JP2931950B2 - Electromagnet drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC / DC excitation type electromagnet apparatus.

[0002]

2. Description of the Related Art Generally, an electromagnet apparatus comprises a fixed iron core wound with an operating coil and a movable iron core facing the fixed iron core via a gap. When the operating coil is excited, the movable iron core is attracted to the fixed iron core, and the gap is removed. Just move and be adsorbed. In this case, a large suction force is required in the initial stage of suction in which the iron core gap is large, and the suction can be maintained with a small suction force after completion of the suction.

In order to cope with such a characteristic, a main winding for generating most of the attraction force and a sub winding for generating the attraction force required for holding the movable iron core are provided. Is controlled by a switch linked to the movement of the movable iron core (for example, Japanese Patent Application Laid-Open No. 2-207505).

When the operating voltage of the electromagnet device is AC,
As a countermeasure against beat noise during holding, a method of DC excitation using a rectifier is also taken, and an example of such a method is disclosed in Japanese Patent Publication No. 60-12769 shown in FIG.

In FIG. 5, the excitation circuit is an excitation circuit having a main winding M ₁ and a sub winding M ₂ , and generates a large magnetomotive force in the main lacrimal gland M ₁ during suction.

During the holding operation, the rectifier has bridge rectifiers D _{1 to} D ₄ separated by switches. When the AC voltage is applied, the holding operation is performed in the same core by the magnetic flux generated by the sub winding M ₂ . to induce a voltage to the main winding M ₁ that he, by a direct current this voltage is rectified by the bridge rectifier may be a holding operation without beat tones.

The operation when an AC voltage is applied will be described with reference to FIG. When a voltage is applied to the excitation circuit,
The main winding M ₁ is a large rectified current flows, to suck the movable iron core. When the suction process is completed, the disconnecting contact B is opened and one of the AC input terminals of the bridge rectifier is disconnected, so that there is no direct power supply from the commercial power supply to the main winding. When the movable core is attracted, the electromagnet becomes a closed magnetic circuit and operates as a transformer. Here, the primary winding is the sub winding M
₂ and the secondary winding is the main winding M ₁ , but the main winding M ₁
, Diodes D _{1 to} D ₄ of a bridge rectifier are connected in series to form a closed circuit. The excitation required for holding is
By half-wave rectification current flowing through the voltage induced in the main winding M ₁ by the magnetic flux and the electromagnetic induction generated by the sub winding M _2.

[0008]

[SUMMARY OF THE INVENTION The holding operation of the conventional apparatus, the magnetic flux generated by the secondary winding M ₂ is a primary winding, the main winding M ₁ is a secondary winding by electromagnetic induction due to the magnetic flux The voltage induced in the rectifier is half-wave rectified by the diodes D _{1 to} D ₄ and is held by a combined ampere turn with the magnetic flux generated by flowing the half-wave DC current. when you turn off the voltage applied to the winding M _2, the main winding M ₁ is a bridge rectifier D ₁
ＤD ₄ , the electromagnetic energy of the main winding is consumed by the flywheel circuits of the bridge rectifiers D _{1 to} D ₄ , which has the disadvantage that the open time of the electromagnet is prolonged.

To solve this problem, Japanese Patent Publication No. Sho 60-12770
No. In the technique described in JP, insert switch in series with the main winding M ₁ as shown in FIG. 6, and as shown in FIG. 7, the resistance holding time is in series with the main winding M ₁ r Are described. However, typically electromagnetic device main body are mostly be distant control, since the operation switch 0 is remotely located, it is synchronized with the second switch 0 ₁ operation switch 0 as shown in FIG. 6 On
Or is required complex cabling is to turn off, when in conjunction with disconnecting switch B, since the main winding M ₁ would be disconnected at the time of holding, holding becomes AC excitation of only auxiliary winding M ₂ , Humming, increasing power loss,
There were problems such as an increase in open-circuit voltage.

Further, in the case of FIG. 7, with the time holding loss continuous power at resistor r occurs, the load impedance becomes large when the resistance is seen excessively large from the main winding M _1, open circuit voltage rises If the size is reduced, the flywheel effect cannot be suppressed, and the opening time cannot be shortened.

The problem to be solved by the present invention is to reduce the opening time of the electromagnet without the need for complicated connection with the outside, and without the occurrence of humming noise, an increase in power consumption, and an increase in the open voltage. Is to do.

[0012]

In order to solve the above-mentioned problems, an electromagnet driving device according to the present invention comprises a sub-winding connected to an AC terminal and a cut-off at a set position interlocked with the movement of a movable portion. And a rectifier for inputting AC power supplied through the switch and converting the power to DC, and an electromagnet driving device having a main winding connected to the DC terminal of the rectifier, the voltage applied to the AC terminal. And a switch element control means for receiving a DC terminal voltage of the rectifier and the timing signal and outputting a signal for controlling a switch element; and A switch element connected in series to the winding and driven by the switch element control means.

