JP3701899B2 - Starter and method for reducing peak current - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a starting device and method for reducing peak current, and more particularly to a starting device and method applied to an induction circuit such as a DC motor.
[0002]
[Prior art]
In general, the structure of a motor is provided with mechanical contacts of brushes and commutators, and whenever the motor starts, a peak current is generated in the motor. This phenomenon is caused by improper wiring of the electric wires and performance defects of the power supply itself. In known designs, there is no buffer circuit to prevent peak current generation, and the motor suddenly starts up from rest, causing excessive mechanical shock in the motor and damaging the motor.
[0003]
Several methods have been proposed to prevent this phenomenon, one of which uses a protection circuit such as a capacitor or resistor, which is placed close to the motor power supply after the peak current has occurred. And protect the motor. However, this protection circuit is also not suitable for long-term use. Another method is to start the motor step by step with a complex and expensive circuit, for example by using a circuit with multiple filters to form a pulse width modulated (PWM) signal. And output to the transistor. The switching interval of the transistor changes according to the change of the PWM duty cycle. Thereby, the average current flowing through the motor is changed to further control the rotation speed of the motor. However, such a method of starting the motor in stages requires a complicated and expensive circuit. In addition, this PWM circuit produces electroacoustic sound during motor start-up, and the reliability of internal electronic parts is also affected under numerous impacts.
[0004]
Thus, there is a need to provide a simplified and economical start-up device and a method that remedies the disadvantages of the above-mentioned known techniques.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a starting device and to reduce a peak circuit generated when an induction circuit such as a motor or a DC motor is operated.
[0006]
Another object of the present invention is to provide a simple and inexpensive starting device, and to reduce the peak current generated when the conductive circuit starts up without affecting the reliability of the internal electronic parts.
[0007]
[Means for Solving the Problems]
According to the present invention, the activation device is electrically connected to the induction circuit, generates a first signal corresponding to the signal output by the induction circuit, and is electrically connected to the signal generator, A signal is converted into a second signal, compared with a reference signal, and electrically connected to a comparison circuit that generates a control signal, an induction circuit, and a comparison circuit, receives the control signal, and corresponds to the control signal It comprises a control device that increases the current input to the induction circuit, thereby reducing the peak current that occurs when the induction circuit is activated.
[0008]
Preferably, the signal generator is a frequency generator and the first signal is a periodic square wave signal with a frequency proportional to the rotational speed of the motor.
[0009]
According to the present invention, the comparison circuit is electrically connected to the signal generator, the signal converter for converting the first signal into the second signal, the signal converter, and the second signal and the reference signal. And a comparator that outputs a control signal or a PWM signal.
[0010]
The signal converter can be a triangular wave generation circuit, which converts a square wave signal into a triangular wave signal or a sawtooth signal and compares it with a reference signal.
[0011]
In addition, the activation device further comprises a charging circuit or a resistive capacitor circuit electrically connected between the comparator and a voltage source that supplies the required voltage to the induction circuit and provides a reference signal.
[0012]
In another embodiment of the present invention, the activation device further includes a drive circuit electrically connected between the induction circuit and the signal generator to drive the induction circuit.
[0013]
The control device can be an electronic switch or transistor, gradually increasing the current through the induction circuit corresponding to the control signal.
[0014]
It is another object of the present invention to provide a starter and to reduce the peak current that occurs when the induction circuit is activated.
[0015]
This startup method is
(A) providing a first signal corresponding to the signal output by the induction circuit;
(B) converting the first signal into a second signal and comparing it with a reference signal to generate a control signal;
(C) A step of gradually increasing the current flowing through the induction circuit corresponding to the control signal, and reducing the peak current generated when the induction circuit operates.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In order to further clarify the above-described objects, features, and advantages of the present invention, preferred embodiments of the present invention will be given below and described in more detail with reference to the drawings.
[0017]
The present invention provides an activation device that reduces the peak current that occurs when an induction circuit such as a motor or DC motor is activated. The induction circuit is exemplified by a DC motor. FIG. 1 is a view showing a preferred specific example of the activation device of the present invention. The starting device is
A signal generator 12 electrically connected to the motor 11 for generating a first signal corresponding to the signal output by the motor 11;
A comparison circuit that is electrically connected to the signal generator 12, converts the first signal into a second signal, compares it to a reference signal, and generates a control signal;
A controller 16 that is electrically connected to the motor 11 and the comparison circuit, receives a control signal, and gradually increases a current flowing through the motor corresponding to the control signal;
It reduces the peak current that occurs when the motor is running.
[0018]
The signal generator 12 is preferably a frequency generator and generates a periodic square wave signal (ie, a first signal) according to the rotational speed of the motor. The frequency of this periodic square wave signal is proportional to the rotational speed of the motor.
[0019]
The comparison circuit includes a signal converter 13 and a comparator 14. The signal converter 13 is electrically connected to the signal generator 12 to convert the square wave signal into a triangular wave signal or a sawtooth signal, and to be a triangular wave generating circuit that compares it with a reference signal Verf (or called a target voltage). I can do it. The comparator 14 is electrically connected to the signal converter 13, compares the triangular wave signal or sawtooth signal with the reference signal, and outputs a PWM signal (control signal). The reference signal is provided by a charging circuit or resistor capacitor 15 that is electrically connected between the comparator 14 and the voltage source Vcc and provides the voltage required by the motor.
[0020]
The controller can be an electronic switch, preferably a transistor 16 and gradually increase the current through the motor 11 after receiving the PWM signal. Thereby, the peak current generated when the motor 11 operates can be reduced, and the rotational speed of the motor can be controlled.
[0021]
In FIG. 2, the relationship between the signal conversion, the formed signal change and the rotation speed of the motor in the starter of the present invention will be described in detail. The FG signal generated by the frequency generator 12 is a square wave signal that is proportional to the rotational speed of the motor, as shown in FIG. After the periodic square wave signal is converted into the triangular wave signal or sawtooth signal shown in (b) by the triangular wave generation circuit 13, the triangular wave signal is input to the comparator 14 and provided by the resistance capacitor circuit 15. Is compared with the reference signal Vref.
[0022]
As a result of the comparison, the comparator 14 outputs a PWM signal (indicated by (c)) to the transistor 16. When the PWM signal is received by the transistor 16, the motor 11 starts to rotate. While the input PWM signal disappears (that is, the state of the PWM signal changes from a high potential to a low potential), the transistor switches to a closed state, but due to inertia, the motor continuously rotates for a certain time. Transistor switching can be used to control the current provided to the motor, and the rotational speed of the motor increases (shown in FIG. 2 (d)) until the motor rotates at full speed. Such a simple circuit design can effectively reduce the peak current generated when the motor operates.
[0023]
FIG. 3 shows another preferred embodiment of the starting device according to the present invention. The starting device further comprises a drive circuit 17 electrically connected between the motor 11 and the signal generator 12, and the motor 11 is driven.
[0024]
The structure of the activation device is the same as that of FIG. 1 except that the activation device includes a drive circuit electrically connected between the motor 11 and the signal generator 12.
[0025]
In summary, the present invention provides a simple and inexpensive circuit design for the starter, reduces the peak current that occurs when the motor is operating, controls the current provided to the motor, and the rotational speed of the motor at start-up is It gradually increases, thereby reducing the occurrence of peak current and protecting the motor's internal devices or devices connected to the motor from damage.
[0026]
In the present invention, preferred embodiments have been disclosed as described above. However, the present invention is not limited to the present invention, and any person who is familiar with the technology can use various methods within the spirit and scope of the present invention. You can add variation and hydration.
[0027]
【The invention's effect】
Providing start-up devices, reducing peak circuits that occur when induction circuits such as motors and DC motors operate, and reducing peak currents that occur when conducting circuits start without affecting the reliability of internal electronic parts To do.
[Brief description of the drawings]
FIG. 1 shows a preferred embodiment of an activation device according to the present invention.
FIG. 2 is a diagram showing a relationship between a variation of a signal formed with a converter and a rotation speed of a motor in the starting device of the present invention.
FIG. 3 shows another preferred embodiment of an activation device according to the present invention.
[Explanation of symbols]
11 Motor 12 Signal Generator 13 Signal Converter 14 Comparator 15 Resistor Capacitor 16 Control Device Vcc Voltage Source Vref Reference Signal 17 Drive Device

