KR101688274B1 - Energy Saving and Voltage Sag Compensating Magnetic Contactor - Google Patents

Abstract

The present invention relates to a power saving and voltage sag compensating electromagnetic contactor, comprising: a power input unit for supplying an alternating current; A first capacitor for controlling an alternating current supplied through the power input unit; A first switch connected to the first capacitor in parallel; A rectifier circuit unit for converting an AC current transmitted through the first capacitor or the first switch unit into a DC current and outputting the DC current; And a drive coil for magnetizing the fixed iron core by the direct current, wherein the first switch unit is turned on at the time of initial startup of the apparatus and transmits an alternating current supplied through the power input unit to the drive coil, Is brought into an off state when it is attached to the fixed core.

Description

[0001] The present invention relates to a power saving and voltage sag compensating magnetic contactor,

The present invention relates to an electromagnetic contactor that compensates for power saving and voltage sags.

The electromagnetic switch is a device for opening or opening the flow of electricity by using an electromagnet, and is an electronic contactor widely used in various industries. The conventional electromagnetic contactor controls the flow of electricity using an electromagnet. In the off state, the standby power is not consumed. However, in the on state, the standby power consumption for maintaining the electromagnet continuously is wasted .

Fig. 1 shows a circuit diagram of a conventional power saving electromagnetic contactor, Fig. 2 is a cross-sectional view in a switched-on state (a) shows operation of a first plunger and a valve, FIG.

1 and 2, power is supplied to the first solenoid 100 as soon as power is input to the power input unit 102, and an induced magnetic field is generated. By the induction magnetic field of the first solenoid 100, The first plunger 110 is pulled by the first solenoid 100. As the first plunger 110 moves, the movable contact and the fixed contact of the opening and closing switch 120 are turned on.

The first protrusion 114 of the first plunger 110 passes through the valve 150 to fix the latching jaw of the first protrusion 114 to the valve 150 so that the valve 150 is turned off Lt; / RTI >

At this time, the rectifying circuit portion 162 of the blocking circuit portion 160 converts the AC power input to the power input portion 102 into DC power and charges the charging portion 164, and when the power input is detected, The switch 166 connected to the second solenoid 130 is turned off and the second solenoid 130 is not powered.

Since the power is not applied to the second solenoid 130, the V-shaped second projection 144 of the second plunger 140 is kept in the initial state in which the upper surface of the valve 150 is completely exposed.

As described above, in the conventional power saving type electromagnetic contactor, when the power source is applied to the power input part 102 in the switch-on state, the open / close switch 120 maintains the turn-on state continuously, but the first solenoid 100 and the second solenoid 100 No power is supplied to the first solenoid 100, so that power consumption by the first solenoid 100 does not occur even in the switch-on state. Therefore, the power saving type electromagnetic contactor of the related art has almost no standby power consumption even in the switch-on state, so that power saving is possible.

However, the conventional power saving electromagnetic contactor has a locking structure in which the engagement protrusion of the first protrusion 114 is fixed to the valve 150 in order to continuously maintain the turn-on state of the open / close switch 120, And the first protrusion 114 is broken or worn, it is difficult to operate normally.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power saving and voltage sag compensating electromagnetic contactor which does not require a locking structure and has a simple structure.

Another object of the present invention is to provide a power saving and voltage sag compensating electromagnetic contactor that is not open to voltage sags as much as 40% of the rated voltage.

According to a first embodiment of the present invention, a power saving and voltage sag compensating electromagnetic contactor according to the present invention includes: a power input unit for supplying an alternating current; A first capacitor for controlling an alternating current supplied through the power input unit; A first switch connected to the first capacitor in parallel; A rectifier circuit unit for converting an AC current transmitted through the first capacitor or the first switch unit into a DC current and outputting the DC current; And a drive coil for magnetizing the fixed iron core by the direct current, wherein the first switch unit is turned on at the time of initial startup of the apparatus and transmits an alternating current supplied through the power input unit to the drive coil, Is brought into an off state when it is attached to the fixed core.

A second switch part connected in parallel to the first switch part and transmitting an alternating current supplied through the power input part by an on-off operation; A second capacitor connected to a rear end of the second switch unit and controlling an AC current transmitted through the second switch unit; A DC power generator for generating a DC power using the DC current; And a control unit which detects a current flowing in the drive coil and turns on the second switch unit when the detected current is equal to or less than a predetermined first current and turns off the second switch unit when the detected current is equal to or greater than a predetermined second current And a sag control circuit.