[0013]

FIG. 1 is a circuit diagram showing the basic configuration of the present invention, and FIG. 2 is an equivalent circuit diagram when the switch 3 is turned off and the electromagnet is held.

In FIGS. 1 and 2, AC power supply terminals A ₁ -A
_When a voltage is applied to the switch ₂ , an alternating current is applied to the sub winding M ₂ , and a full-wave DC voltage is applied to the bridge rectifier 4 at the same time. turned on, DC voltage is applied to the main winding M ₁ 6, the movable iron core is attracted. The switch 3 is a switch linked to the movement of the movable core, and is turned off in the holding state.
The switch 3 is one of the AC terminals of the bridge rectifier 4 becomes off are disconnected, resulting in the entire electromagnet device takes the form of FIG. 2, the main winding M ₁ 6 is the AC power supply terminal A ₁ -A ₂ There is no electrical coupling. However main winding M ₁ and the sub winding M ₂ are arranged in the same iron core, the electromagnetic induction action of the alternating magnetic flux generated by the auxiliary winding M _2, the main winding M _1, auxiliary winding M ₂ and main winding M
An AC voltage corresponding to the turns ratio of ₁ is generated. In other words, the main winding M ₁ by flowing a large current becomes a load on startup, but to generate a large force, holding time acts become the secondary winding of the transformer, the auxiliary winding M ₂ Main winding M
An AC voltage corresponding to the turns ratio of ₁ is generated.

The timing generating means 2 includes an AC power supply terminal A
Detecting a ₁ -A ₂ voltage, convey a signal synchronized with the voltage phase to the switching element control unit 5. Switching element control means 5, the signal and the timing generating means 2 detects the voltage generated in the main winding M ₁ 6, drives the switching element 7.

The main winding M ₁ 6, the switch element 7, a closed loop with a bridge rectifier 4 becomes shaped configured, A ₁ 'although current flows through the main winding M ₁ when positive, A _2' is When the value is positive, no current flows because the direction of the bridge rectifier is reversed. In this way the holding state is held and the alternating current flowing through the auxiliary winding M _2, synthetically ampere-turns of the dc current of the half-wave flowing through the main winding M _1.

In this state, the AC power supply terminals A ₁ -A ₂
When the voltage between turns off immediately flux by the sub winding M ₂ 1 no longer, at the same time the timing generator 2 stops signal to the switch element control unit 5. Transient voltage in the main winding M ₁ 6 is generated by the energy, the main winding M
_Although current continues to flow in the closed circuit of the switch element 6, the switch element 7, and the bridge rectifier 4, the switch element control means 5 turns off the switch element 7 because the signal from the timing generation means stops.

[0018] Therefore, the circuit of the main circuit M ₁ 6 will be an open,
When the current becomes zero, the movable iron core opens immediately.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments.

FIG. 3 shows a specific embodiment of the present invention.
Indicates the waveform of each part. 3 and 4, when the voltage to the AC power supply terminal A ₁ -A ₂ is applied to the sub winding M ₂ 1 is
An alternating current is applied, and at the same time, a full-wave DC voltage is applied to the bridge rectifier 4. The timing generation circuit 2 uses A ₂
When the voltage on the side becomes positive and exceeds the voltage determined by the Zener diode 12, the transistor 15 is turned on. When the transistor 15 is turned on, the diode 10, the resistor 14,
A current flows through the photocoupler (light emitting side) 17, and the signal is transmitted to the insulated light receiving side 1 provided in the switch element control circuit 5.
7 '. Since a full-wave DC voltage is applied to the DC terminal of the bridge rectifier 4 to which the switch element control circuit 5 is connected, the photocoupler 17 ′ is turned on when A ₂ is a positive half cycle, and the capacitor is connected through the resistor 16. 18 is charged. When A ₂ is a negative half cycle, the signal from the timing generation circuit 2 disappears, but the Zener diode 20 conducts and charges the capacitor 18.

The switching element 7 is a voltage-operated transistor, and its gate is connected to one end of the capacitor 18. Therefore, when the capacitor voltage rises to the operating voltage of the switching element, the switching element 7 is turned on, and a current flows through the main winding 6. Since the main winding 6 is designed to have a lower impedance than the sub winding 1, a large current flows and the movable core is attracted. The switch 3 is a switch linked to the movable iron core, is connected to one of the AC sides of the bridge rectifier 4, and has a configuration in which the switch 3 is turned off in the holding state. When the switch 3 is turned off, the DC output of the bridge rectifier 4 becomes zero,
The current flowing through the main winding 6 becomes zero.

