to this impulse and discharges when the impulse disappears, and the output voltage of the capacitor is applied to the input terminal, and when this input terminal voltage is above a predetermined value, the motor is stopped and the input voltage is below the predetermined value. A motor control circuit comprising: a switching circuit that drives the motor when the switch is in operation; and a bypass circuit that directly applies a voltage equal to or higher than the predetermined value to an input terminal of the switching circuit while the switch is in operation.