JPH03192402A - Integration circuit - Google Patents

Abstract

PURPOSE:To obtain a high-speed starting characteristic without being affected by the time constant of an integration circuit in the velocity control circuit of an FG motor, etc., by parallelly providing switches in a resistor so that the resistor can be switched to a through circuit. CONSTITUTION:In a CR integrator composed of an integrating resistor R and a capacitor C for integration, semiconductor switches SW such as mechanical or analog switches, etc., are provided and a delay circuit L is provided for opening/ closing these switches SW so that delay can be loaded only when the switches are turned OFF. Then, the through circuit is constituted so that the switches SW can be turned ON, the resistor R can be short-circuited and the input signal and output signal of the integration circuit can be made the same when a start signal, which is generated when the motor is turned ON, is turned ON. Thus, in the FG motor control circuit, etc., the starting/stopping characteristic of the motor can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an integrating circuit, and particularly to an improvement of an integrating circuit suitable for a control circuit for an FG motor.

[Summary of the Invention] In an integrating circuit, a switch is arranged in parallel to a resistor connected to an integrating capacitor or an integrating capacitor connected in parallel to an operational amplifier, so as to switch to a through circuit or a voltage follower circuit.

[Prior Art] FIG. 5 shows a conventional speed control circuit for an FG motor. In the same figure, 1 is the FG motor, 2 is the FG amplifier, and 3 is the F
A V (frequency-voltage) conversion circuit, 4 an integrating circuit, and 5 a motor driver. Speed control using the FG multiplied signal of the motor 1 involves amplifying the FG multiplied signal from the motor 1 with the amplifier 2, and then obtaining a DC voltage output (rotation speed signal) corresponding to the rotational speed of the motor 1 using the FV conversion circuit 3. This is done by

This output signal is input to the motor driver 5 as the rotation speed signal of the motor 1 via the integration circuit 4, and the motor driver 5 compares the reference voltage value and the rotation speed signal value, and controls the motor rotation so that this voltage difference becomes small. Control speed.

Generally, when comparing the voltages in the motor driver 5, if the rotation speed signal value is larger than the reference voltage value, the rotation speed of the motor 1 is increased, and conversely, when the rotation speed signal value is small, the rotation speed of the motor 1 is decreased. It has become. Therefore, in the FG method motor control, the rotation speed signal value of the motor driver is set to a value sufficiently larger than the reference voltage value at startup to force the motor 1 to rotate at high speed, and the initial FG from the motor is In addition to obtaining double the signal, it is possible to obtain high-speed start-up characteristics.

Figure 6 shows an FG using a CR integrator as a conventional integration circuit.
The waveforms of various parts when the motor control circuit is started are shown. Generally, in an FV conversion circuit, the minimum converted voltage value is output when the FG multiplied signal from the motor is not input, and on the contrary, the maximum converted voltage value is output at the time of startup. moreover,
When starting the motor, by forcibly setting the rotation speed signal value input to the motor driver higher than the reference voltage value, it is possible to obtain an initial FG times signal from the motor and to obtain high-speed starting characteristics. There is.

[Problem to be solved by the invention] However, in the conventional method, when the output signal of the FV conversion circuit as a starting signal suddenly rises, the integration circuit is inserted between the FV conversion circuit and the motor driver. The starting signal is integrated, and a delay of Δ occurs before the rotational speed signal value from the integrating circuit exceeds the reference voltage value connected to the motor driver. Therefore.

The larger the integral time constant is set to stabilize the motor's rotational speed, the slower the motor's starting characteristics become.

Similarly, FIG. 7 shows the starting characteristics of the FG motor when a non-inverting operational amplifier is used as the integrating circuit.

Conventionally, attempts have been made to set gain characteristics over a wide frequency band and obtain high-speed start-up characteristics by using a non-inverting operational amplifier as an integrating circuit. In this case, the output voltage of the integrating circuit when the motor is stopped is the minimum value of the operational amplifier, so in order for the starting signal voltage from the integrating circuit to exceed the reference voltage value of the motor driver, the output voltage must be higher than this reference voltage value. A starting signal for the FV conversion circuit is required to have a large amplitude. Therefore, if the amplitude of the output signal of the FV conversion circuit cannot be obtained sufficiently, the output of the integrating circuit will rise as shown in Figure 7, and the motor will continue to operate until this output voltage becomes larger than the reference voltage value of the motor driver. Since the motor did not start, it was not possible to obtain high-speed motor starting characteristics.

[Object of the Invention] Therefore, an object of the present invention is to provide an integrating circuit that can obtain high-speed starting characteristics without being affected by the time constant of the integrating circuit in a speed control circuit of an FG motor.

[Means for Solving the Problems] In order to achieve the above object, the first invention of the present application includes a resistor interposed in series between input and output, and a resistor interposed between one end of the resistor and ground. The gist of this invention is that in an integrating circuit consisting of a capacitor, a switch is arranged in parallel with the resistor, so that the circuit can be switched to a through circuit.

Further, the second invention of the present application is an integrating circuit using a non-inverting operational amplifier, in which a switch is arranged in parallel to a capacitor provided between the inverting input side and the output side of the operational amplifier, so that the circuit can be switched to a voltage follower circuit. The summary is what was done.

[Function] When the switch is turned on, the integrating circuit is switched to a through circuit or a voltage follower circuit, so that the starting and stopping characteristics of the motor can be improved in the FG motor control circuit or the like.