However, the main winding 6 is arranged in the same iron core as the sub winding 1, and an AC voltage is generated in the main winding by an alternating magnetic field generated by the sub winding. This voltage is a voltage determined by the turns ratio between the sub winding 1 and the main winding 6, and is usually about several tenths to one hundredth of the full-wave rectified voltage at the time of startup due to the balance with the holding current. Is set to
The main winding 6 is a series closed circuit of the switch element 7 and the bridge rectifier 4, and the switch element control circuit 5 is connected in parallel with the bridge rectifier 4.

Here, when A ₂ ′ of the main winding 6 becomes positive, a reverse voltage is applied to the bridge rectifier 4. At this time, the timing generation circuit 2 determines the direction of the diode 10 so as to transmit a signal to the photocoupler 17 '. Thus, the capacitor 18 is charged through the resistor 16 and the switch element 7 is maintained in the ON state.
Next, when A ₁ ′ of the main winding 6 becomes positive, since the switch element 7 is kept on, the bridge rectifier 4
, A forward voltage is applied to form a closed circuit, and the main winding 6
Current flows through In this case, the charge of the capacitor 18 is gradually discharged through the resistor 19, since the A ₂ 'of the main winding becomes positive again in the next cycle, the capacitor 1
8 is also charged again. In this way, the switching element 7 is continuously maintained in the ON state, and an alternating current flows through the sub winding 1 and a half-wave DC current flows through the main winding 6, and the switching element 7 is movable by the combined ampere-turn. Hold the iron core. In this circuit configuration, when the voltage of the AC power supply terminals A ₁ -A ₂ disappears, the energy of the sub winding 1 is absorbed by the surge absorbing element 8. On the other hand, since the energy of the main winding 6 is applied to the gate of the switch element 7 through the diode 22 and the Zener diode 20, the switch element 7 is kept on even when the voltage of the AC power supply terminals A ₁ -A ₂ is lost. The closed circuit remains formed. This closed circuit is the so-called flywheel circuit, where energy is absorbed.

While this closed circuit is formed, a current flows through the main winding 6 to keep holding the movable iron core. However, when the voltage is absorbed below the voltage set by the Zener diode 20, the switching element 7 There is no signal to the gate. Therefore, the switch element 7 is turned off, the current of the main winding 6 becomes zero, and the movable iron core is immediately opened.

As described above, while the voltage is applied to the AC power supply terminals A ₁ -A ₂ , the switch element 7 is kept on by the signal of the timing generation circuit 2 to hold the movable core, and the voltage disappears. By quickly absorbing the energy of the main winding and turning off the switch element 7, the movable core can be opened in a short time.

In FIG. 3, the Zener diode 21 is an element for protecting the gate terminal of the switch element 7.

[0027]

As described above, according to the present invention, a timing generating means for detecting a voltage applied to an AC terminal and generating a timing signal synchronized with the voltage phase, a DC terminal voltage of a rectifier, and By providing a switch element control means for inputting a timing signal and outputting a signal for controlling the switch element, and a switch element connected in series to the main winding and driven by the switch element control means,
Able to shorten the opening time of the electromagnet without the need for complicated wiring to the outside, and to shorten the opening time of the electromagnet without impairing basic characteristics such as generation of beat noise, increased power consumption, and increased open voltage. Can be.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a basic configuration of the present invention.

FIG. 2 is an equivalent circuit diagram when a switch is turned off and an electromagnet is held.

FIG. 3 is a circuit diagram showing a specific embodiment of the present invention.

4 is an operation waveform diagram of each unit in FIG.

FIG. 5 is a circuit diagram showing a configuration of a conventional electromagnet driving device.

FIG. 6 is a circuit diagram showing a configuration of a conventional electromagnet driving device.

FIG. 7 is a circuit diagram showing a configuration of a conventional electromagnet driving device.

[Explanation of symbols]

1 sub winding, 2 timing generation circuit, 3 switch,
4 Bridge rectifier, 5 switch element control means, 6 main winding, 7 switch element, 8, 9 surge absorption element, 1
0 diode, 11, 13, 14, 16, 19 resistor, 12, 20, 21 Zener diode, 15 transistor, 17, 17 'photocoupler, 18 capacitor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-65360 (JP, A) JP-A-2-207505 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01F 7/18

Claims (1)

(57) [Claims] 1. A sub winding connected to an AC terminal, a switch that is turned off at a set position in conjunction with the movement of a movable part, and an AC power supplied through the switch is input and converted to DC. A rectifier, and a timing generator for detecting a voltage applied to the AC terminal and generating a timing signal synchronized with the voltage phase in an electromagnet driving device having a main winding connected to a DC terminal of the rectifier. A switch element control means for inputting a DC terminal voltage of the rectifier and the timing signal and outputting a signal for controlling a switch element, and a switch element connected in series to the main winding and driven by the switch element control means An electromagnet drive device comprising: