JPS59200402A - Ac electromagnet apparatus - Google Patents

Abstract

PURPOSE:To obtaina compact and highly reliable apparatus that is capable of lessening a loss by accomplishing the connection in such a manner that a capacitor and two rectifier circuits share an entire voltage after the core magnetic attraction. CONSTITUTION:Two normally-closed contacts 6a and 6b open when a movable core is magnetically attracted to a fixed core or immediately before completion of the magnetic attraction. Thereupon, this circuit comes to a state wherein operating coils 1a and 1b are respectively connected in series to DC terminals of two single-phase bridge rectifier circuits 3a and 3b, that is, the operating coils 1a and 1b are conncted in series by means of two circuits, R a1 1a d1 7 a2 1b d2 S and S b2 1b c2 7 b1 1a c1 R, and AC terminals of the rectifier circuits 3a and 3b are connected in series with a capacitor 7 interposed therebetween. Therefore, the AC voltage applied to the R and S terminals is shared by the capacitor 7 and two split operating coils 1a and 1b, and the voltage applied to each of the operating coils 1a and 1b is less than a half of that at the time of the magnetic attraction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an AC electromagnet device used in an electric appliance using a single-phase AC power source as a control power source.

[Prior art and its problems]

Electromagnetic devices generally used in electrical appliances include a fixed core around which an operating coil is wound, and a movable core that faces the fixed core through a gap.When the operating coil is energized, the movable core is attracted to the fixed core by approximately the length of the gap. , the moving stroke of the movable core at this time is used as the operating stroke of the contact. By the way, when this electromagnet device is operated with a commonly available single-phase AC power source, when AC current flows through the operating coil, iron loss occurs due to AC magnetic flux in the iron core, so electric iron plates were laminated to reduce this. Although an iron core is used, it is not possible to completely eliminate iron loss. Also,
Kumadori coils are used to maintain the attractive force of the iron core at the zero current point and to reduce the undulation, but this has the disadvantage that this loss cannot be ignored, and on top of the laminated building,
The drawback is that it requires high material costs and man-hours. Furthermore, the control power source for electromagnet devices is AC.

Regardless of the direct current, there is always a large gap between the fixed core and the movable core, and the movable core usually carries the load that it must drive, so when the fixed core draws this load, a large amperage is required. , a large current must be passed through the operating coil. However, once the movable core is attracted, the air gap almost disappears and the core forms an almost complete magnetic circuit, so the attractive force between the fixed core and the movable core increases, and this is maintained with a small coil current. be able to. From this point of view, an AC electromagnet device as shown in FIG. 1 or 2 is known, in which a DC current obtained by rectifying an AC power supply is applied to an operating coil of an electromagnet section including an iron core and an operating coil.

In FIG. 1, an operating coil 1 is connected to a DC terminal of a single-phase bridge rectifier circuit through a parallel circuit of a normally closed contact 6 and a resistor 2, and an AC terminal of this rectifier circuit 3 is connected to an AC power supply through a switch 4. 5. This electromagnetic device is
When the cup switch 4 is closed, the AC power source 5 is rectified by the rectifier circuit 3, and a DC current flows through the operating coil 1 to attract the movable iron core. Here, the normally closed contact 6 opens when or just before the movable core is attracted to the fixed core, and inserts the resistor 2 in series with the operating coil 1. With this configuration, direct current flows through the operating coil, so the iron loss can be removed from the core, and the laminated core is made of solid iron such as mild steel.
Material costs and man-hours can be saved by excluding the Kumadori Sikoil. Furthermore, after the movable core is attracted, a resistor is inserted to reduce the coil current, so the copper loss of the operating coil is small and the coil itself can be made smaller. However, in this case, a large resistor is required as the resistor 2 to suppress the coil current, and this loss becomes a problem.

In Figure 2, a parallel circuit of a non-polar capacitor 7 and a normally closed contact 6 is connected in series to the AC terminal of a single-phase bridge rectifier circuit 3.
It is connected to an AC power source 5 via a switch 4. The operating coil 1 is directly connected to the DC terminal of the rectifier circuit 3. When the switch 4 is closed, this electromagnetic device causes the rectifier circuit 3 to
The rectified DC current flows through the operating coil 1, and the fixed iron core attracts the movable iron core. When the movable iron core is attracted to the fixed iron core, or just before that, the normally closed contact 6 opens, the capacitor 7 is inserted in series with the AC terminal of the rectifier circuit 3, and the current flowing through the operating coil 1 is reduced. With this configuration, there is no loss due to alternating current as in the one shown in Figure 1, and there is no loss due to the capacitor. 4 has a short lifespan. Furthermore, since a capacitor with a high withstand voltage, a large capacitance, and therefore a large external shape is attached to share the power supply voltage, the device becomes large in size.