Preferably, the sag control circuit includes: a voltage supplier for supplying DC power generated by the DC power generator to the sag control circuit; A current detector for detecting a current flowing through the drive coil; And a coil drive current comparator for comparing the current detected by the current detector with a predetermined first current and a second current.

Preferably, the first switch unit is a B contact switch which is closed before being operated and opened when operated.

Further, according to the second embodiment of the present invention, the power saving and voltage sag compensating electromagnetic contactor according to the present invention includes: a power input unit for supplying an alternating current; A first capacitor for controlling an alternating current supplied through the power input unit; A first switch connected to the first capacitor in parallel; A rectifier circuit unit for converting an AC current transmitted through the first capacitor or the first switch unit into a DC current and outputting the DC current; A DC power generator for generating a DC power using the DC current; A driving coil for magnetizing the fixed core by the DC current; And a contactor start control circuit which is driven by the DC power supply and turns on the first switch unit when the DC power supply is higher than a predetermined voltage and turns off the first switch unit when the movable iron core is stuck to the fixed iron core .

Preferably, the contactor starting control circuit includes: a voltage supplier for supplying the direct current power generated by the direct current power generator to the contactor starting control circuit; And a contactor DC power supply comparator for comparing the voltage supplied by the voltage supply with a predetermined voltage.

Preferably, the first switch unit is a photo triac.

As described above, according to the present invention, it is possible to provide a power saving and voltage sag compensating electromagnetic contactor which does not require a locking structure and has a simple structure and can prevent a breakdown due to breakage or wear of the first protrusion can do.

Further, according to the present specification, it is possible to provide a power saving and voltage sag compensating electromagnetic contactor that is not opened to a voltage of about 40% of the rated voltage.

1 is a circuit diagram of a conventional power saving electromagnetic contactor,
2 is a sectional view of a conventional power saving electromagnetic contactor in a switched-on state,
3 is a circuit diagram of a power saving and voltage sag compensating electromagnetic contactor according to a first embodiment of the present invention,
FIG. 4 is a flowchart illustrating a voltage sag compensation method for a power saving and voltage sag compensating electromagnetic contactor according to a first embodiment of the present invention. FIG.
5 is an AC input terminal connection diagram of the power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention,
6 is a partial cut-away view of a power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention,
FIG. 7 is a diagram showing an on-off state of a power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention;
8 is a circuit diagram of a power saving and voltage sag compensating electromagnetic contactor according to a second embodiment of the present invention,
9 is a graph comparing the current waveforms of the drive coils of the conventional electromagnetic contactor with the current waveforms of the drive coils of the power saving and voltage sag compensating electromagnetic contactors according to the present invention,
10 is a diagram for comparing power consumption of a conventional electromagnetic contactor and a power saving and voltage sag compensating electromagnetic contactor according to the present invention.

It is noted that the technical terms used herein are used only to describe specific embodiments and are not intended to limit the invention. It is also to be understood that the technical terms used herein are to be interpreted in a sense generally understood by a person skilled in the art to which the present invention belongs, Should not be construed to mean, or be interpreted in an excessively reduced sense. Further, when a technical term used herein is an erroneous technical term that does not accurately express the spirit of the present invention, it should be understood that technical terms that can be understood by a person skilled in the art are replaced. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Also, the singular forms "as used herein include plural referents unless the context clearly dictates otherwise. In the present application, the term "comprising" or "comprising" or the like should not be construed as necessarily including the various elements or steps described in the specification, Or may be further comprised of additional components or steps.

Further, the suffix "module" and "part" for components used in the present specification are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

Furthermore, terms including ordinals such as first, second, etc. used in this specification can be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

3 shows a circuit diagram of a power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention.

Referring to FIG. 3, the power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention includes a contactor-driven power saving circuit 310.

The contactor-driven power-saving circuit 310 may include a power input unit 312, a first capacitor C1, a first switch unit MS, a rectifier circuit unit D, a drive coil L, and the like.

The power input unit 312 supplies an alternating current according to an applied AC voltage. Here, the surge arrester T for protecting the circuit in the electromagnetic contactor from surge, spark, noise, and the like may be connected in parallel to the power input unit 312. The surge observer (T) may include TNR and SNR.

