JPS6032588A - Electronic motor device - Google Patents

Abstract

PURPOSE:To prevent an overcurrent from flowing to an electronic part even when a rotational shaft is locked by applying an automatic gain regulator for controlling a servo command value. CONSTITUTION:The rotating speed obtained by the rotation of an electronic motor is converted by a frequency generator 3 into frequency, and the difference between the frequency FG and a set frequency FS is inputted to a servo circuit 1 for outputting a control signal to a drive circuit 2. An automatic gain regulator 4 outputs a servo command P when the value of a power source voltage Vee rises higher than a reference voltage Vref. Since the gain of the circuit 1 is dropped by the command P, the output of the circuit 1 is eventually controlled to the same amplitude as that when the power source voltage Vee is rated value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic motor device that prevents overcurrent from flowing through an electronic circuit when a rotating shaft such as a spindle motor for a floppy disk is locked.

FIG. 1 is a block diagram showing an example of conventional electronic motor rotation speed control, in which there is a servo circuit 1 and a drive circuit 2 on the main side, and a frequency generator 3 on the feedback side. Note that the p-tor, stator, etc. that make up the electronic motor are omitted.
The frequency detection part is represented as a frequency generator 3.

The rotation speed control section of a conventional electronic motor is configured as shown in Figure 1, and a set frequency FB is set in advance.
The rotational speed obtained by the rotation of the electronic motor is converted into a frequency by the frequency generator 3, and this frequency F. and set frequency F
8 and inputs the difference output to the servo circuit IK which outputs a control signal to the drive circuit 2.

Then, the drive circuit 2 operates according to the control signal outputted by the servo circuit 1, and the electronic motor is rotated at a predetermined number of rotations according to the rotation command S. Therefore, the electronic motor rotates while maintaining a predetermined rotational speed due to this closed loop circuit.

As described above, when the electronic morph rotates while maintaining a predetermined rotation speed, even if the power supply voltage vce increases by about 105 points above the rated voltage, there is no effect on the current flowing through the electronic components. However, if a load is applied to the rotating shaft of the electronic motor and the rotating shaft locks, if the power supply voltage V□ is about 10% higher than the rated voltage, an overcurrent will flow to the electronic components and cause an adverse effect. there were.

This invention was made in view of the above points, and is an electronic morph that prevents overcurrent from flowing to electronic components even when the rotating shaft is locked by adding an automatic gain adjustment circuit that controls the servo command value. It provides equipment. The present invention will be explained below with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the present invention, in which the same reference numerals as in FIG. 1 indicate the same parts, and 4 is an automatic gain adjustment circuit for controlling the servo command value inputted to the servo circuit IK.

FIG. 3 is a circuit diagram showing an example of the automatic gain adjustment circuit 4.
R, -R, are resistors, VR, , VR, are variable resistors,
zD is a Zener diode, A is a seven-channel transistor, Tr is a transistor, and Vee is a power supply voltage.

Next, the operation will be explained. Even if the power supply voltage vte fluctuates, because of the Zener diode zO, the non-inverting terminal of amplifier A always has a constant reference voltage vr, f, and the paper inverting terminal has
Power supply voltage vee is divided by resistors R, , R3 to obtain input voltage V1. is applied through resistor R3. therefore,
Power supply voltage V. The input voltage V1. fluctuates;
When the value rises above the reference voltage Vr@f (this is when the power supply voltage vce rises by 10% from the rated value), an output is output from the amplifier 8, the transistor Tr becomes conductive, and the servo command P is sent from the emitter. Get out. This servo command P
Since the gain of servo circuit 1 in FIG. 2 is reduced by , the output of servo circuit 1 becomes #! The 5-station power source pressure vce should be controlled to the same level as when it is at the rated value.

This invention adds an automatic gain adjustment circuit 4 using non-inverting amplification to the amplifier shown in FIG. 3 to the circuit 5 shown in FIG. 2 to control the servo circuit 1.
Automatic gain v4 even if l rises by about lO% from the rated voltage
Adjustment circuit 4 automatically adjusts the gain, 4! Then, the servo command value is input to the servo circuit IK so that it becomes the same as the control signal when the power supply voltage (2) is the rated voltage. Therefore, even if the rotation axis of the electronic morph locks due to a load, etc., there will be no overload on the electronic components.
VL can be prevented and other circuits will not be adversely affected.

As explained above, the electronic motor device of 5VC1 of this invention is
By adding a gain adjustment circuit, the control signal output by the servo circuit is automatically adjusted to the same level as the rated voltage, so even if the rotating shaft is locked due to a load, overcurrent to electronic components can be prevented, and There are five advantages in that it does not adversely affect other circuits.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of conventional electronic motor rotation speed control, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a block diagram showing an example of the automatic gain adjustment circuit in Fig. 2. FIG. 2 is a circuit diagram showing an example. In the figure, 1 is a servo circuit, 2 is a drive circuit, 3 is a frequency generator, 4 is an automatic gain adjustment circuit, R1-R7 are resistors, and V
R,,VR,, are variable resistors, ZD is a Zener diode, A is an amplifier, Tr is a transistor, and vec is an i source voltage. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In an electronic motor device R that has a closed loop consisting of a servo circuit, a drive circuit controlled by the servo circuit, and a frequency generator, and drives an electronic motor at a set frequency, the output value of the servo circuit is caused by fluctuations in the power supply voltage. An electronic motor device characterized by being equipped with an automatic gain adjustment circuit: JF4, which automatically adjusts the gain to a constant value regardless of the situation.