[Purpose of the invention]

It is an object of the present invention to eliminate the above-mentioned drawbacks and provide an AC electromagnet device that has low loss, is small in size, and has high reliability.

[Key points of the invention]

The present invention provides two operating coils that are wound around the same fixed iron core and attracts the movable iron core, two single-phase bridge rectifier circuits in which these operating coils are connected to their DC terminals, and each of these two rectifier circuits. A capacitor connected between one AC terminal and a contact that operates when the movable iron core is attracted are provided, and the operation of this contact switches the connection of the rectifier circuit, and the operation coil is connected to the movable iron core. This is an AC electromagnet device in which the rectifier circuit receives the full voltage when attracting the iron core, and the capacitor and the two rectifier circuits are connected so as to share the total voltage after the iron core is attracted. Therefore, a core suction extra-large current flows through the operation coil to reliably attract the movable core, and after the core is attracted, the current is small enough to hold the attracted core, which saves power and reduces the capacity of the operation coil and rectifier circuit diode. is being transformed. Since the capacitor that shares the applied voltage is directly connected with the two rectifier circuits, the shared voltage is relatively low.Moreover, depending on the capacitance of this capacitor, the current ratio of the operating coil during and after the attraction can be adjusted arbitrarily. The contact is preferably a normally closed contact that works with the movable core or a time-limited normally closed contact that is activated by the current flowing through the circuit when the core is attracted, and is activated when the power is turned on and closes only when the core is attracted. Reliability is improved by using normally open one-shot contacts adjusted in this way.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described in detail based on the drawings. 3 and 4 are connection diagrams showing different embodiments of the present invention, respectively.

In FIG. 3, two operating coils la and lb wound around the same fixed core (not shown) are a single-phase bridge rectifier circuit 3a consisting of diodes al and b1+el+dl, and a single-phase bridge rectifier circuit consisting of diodes a2*t)2+C2+d2, respectively. It is connected to the DC terminal 3b.

The DC terminals of these two rectifier circuits 3a, 3b are connected to each other through normally closed contacts 6a, 6b, respectively. Also, two rectifier circuits 3a.

The AC terminals 3b are connected in series with the capacitor 7 in between, and both ends thereof are connected to power supply terminals R and S.

Here, when a single-phase AC voltage is applied to the power terminals R and S, current flows through the following four circuits: 1a - contact 6b - diode d2 - 3 terminal one contact 6a - coil xbL - diode - drawer 2 - S terminal (C)...S terminal - diode b2 - coil 1b - contact 6b - diode (!1 - R terminal ( D)...S terminal - diode b2 - contact 6a - coil 1a - diode c1 fl terminal These four circuits are connected to a circuit in which the two operating coils Ia and lb are connected in parallel, and the diode al l b21 C
In a state where one single-phase bridge rectifier circuit consisting of 1+d2 is supplying DC current, the entire voltage of the power supply is applied to this one rectifier circuit, so the operating coil la.

A large core attraction current flows through 1b. Then, the two normally closed contacts 6a and 6b flip when the movable iron core is attracted to the fixed iron core or just before it is attracted, and this circuit connects the operating coils to the DC terminals of the two single-phase bridge rectifier circuits 3a and 3b, respectively. la and lb are connected in series, that is, fl −+ al −+ l B−+ dl →7−
+ C2-+1b-+ d 2-+ S circuit and S-4
The operating coils la and lb are connected in series in the circuit b2→lb-+c2→7→b1→1a→C1→R, and the AC terminals of the rectifier circuits 3a and 3b are connected with a capacitor 7 between them.
They are connected in series by sandwiching them. Therefore R,
The AC voltage applied to the S terminal is divided into two operating coils 1&lb and capacitor 7, and the voltage applied to each operating coil la and lb is half the voltage applied to the core suction. The value is determined by the capacitance of the capacitor 7. Therefore, the current flowing through each operating coil is reduced to less than half of the time when the core is attracted, and is reduced to a small current that is sufficient to hold the attracted core. The two operating coils la and lb each have a diode al
1) Single-phase bridge rectifier circuit 3a consisting of 1 + cl * di and diodes a2, b2 y C2 *
d2, and the AC terminals of these two rectifier circuits 3a, 3b are connected in series with a capacitor 7 in between.
The point that both ends thereof are connected to power supply terminals R and S is similar to the embodiment shown in FIG. However, in this embodiment, the connection point between the rectifier circuit 3a and the capacitor 7 is connected to the power supply terminal R via the normally closed contact 6a, and the DC terminal of the rectifier circuit 3b has two diodes 8 and 9 connected in series. is connected so that a current flows in the same direction as the rectifier circuit 3b, and the connection point between these two diodes 8.9 is connected to the power supply terminal R. One AC terminal of the rectifier circuit 3b is a normally closed contact 6
It is connected to the power supply terminal S via b.