The first capacitor C1 controls the alternating current supplied through the power input unit 312. [

The first switch unit MS is a B contact switch that is opened when the switch MS is operated before being operated and is connected to the first capacitor C1 in parallel. And when the movable iron core, which will be described later, is magnetized and moves in the direction of the fixed iron core to be attached to the fixed iron core, it is turned off. A first resistor R1 may be connected to a rear end of the first switch unit MS to limit a current of an alternating current transmitted through the first switch unit MS.

The rectifying circuit part D converts the AC current transmitted through the first capacitor C1 or the first switch part MS into a DC current and outputs the DC current. To this end, the rectifying circuit portion D may be a bridge diode.

The driving coil L surrounds the fixed iron core and magnetizes the fixed iron core by the direct current outputted from the rectifier circuit portion D.

Meanwhile, the power saving and voltage sag compensating electromagnetic contactor according to the present invention may further include a sag detection and driving circuit 320 and a sag control circuit 330 to ensure stable operation from a voltage new.

The sag detecting and driving circuit 320 includes a second switch unit Q, a second capacitor C2, and a DC power generating unit 322. [

The second switch unit Q is connected in parallel to the first capacitor C1 in the same manner as the first switch unit MS and transmits the alternating current supplied through the power input unit 312 by the on-off operation. Here, the second switch unit Q may include a phototriac.

The second capacitor C2 is connected to the rear end of the second switch unit Q and controls the alternating current transmitted through the second switch unit Q. [

The DC power generation unit 322 generates a DC power using the DC current outputted from the rectifying circuit unit D. That is, the DC power generator 322 generates a stable DC power source, for example, a DC power source capable of operating the sag control circuit 330 using the DC current output from the rectifier circuit part D, for example, 5V. To this end, the DC power generator 322 includes a second resistor R2, a first Zener diode Z1, a third capacitor C3, a third resistor R3, and a second Zener diode Z2 . The second resistor (R2) limits the voltage value of the DC voltage output from the rectifying circuit portion (D). The first Zener diode Z1 generates the first voltage using the DC voltage transmitted through the second resistor R2. The third capacitor C3 controls the first voltage generated by the first Zener diode Z1. The third resistor R3 limits the voltage value of the first voltage controlled by the third capacitor C3. The second Zener diode Z2 generates the second voltage as a stable DC voltage using the first voltage transmitted through the third resistor R3.

The sag control circuit 330 detects the current flowing through the drive coil L and turns on the second switch unit Q when the detected current is equal to or less than a predetermined first current (for example, 19 mA) When the voltage of the coil L reaches about 100% of the rated voltage and the detected current is equal to or greater than a predetermined second current (for example, 34 mA), the second switch unit Q is turned off. The sag control circuit 330 includes a voltage supplier 332 for supplying the DC power generated by the DC power generator 322 to the sag control circuit 330, And a coil drive current comparator 336 for comparing the current detected by the current detector 334 and the current detector 334 with a predetermined first current and a second current. In this regard, the power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention includes a fourth resistor R4 (R4) connected in parallel to the rear end of the drive coil L for detecting a current flowing in the drive coil L, And a third zener diode Z3. The current detector 334 may also be replaced by a voltage detector to detect the voltage through the voltage detector and to use the detected voltage to calculate the current.

Hereinafter, the startup and continuous operation of the power saving and voltage sag compensating electromagnetic contactor and the voltage sag compensating operation according to the first embodiment of the present invention will be described.

Starting and continuous operation

The first switch unit MS is turned on at the time of initial startup of the power saving and voltage sag compensating magnetic contactor (MC) according to the present invention. Accordingly, a current of about 400 mA flows to the drive coil L, so that the attracting force of the MC increases and the movable core of the electromagnet moves in the direction of the fixed core. That is, the MC is in the closed state.

When the first switch part MS is turned off, the current I flows through the first capacitor C1 to the drive coil L. [ At this time, since the movable iron core of the electromagnet is attached to the fixed iron core, the inductance of the driving coil L increases, and a DC current having a small ripple flows through the driving coil L. The magnitude of the DC current is about 25 mA when the AC voltage is 100% of the rated voltage. Since the movable iron core and the fixed iron core of the electromagnet are attached, the MC is in a continuous operation state by securing a sufficient attraction force.