[Embodiments] The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment of a CR integrating circuit according to the first invention of the present application, which is suitable as an integrating circuit for the FG motor control circuit shown in FIG. In the figure, R is an integrating resistor, C is an integrating capacitor, SW is a start switch, and L is a delay circuit.

In the above CR integrator, a semiconductor switch SW such as a mechanical or analog switch is provided at both ends of the resistor R, and a delay circuit is provided for the opening and closing of this switch SW, so that a delay is applied only when the switch SW is turned OFF. There is. When the start signal generated when starting the motor is ON, the switch SW is turned ON and the resistance R is shorted, thereby setting the value of the integrating resistance of the integrating circuit to zero, and creating a through circuit in which the input signal and output signal of the integrating circuit are the same. I'm trying to make it happen. Note that the start signal is generated when the motor starts.

FIG. 2 shows signal waveforms at various parts of the circuit. FIG. 3 shows an embodiment of an integrating circuit suitable for the FG motor control circuit according to the second invention of the present application. In the same figure, the circuit components are the same or similar to those in FIG. It's an amplifier.

In the above integration circuit using the non-inverting operational amplifier AMP, a semiconductor switch SW such as a mechanical or analog switch is provided at the face end of the inverting input end and the output end of the operational amplifier, and when the motor is stopped, the capacitor C between the two is connected by the switch. The circuit is short-circuited, and the integration time constant of the integration circuit is temporarily set to zero, causing the integration circuit to operate as a mere voltage follower circuit.

Next, the operation of the above embodiment will be explained. In the CR integration circuit shown in Fig. 1, a switch SW is provided at both ends of the resistor R, and a delay circuit is used to switch the opening and closing of the switch SW from OFF to OFF.
A delay is applied only when N is activated. By short-circuiting the resistive end of the interval integrating circuit whose switch is ON when the motor is started, the time constant of the integrating circuit can be temporarily set to only the capacitance when the motor is started.

Therefore, assuming that the ON resistance of the switch SW is sufficiently small, the activation signal from the FV conversion circuit is directly transmitted to the motor driver without being integrated by the integrating circuit. As a result, a start signal that is sufficiently higher than the reference voltage value is applied to the motor driver at the same time that the start signal turns ON, and the rise characteristics of the motor rotation speed only depend on the motor and motor driver, resulting in a shorter delay time than before. Small and fast startup characteristics can be obtained. When the motor stops, the switch turns on at the same time as the star 1 signal turns off, so it is the same as if the stop signal from the FV conversion circuit was directly transmitted to the motor driver without going through the integration circuit. , it is possible to perform a high-speed stopping operation.

In the case of using the integrating circuit using the non-inverting operational amplifier AMP shown in Fig. 3, a switch SW is provided between the inverting input terminal and the output terminal of the operational amplifier, and by short-circuiting when the motor stops, storage is stored in the integrating capacitor C. At the same time, the integrated circuit is made to operate as a mere voltage follower circuit. As a result, the 8-power voltage value of the integrator when the motor is stopped is the same as the minimum value of the FV conversion circuit output, and when the start signal corresponding to the maximum output amplitude of the FV conversion circuit is input at startup, the integrator circuit instantly The output voltage of F increases by this amplitude voltage region, and the start signal always exceeds the reference voltage value of the motor driver.
The motor starting time can be shortened without being affected by the output amplitude value of the V conversion circuit. Furthermore, even when the motor is stopped, the stop signal is quickly set to the minimum voltage value by the output of the FV conversion circuit, so that a high-speed stopping operation can be performed. Similarly, since the charge in the integral capacitor C is discharged by the switch SW, the integral circuit output voltage is always quickly fixed at the minimum output value of the FV conversion circuit even if the motor starts or stops within a short period of time. It is possible to obtain constant starting characteristics at all times.

[Effects of the Invention] As explained above, according to the first invention of the present application, in the motor speed control circuit, it is possible to improve the start/stop characteristics of the motor without changing the integral time constant of the control system. . According to the second invention, in the motor speed control circuit, the motor starting characteristics are not affected by the maximum output amplitude level of the FV conversion circuit. In particular, the smaller the maximum output amplitude level, the greater the effect, and furthermore, when the motor starts and stops repeatedly within a short period of time due to forcibly discharging the charge in the integrating capacitor of the integrating circuit by opening and closing the switch. It is possible to always obtain constant starting characteristics even in the case of

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 is a waveform diagram for explaining its operation, Fig. 3 is a circuit diagram showing another embodiment of the present invention, and Fig. 4 is for explaining its operation. Waveform diagram, Figure 5 is FG
A block diagram showing the motor control circuit, FIGS. 6 and 7 are waveform diagrams showing starting characteristics of the FG motor corresponding to different integration circuits of the circuit shown in FIG. 5, respectively. R・・・・・・・・・ Integral resistance, C・・・・・・・・・
Integrating capacitor, SW...Start switch, L...Delay circuit, AMP...
...Non-inverting operational amplifier. CR Monthly 1 minute J reference figure 1 based on $Meji column

Claims (2)

[Claims] (1) An integrating circuit consisting of a resistor interposed in series between input and output, and a capacitor interposed between one end of the resistor and ground, characterized in that a switch is installed in parallel with the resistor. Integrating circuit. (2) An integrating circuit using a non-inverting operational amplifier, characterized in that a switch is arranged in parallel to a capacitor provided between the inverting input side and the output side of the operational amplifier.