Claims (14)

A starter that reduces the peak current generated when the motor starts,
A signal generator electrically connected to the motor and generating a first signal in accordance with a rotational speed of the motor;
A comparator circuit electrically connected to the signal generator and generating a control signal based on the first signal and a reference signal;
Reduces the peak current generated when starting the motor by electrically connecting to the comparison circuit and the motor, receiving the control signal, and gradually increasing the current input to the motor according to the control signal and a control device for,
The activation device according to claim 1, wherein the reference signal is provided by a charging circuit electrically connected between the comparator and a voltage source for supplying a necessary voltage to the motor .   The starter according to claim 1, wherein the signal generator is a frequency generator.   The starter according to claim 1, wherein the first signal is a periodic square wave signal and has a frequency proportional to a rotation speed of the motor. The comparison circuit is
A signal converter for converting the first signal into the second signal;
4. The activation device according to claim 3, wherein the activation device is electrically connected to the signal converter and the control device, compares the second signal with the reference signal, and outputs the control signal.   5. The starter according to claim 4, wherein the signal converter is a triangular wave generating circuit that converts the square wave signal into one of a triangular wave signal and a sawtooth signal.   The starter according to claim 1, wherein the control signal is a pulse width modulation (PWM) signal for controlling a rotation speed of the motor.   The starter according to claim 6, wherein the control device is an electronic switch that gradually increases the current input to the motor corresponding to the PWM signal.   The starter according to claim 1, further comprising a drive circuit electrically connected between the motor and the signal generator to drive the motor. A method for reducing the peak current that occurs when an induction circuit is activated,
Providing a first signal corresponding to the signal output by the induction circuit;
Converting the first signal into a second signal and comparing with a reference signal to form a control signal;
(C) increasing the current flowing through the induction circuit corresponding to the control signal,
The reference signal is provided by a charging circuit electrically connected between the comparator and a voltage source that supplies the required voltage to the motor, and reduces the peak current that occurs when the induction circuit is activated. A start method characterized by the above.   10. The starting method according to claim 9, wherein the induction circuit is either a motor or a DC motor.   The startup method according to claim 9, wherein the first signal is a periodic square wave signal and has a frequency proportional to a rotation speed of the motor.   12. The starting method according to claim 11, wherein in the step (b), the square wave signal is converted into one of a triangular wave signal and a sawtooth signal by a triangular wave generation circuit.   The start-up method according to claim 10, wherein the control signal is a pulse width modulation signal for controlling a rotation speed of the motor.   14. The starting method according to claim 13, further comprising the step of repeating step (a) and step (c), and increasing the rotational speed of the motor until the motor rotates at full speed.

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