Voltage sag compensation

When a voltage leaks to the AC voltage, the voltage of the drive coil L decreases and the current flowing in the drive coil L decreases.

When the AC voltage is lowered to about 70% of the rated voltage by the occurrence of a voltage drop in the AC voltage, the current flowing through the drive coil L also decreases. When the current flowing through the drive coil L reaches 19 mA, The output of the comparator 336 becomes high level to turn on the second switch unit Q and the current flows to the drive coil L through the second capacitor C2. Therefore, the current of the drive coil L rises to about 30 mA and the electromagnet is in a stable state.

When the voltage of the drive coil L reaches about 100% of the rated voltage and the current of the drive coil L increases to 34 mA due to the disappearance of the AC voltage, the coil drive current comparator 336 The output becomes low level (Low Level) and the second switch unit Q is turned off. Therefore, the current of the drive coil L becomes about 25 mA, and the electromagnet becomes a normal state.

4 is a flowchart illustrating a voltage sag compensation method of a power saving and voltage sag compensating electromagnetic contactor according to a first embodiment of the present invention.

Referring to FIG. 4, the sag control circuit 330 measures a current (hereinafter referred to as a 'driving current') flowing through the driving coil L (S410).

Subsequently, the sag control circuit 330 sets the counter value M to a predetermined reference value Mm (for example, 2500) because the drive current I is not measured from the beginning in driving the electromagnetic contactor, (S420). Here, the sag control circuit 330 continuously accumulates the counter value M when the counter value M is equal to or less than the predetermined reference value Mm (S422).

When the counter value M exceeds the preset reference value Mm, the sag control circuit 330 judges whether or not the drive current I is lower than a predetermined first current Id (for example, 19 mA) (S430). When the drive current I is equal to or less than the predetermined first current Id, the second switch unit Q is turned on (S432).

When the drive current I exceeds the predetermined first current Id, the sag control circuit 330 determines whether the drive current I is equal to or greater than a predetermined second current Iu (for example, 34 mA) (S440). If the driving current I is equal to or greater than the preset second current Iu, the second switch unit Q is turned off (S442).

6 is a partial cut-away view of a power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention. FIG. 5 is a schematic view showing the connection of the AC input terminal of the power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention, .

The contactor-driven power-saving circuit 310 according to the present invention may be mounted on one substrate 500, as shown in FIG. 5, and the substrate 500 may be mounted on a first plunger And a lower structure 620 including a second plunger.

FIG. 7 is a view showing the on / off state of the power saving and voltage sag compensating electromagnetic contactor according to the first embodiment of the present invention. FIG. 7 (a) shows the off state of the power saving and voltage sag compensating electromagnetic contactors according to the first embodiment of the present invention, and Fig. 7 (b) shows the power saving and voltage sag compensating electromagnetic contactors according to the first embodiment of the present invention. Voltage sag compensation on-state of the electronic contactor.

7A, the movable contact 712 of the opening / closing switch 710 and the stationary contactor 714 are in a turned off state when the MC is initially started, and the first switch portion MS is in the OFF state It is in the ON state. Accordingly, AC voltage is applied through the power input unit 312 and current flows to the driving coil, so that the movable iron core 720 of the electromagnet moves in the direction of the fixed iron core 730, The first switch unit MS is turned off.

When the first switch unit MS is turned off, the current I flows through the first capacitor C1 to the drive coil L. At this time, since the movable iron core 720 of the electromagnet is attached to the fixed iron core 730, the inductance of the drive coil L increases and a direct current having a small ripple flows through the drive coil L. Since the movable iron core 720 of the electromagnet is in contact with the fixed iron core 730, the MC is kept in a continuous operation state by ensuring a sufficient attraction force, and the opening / closing switch 710 maintains the turn-on state.

8 shows a circuit diagram of a power saving and voltage sag compensating electromagnetic contactor according to a second embodiment of the present invention.

