JPS6330239Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a control circuit for driving and controlling an electric motor.

Generally, this type of device is provided with a load ammeter inside or outside the control device in order to confirm or constantly monitor the load current of the motor. Furthermore, a function is usually added to display the location of the abnormality in the control device.

In such a control device, during normal use, the load current of the motor can be ascertained by the load ammeter and it can be confirmed that the motor is in a normal operating state. For example, if the electric motor becomes overloaded, the control device detects this overloaded state,
The operation of the electric motor is stopped and the fact that the electric motor is overloaded is indicated by an indicator lamp or the like.

Conventional electric motor control devices configured in this manner are provided with a load ammeter that operates during normal operation and a display device that operates when an abnormality occurs, making the device more complex and large. There were flaws.

This invention was developed in view of the drawbacks of the conventional control device, in which when the motor is overloaded and the operation is stopped, the load current of the motor naturally becomes zero, and at this time the load ammeter does not operate. Not yet. Furthermore, when the electric motor is operating normally, the display device that displays abnormal conditions is not operating.
Therefore, the above-mentioned load ammeter and display device were designed with the focus on the fact that when one of them is operating, the other is not, and displays the load current when the motor is operating normally. It is an object of the present invention to provide a control device that is inexpensive and compact by providing a display device that has a function of displaying an abnormal location when an abnormality occurs.

An embodiment of this invention will be described below with reference to the drawings. In the figure, 1 is a control circuit, and 2 is a power amplification circuit, which receives commands from the control circuit 1 and amplifies power so that the electric motor 4 serving as a load can rotate. 3
5 is a load current detection circuit that detects the load current; 5 is a display switching circuit that switches between displaying the load current and the contents of the abnormal condition; and 6 is a display device that displays the magnitude of the load current or the abnormal location at the time of an abnormality. Display using light emitting diodes.

Next, the operation of this device will be explained.

Under normal operating conditions, the display device 6 is
The number of light emitting diodes proportional to the magnitude of the load current flowing through the motor 4 lights up, and functions as a level meter.

In addition, when an abnormality occurs, the load current to the motor 4 is cut off, and the display switching circuit 5 switches the control circuit 1
By switching to display the abnormality contents as appropriate, the light emitting diode corresponding to the abnormality contents lights up, thereby displaying the abnormality contents. At this time, since no load current is flowing through the motor 4, there is no need for a load current display function, and the above operation is possible.

As described above, according to this invention, there is a control circuit that controls the operation of the electric motor, a detection circuit that detects the load current flowing through the electric motor, and a detection circuit that detects whether the electric motor and the control circuit are normal or abnormal, and according to the detected contents. a display switching circuit for switching the display, and a plurality of light emitting diodes, receiving a signal from the display switching circuit,
During normal operation, the number of the light emitting diodes lit up corresponds to the magnitude of the load current flowing through the motor, and among the light emitting diodes that light up according to the magnitude of the load current during abnormality, only the light emitting diode corresponding to the content of the abnormality lights up. Since the structure is equipped with a display device that lights up, the multiple light emitting diodes used as level meters for the load current can also be used as light emitting diodes to display the abnormal location in the event of an abnormality. In a control device for an electric motor, the device can be made inexpensive, and the circuit space of the printed circuit board can be reduced, so that the device can be miniaturized.

[Brief explanation of drawings]

The figure is a block diagram showing an embodiment of this invention, in which 1 is a control circuit, 2 is a power amplifier circuit, 3 is a load current detection circuit, 4 is an electric motor, 5 is a display switching circuit,
6 is a display device.

Claims (1)

[Scope of utility model registration request] a control circuit that controls the operation of the electric motor; a detection circuit that detects a load current flowing through the electric motor; and a display switching circuit that detects whether the electric motor and the control circuit are normal or abnormal and switches a display depending on the detected content;
It has a plurality of light emitting diodes, receives a signal from the display switching circuit, and when normal, the number of light emitting diodes lights up according to the magnitude of the load current flowing to the motor, and when abnormal, the number of light emitting diodes lights up according to the magnitude of the load current. A control device for an electric motor, comprising a display device that lights up only the light emitting diodes corresponding to the abnormality among the light emitting diodes that light up.