When a single-phase AC voltage is applied to power terminals R and S, the following (E
), (F), (G), and (H).

(E)...R terminal-contact 6a-diode doro 1-coil la-diode e1-8 terminal (F)...S terminal-diode doro1-coil 1a-diode di-contact 6&-R terminal CG)...R terminal - Diode 8 - Coil lb - Diode d2 - Contact 6b - 8 terminal (H) S terminal - Contact 6b - Diode b2 - Coil lb - Diode 9 - R terminal These four circuits are the top, diode a1+bl+cl+dl
A single-phase bridge rectifier circuit 3a consisting of a diode b2,
8. The two operating coils la and lb- connected to the respective DC terminals of another single-phase bridge rectifier circuit consisting of d2 and 9 are connected in parallel when viewed from the power supply terminals R and S, respectively. Since the full voltage of the AC power supply is applied to the AC terminals of each rectifier circuit, the operation coil la,
A large direct current flows through lb, attracting the movable iron core. As a result, when the two contacts 6a and 6b open, R-
+ 8-) 1 b -+ c 2-+ 7 →b 1→
l B −+ A circuit consisting of C1→S and S−+al−+
A circuit of 1a-+d1-+7→a2→1b→9→R is formed, and the operating coils la and lb are connected in series with the capacitor 7 in between. Therefore, the applied AC voltage is applied to the operating coils la and lb, which are divided into two.
However, the voltage applied to each of the operating coils la and lb must be less than half of the voltage applied to the core suction, and its value is determined by the capacitance of the capacitor 7. Therefore, the current flowing through each operating coil is reduced to less than half of the time when the core is attracted, and is reduced to a small current sufficient to hold the attracted core.

In the above embodiments, the normally closed contacts 6a and 6b are mechanical contacts that operate in conjunction with the movable core, but these normally closed contacts are time-limited normally operated contacts that are activated by the current that flows when the core is attracted. It is best to use a closed contact, or the reliability will be further improved if this is a one-shot normally open contact that operates instantly when the power is turned on and closes only when the core is attracted. These contacts may be formed by non-contact switches.

〔Effect of the invention〕

As described above, in the AC electromagnet device according to the present invention, since the electromagnet section allows the DC current rectified by the single-phase bridge rectifier circuit to flow through the operating coil, there is no occurrence of sagging, and there is no problem with dark circles. The structure is simple because no coil is required. In addition, the operating coils are two operating coils wound around the same fixed core, and these two operating coils are each connected to the DC terminal of a single-phase bridge rectifier circuit, and when attracting the core, the operating coils are connected in parallel. A large core suction current is applied by applying the full voltage of the AC power supply through the rectifier circuit. After the core is attracted, a capacitor is inserted between the two operating coils and connected in series, and the AC power source is The total voltage is divided between two operating coils and a capacitor, reducing the direct current of the operating coil to a small current that is sufficient to hold the attracted iron core. Therefore, power consumption is small;
The operation coil and rectifier circuit diodes may have small capacities.

Also, since the capacitor shares the voltage with the two operating coils, the withstand voltage can be relatively low. However, the capacitance of this capacitor determines the current when the operating coil holds the iron core attracted by it. This has the effect that the ratio between the current during core attraction and the current for holding the attraction core can be arbitrarily selected.

[Brief explanation of drawings]

1 and 2 are wiring diagrams showing the main parts of a conventional AC electromagnet device, respectively, and FIGS. 3 and 4 are wiring diagrams showing the main parts of different embodiments of the AC electromagnet device according to the present invention, respectively. . la, lb......operating coil, 3a, 3b.
...Single-phase bridge rectifier circuit, 6a, 6b...
... Normally closed contact, 7 ... Capacitor, 8, 9.
·····diode. f 1 figure f z figure zu 3 figure f 4 figure

Claims (1)

[Claims] 1) An operating coil that is wound around the same fixed core and is divided into two that attracts the movable core, two single-phase bridge rectifier circuits that connect these operating coils to their DC terminals, and these two rectifier circuits. and a contact that opens in response to the adsorption operation of the movable iron core, and when the contact is closed, the two divided operating coils are connected in parallel. An AC electromagnet device characterized in that the operating coil divided into two is connected in series with the capacitor when the contact is opened.