8, the power saving and voltage sag compensating electromagnetic contactor according to the second embodiment of the present invention includes a contactor driving power saving circuit 810, a sag (SAG) detection and driving circuit 820 and a sag control circuit 830. The sag control circuit 830 includes a sag control circuit 830,

However, the first switch unit P according to the second embodiment of the present invention is electronically controlled unlike the switch unit MS of FIG. That is, the first switch unit P may include a photo triac. To this end, the power saving and voltage sag compensating electromagnetic contactor according to the second embodiment of the present invention further includes a contactor start control circuit 840. [

The contactor start control circuit 840 is driven by the DC power generated by the DC power generation unit 822 and supplies the first switch unit P to the contactor start control circuit 840 when the DC power is higher than a predetermined voltage Turn on. Further, the contactor start control circuit 840 turns off the first switch portion P when the fixed iron core is magnetized to move the movable iron core in the fixed iron core direction.

The contactor start control circuit 840 includes a voltage supplier 842 for supplying the DC power generated by the DC power generator 822 to the sag control circuit 830 and the contactor start control circuit 840, And a contactor DC power source comparator 844 for comparing the voltage supplied from the contactor 842 with a predetermined voltage. Here, the voltage supplier 842 may be included in the sag control circuit 830 as in FIG. 3, or included in the contactor start control circuit 840 as described above.

Hereinafter, the startup and continuous operation of the power saving and voltage sag compensating electromagnetic contactor and the voltage sag compensating operation according to the second embodiment of the present invention will be described.

Starting and continuous operation

The current I flows to the drive coil L through the first condenser C1. At this time, since the impedance of the first capacitor C1 is large and a sufficient current can not flow in the driving coil L, the electromagnet of the power saving and voltage sag compensating electromagnetic contactor (MC ' And becomes an open state.

Thereafter, when the direct current power generated by the direct current power generator 822 by the pulsating voltage applied to the drive coil L increases from 0 to exceed 3.3V, the contactor direct current power comparator 840 of the contactor start control circuit 840 844 operate in a high level state.

Accordingly, the contactor start control circuit 840 turns on the first switch portion P, and a current of about 400 mA flows in the drive coil L, so that the attracting force of the MC increases so that the movable core of the electromagnet moves in the fixed core direction do. In the second embodiment of the present invention, the time for which the first switch unit P is turned on is 80 ms, and the movable iron core is attached to the fixed iron core during this period. That is, the MC is in the closed state.

When the first switch unit P is turned off, the current I flows through the first capacitor C1 to the drive coil L. At this time, since the movable iron core of the electromagnet is attached to the fixed iron core, the inductance of the driving coil L increases, and a DC current having a small ripple flows through the driving coil L. The magnitude of the DC current is about 25 mA when the AC voltage is 100% of the rated voltage. Since the movable iron core and the fixed iron core of the electromagnet are attached, the MC is in a continuous operation state by securing a sufficient attraction force.

Voltage sag compensation

When a voltage leaks to the AC voltage, the voltage of the drive coil L decreases and the current flowing in the drive coil L decreases.

When the AC voltage is lowered to about 70% of the rated voltage by the occurrence of a voltage drop in the AC voltage, the current flowing through the drive coil L also decreases. When the current flowing through the drive coil L reaches 19 mA, The output of the comparator 834 becomes high level to turn on the second switch unit Q and the current flows to the drive coil L through the second capacitor C2. Therefore, the current of the drive coil L rises to about 30 mA and the electromagnet is in a stable state.

When the voltage of the drive coil L reaches about 100% of the rated voltage and the current of the drive coil L increases to 34 mA due to the disappearance of the AC voltage, the coil drive current comparator 834 The output becomes low level (Low Level) and the second switch unit Q is turned off. Therefore, the current of the drive coil L becomes about 25 mA, and the electromagnet becomes a normal state.

9 is a graph comparing a current waveform of a drive coil of a conventional electromagnetic contactor with a current waveform of a drive coil of a power saving and voltage sag compensating electromagnetic contactor according to the present invention. 9A is a graph showing a current waveform of a drive coil of a conventional electromagnetic contactor, FIG. 9B is a graph showing a current waveform of a drive coil of a power saving and voltage sag compensating electromagnetic contactor according to the present invention Fig.

As shown in Fig. 9 (a), an alternating current flows in the drive coils of the conventional electromagnetic contactor. For example, an alternating current of about 33 to 40 mA flows through a 20A class electromagnetic contactor. Therefore, as shown in FIG. 10A, a conventional electromagnetic contactor generates a large loss in the short-circuit ring 1010, the iron cores 1020 and 1030, and the drive coil 1040, so that the power consumption is about 2 W .

