JPH031824Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an automatic balancing instrument that performs recording by automatically balancing a recording head.

[Conventional technology]

In addition to AC motors, there are DC motors as motors used in automatic balancing instruments.

This type of automatic balance meter compares the deviation between the input signal of the input terminal 1 and the feedback signal of the sliding resistor 2 using a deviation amplifier 3, as shown in FIG. , R2, power supply +
The voltage is supplied to a drive circuit 4 consisting of V and -V to drive a DC motor 5. In other words, transistors Tr1 and TR2 are
is turned on, causing the DC motor 5 to rotate forward,
It is driven in reverse. This rotation of the DC motor 5 moves the brush of the sliding resistor 2, and when the feedback signal matches the magnitude of the input signal and the deviation is zero, the DC motor 5 automatically balances and stops. Further, the recording head 6 is linked to the DC motor 5, and recording is performed at a scale position corresponding to the magnitude of the input signal.

[Problem that this idea attempts to solve]

The relationship between the voltage that drives the DC motor 5 and the deviation is a linear relationship as shown in FIG. 4.
For this reason, there is a lack of torque near the equilibrium point, so
There was a problem in that the system did not restart easily, resulting in a wide dead zone and poor indication accuracy. In addition, when the gain was increased to improve this problem, a hunting phenomenon occurred, resulting in instability.

The purpose of this invention is to provide a self-balancing instrument that eliminates the lack of torque when starting a DC motor.

[Means for solving problems]

This invention includes a hysteresis circuit that generates a hysteresis output based on the deviation output of a deviation amplifier, a circuit that drives a DC motor in forward or reverse rotation according to the positive and negative forces of this hysteresis circuit, and a circuit that detects the zero output of the hysteresis circuit. This automatic balancing instrument is equipped with a zero detection circuit that locks the DC motor.

〔Example〕

FIG. 1 is an explanatory diagram showing an embodiment of the invention, and the same reference numerals as in FIG. 3 indicate the same components. In the figure, the deviation between the input signal of the input terminal 1 and the feedback signal of the sliding resistor 2 is compared by the deviation amplifier 3, and the deviation power is transmitted to the feedback circuit through the input resistor R3 through the diodes D1, D2, D3, D4. Hysteresis (comparison) consisting of an operational amplifier OP, etc., to which voltages +V and -V are supplied via resistors R4 and R5.
The voltage is supplied to the circuit 7, and a hysteresis output is obtained, which is zero when the deviation is near zero, as shown in FIG. 2, and is a sufficiently high driving voltage at other times. The drive circuit 4 corresponds to the high positive and negative drive voltages of the hysteresis circuit 7.
Either transistor Tr1 or Tr2 is turned on to drive the DC motor 5 in forward or reverse rotation, and the brush of the sliding resistor 2 interlocked with the DC motor 5 is moved to perform an automatic balancing operation. Further, the zero output of the hysteresis circuit 7 is detected by the zero detection circuit 8, and the outputs of the transistors Tr1 and Tr2 are grounded by the switch S, thereby locking the DC motor 5. The hysteresis circuit 7, also called a dead zone comparator, is
See Publication No. 36911, etc.

In other words, as shown in FIG. 2, the drive voltage of the DC motor 5 is completely zero when the deviation is around zero, and the operation is completely stopped by the zero detection circuit 8, and when the deviation is out of the zero range. Since the drive voltage is large, positive or negative, the DC motor 5
starts rotating.

In this way, a complete stop at the equilibrium point and a rapid start-up are possible.

[Effect of idea]

As mentioned above, in this invention, the DC motor is driven by the output of the hysteresis circuit for deviations, making it easy to start the motor, and the motor is completely locked near the equilibrium point, reducing the dead zone. , resulting in extremely high performance. It is particularly suitable for application to an automatic balancing recorder driven by a DC power source.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing one embodiment of this invention, and FIGS. 3 and 4 are explanatory diagrams showing a conventional example. 1... Input terminal, 2... Sliding resistance, 3... Deviation amplifier, 4... Drive circuit, 5... DC motor, 6
...Recording device, 7...Hysteresis circuit, 8...
Zero detection circuit.

Claims (1)

[Scope of utility model registration request] An automatic balancing instrument that compares an input signal and a feedback signal using a deviation amplifier and drives a DC motor according to the deviation to automatically balance the device, includes a hysteresis circuit that generates a hysteresis output based on the deviation output of the deviation amplifier; The present invention includes a drive circuit that drives the DC motor in forward or reverse rotation according to the positive and negative outputs of the circuit, and a zero detection circuit that detects the zero output of the hysteresis circuit and grounds the output to lock the DC motor. Features an automatic balancing instrument.