9 (b), in the power saving and voltage sag compensating electromagnetic contactor according to the present invention, even if the first switch part MS, P is turned off, Since the current (I) flows, a DC current having a small ripple flows through the drive coil of the power saving and voltage sag compensating electromagnetic contactor. Therefore, in the electromagnetic contactor according to the present invention, as shown in FIG. 10B, a resistance loss occurs only in the drive coil 1040 '. For example, a DC current of about 25 mA flows to a 20A class contactor, resulting in about 0.3W of power consumption, which can reduce power consumption by about one-seventh compared to conventional contactors.

That is, the conventional electromagnetic contactor has a short-circuit ring 1010 in the fixed core and a resistance loss occurs, and an AC magnetic field passes through the iron cores 1020 and 1030, thereby generating iron loss. However, Since the contactor has no short-circuited ring and uses DC voltage, there is no loss due to short-circuit ring and iron core, and resistance loss occurs only in the drive coil. Accordingly, the power saving and voltage sag compensating electromagnetic contactor according to the present invention can reduce power consumption.

The embodiments disclosed herein have been described with reference to the accompanying drawings. Thus, the embodiments shown in the drawings are not to be construed as limiting, and those skilled in the art will understand that the present invention can be combined with each other, and when combined, some of the components may be omitted.

Here, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings, but should be construed as meaning and concept consistent with the technical idea disclosed in the present specification.

Therefore, the embodiments described in the present specification and the drawings are only exemplary embodiments of the present invention, and are not intended to represent all of the technical ideas disclosed in the present specification, so that various equivalents It should be understood that water and variations may be present.

310: Contactor-driven power saving circuit 320: Sag detection and drive circuit
322: DC power generator 330: Sag control circuit
332: voltage supply 334: current detector
336: Coil drive current comparator

Claims (7)

A power input unit for supplying an alternating current;
A first capacitor for controlling an alternating current supplied through the power input unit;
A first switch connected to the first capacitor in parallel;
A rectifier circuit unit for converting an AC current transmitted through the first capacitor or the first switch unit into a DC current and outputting the DC current;
A driving coil for magnetizing the fixed core by the DC current;
A second switch part connected in parallel to the first switch part and transmitting an alternating current supplied through the power input part by on / off operation;
A second capacitor connected to a rear end of the second switch unit and controlling an AC current transmitted through the second switch unit;
A DC power generator for generating a DC power using the DC current; And
The second switch unit is turned on when the detected current is equal to or lower than a predetermined first current and the second switch unit is turned off when the detected current is equal to or higher than a predetermined second current, (sag) control circuit;
, ≪ / RTI &
Wherein the first switch unit is turned on at the time of initial startup of the apparatus to transmit an alternating current supplied through the power input unit to the rectifying circuit unit and is turned off when the movable iron core is attached to the fixed iron core. And voltage sag compensating electronic contactor. delete 2. The semiconductor memory device according to claim 1,
A voltage supplier for supplying DC power generated by the DC power generator to the sag control circuit;
A current detector for detecting a current flowing through the drive coil; And
A coil drive current comparator comparing a current detected by the current detector with a predetermined first current and a second current;
And a voltage-sag compensating electromagnetic contactor. The method according to claim 1,
Wherein the first switch unit is a B contact switch which is opened when the first switch unit is closed before being operated. A power input unit for supplying an alternating current;
A first capacitor for controlling an alternating current supplied through the power input unit;
A first switch connected to the first capacitor in parallel;
A rectifier circuit unit for converting an AC current transmitted through the first capacitor or the first switch unit into a DC current and outputting the DC current;
A DC power generator for generating a DC power using the DC current;
A driving coil for magnetizing the fixed core by the DC current; And
A contactor start control circuit which is driven by the DC power supply and turns on the first switch unit when the DC power supply is higher than a predetermined voltage and turns off the first switch unit when the movable iron core is attached to the fixed iron core;
Lt; / RTI >
The contactor start control circuit
A voltage supplier for supplying the direct current power generated by the direct current power generator to the contactor start control circuit; And
A contactor DC power supply comparator for comparing a voltage supplied by said voltage supply with a predetermined voltage;
A power saving and voltage sag compensating electromagnetic contactor. delete 6. The method of claim 5,
Wherein the first switching unit is a Photo Triac. ≪ Desc / Clms Page number 19 >

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