JPS6337603A - Control circuit for exciting electromagnetic coil - Google Patents

Abstract

PURPOSE:To supply currents having a waveform capable of positively driving an electromagnetic coil strongly without using a capacitor having large capacitance by full-wave rectifying supply currents to the electromagnetic coil. CONSTITUTION:When a switch 1 is changed over so that C2 is closed, currents flow through a diode 8 and a relay coil 3 in order to charge a capacitor 2 at positive and negative voltage because the directions of a diode 7 and a diode 6 are opposed. When the currents reach a fixed value (a relay operation release current value) or more, a normally open contact C3 is closed by the working of a relay. Currents flow in the left direction from the right direction in output terminals Out1 and Out2 for a full-wave rectifying bridge circuit through the normally open contact C3 and a normally closed contact C5 in a magnetic coil 5 at that time. When the direction of the currents represents the forward direction, the currents have a full-wave rectified waveform. Accordingly, an armature 24 for a solenoid valve is pulled up by the magnetic force of the magnetic coil and the force of a permanent magnet, and attracted and held.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control circuit for excitation of an electromagnetic coil used in an electromagnetic valve, a solenoid, a relay, an electromagnetic switch, or the like.

[Conventional technology]

Recently, in solenoid valves, permanent magnets have been used to hold the ferromagnetic armature in the open or closed position of the valve in order to reduce power consumption and electromagnetic noise of the solenoid coil. It became so. That is, the solenoid valve, as shown in FIGS. 5A and 5B,
A camp 22 made of a ferromagnetic material and an annular plate 23 are provided at the upper and lower ends of a frame 21 made of a magnetic material, and an armature 24 made of a ferromagnetic material pressed by a spring 26 is moved up and down in the center of the frame 21. possible. Further, an annular permanent magnet 25 is provided between the frame 21 and the plate 23, and an electromagnetic coil 27 is provided around the armature within the frame 21.

Armature 24 is stably held in one of two positions: That is, the valve closed state is a position where the valve is pressed and held by the spring 26, as shown in FIG. 5A, and in this case, the valve seat 28 is closed. On the other hand,
The valve open state is a position held by the magnetic field of the permanent magnet 25, as shown in FIG. 5B, in which case the valve seat 28 is open and fluid, such as air, can flow as shown by the arrow.

The force for moving the armature 24 between the two states described above is achieved by energizing the electromagnetic coil 27. For example, in the closed state of the valve shown in FIG. 25 becomes larger than the pressing force of the spring 26, and as a result, the armature 24 rises to the state shown in FIG. (This state is maintained by the n force. In other words, in FIG. 5B, a magnetic circuit is formed by the permanent magnet 25 in the loop formed by the magnetic elements 21-25-23-24-22, Even if the current is removed, the magnetic circuit is maintained.

Furthermore, in the valve open state shown in FIG. 5B, when a current is passed through the electromagnetic coil 27 in the opposite direction to that described above, a magnetic field is generated in the opposite direction to the magnetic field of the permanent magnet 25. An anti-+8 magnetic force is generated with respect to the magnetic field, and in combination with the pressure of the spring 26, the armature 24 is separated from the cap 22.

Therefore, the armature 24 descends and returns to the state shown in FIG. 5A. In this case, since there is a gap between the camp 22 and the armature 24, when the electromagnetic coil 27 loses current, the magnetic circuit by the permanent magnet 25 described above is not formed.

The circuits shown in FIGS. 6 and 8 were previously devised by the present inventor as the most improved conventional electromagnetic coil excitation control circuits for operating this electromagnetic valve.

Details of these circuits will be explained below with reference to FIGS. 6 and 8.

6, 105 is an electromagnetic coil to which a current controlled by the electromagnetic coil excitation control circuit is supplied, 120 is an AC power supply, 103 is a relay coil that operates the relay contact 103', and 103' is a positive current applied to the electromagnetic coil. 104 is a relay contact 104' that closes a circuit that supplies
104' is a relay contact that closes the circuit that supplies negative current to the electromagnetic coil, 106
, 107, 108, and 109 are rectifying diodes, 101 is a selection switch for selecting the direction of the current supplied to the electromagnetic coil, and 102 is the relay contact 10.
Each of 3' and 104' is a capacitor that defines the time when the capacitor is closed.

The operation of the circuit shown in FIG. 6 will be explained below.

First, a case will be described in which the switch 101 is switched from the position where C1 is closed to the position where C3 is closed. When C1 is closed in switch lot, the lower side of capacitor 102 (in FIG. 6) is charged positively and the switch 101 side is negatively charged by AC type 6g120 and diode 109. At this time, when switch 101 is switched so that C11 is closed, diode 109 and diode 108
Since the direction of
Current flows through 3. When this current exceeds a predetermined value (relay operating open current value), the normally open contact C9 is closed by the action of the relay. At this time, a current as shown in FIG. 7A flows through the electromagnetic coil 105 due to the action of the diode 106. As a result, the armature 24 of the solenoid valve shown in FIG. 5A is pulled up by the magnetic force of the electromagnetic coil and the force of the permanent magnet, and is attracted and held in the position shown in FIG. 5B. When the capacitor 102 is charged in the opposite direction, the current flowing through the relay coil 103 decreases, and eventually falls below the relay operating open current value necessary to close the normally open contact C9, and then returns to the normally open contact C9. Open contact C1 is opened.

Next, turn the switch 101 from the position where 08 is closed to C? When the switch is switched to the closed position, contrary to the above, a current equal to or higher than the relay operation open current value flows through the relay coil 104, so that the normally open contact C3° is closed, and the electromagnetic coil 10
5, a current flows in the opposite direction as shown in FIG. 7B. The electromagnetic force caused by this is the armature 24
The armature 24 is lowered and held in the position shown in FIG. 5A.

In each of the above two cases, the energization time in the electromagnetic coil 105, that is, the time during which the normally open contact C1 or the normally open contact C1° is closed, is the time required for the capacitor 102 to be charged, that is, the time required for the capacitor 102 to be charged.
By adjusting the capacity of the electromagnetic coil, it can be set to the minimum value necessary to ensure reliable operation of the electromagnetic coil.

In this circuit, as shown in FIGS. 7A and 7B, the time is set to correspond to two cycles of the alternating current.

FIG. 8 shows that in the circuit shown in FIG. 6 above, the current waveform shown in FIGS. 7A and 7B is changed more effectively to ensure the operation of the electromagnetic coil. Several improvements have been made to make it more suitable.

First, a capacitor 111 was installed in parallel with the relay coil 103, and a capacitor 110 was installed in parallel with the electromagnetic coil 105 when the normally closed contact C7 shown in FIG. 8 was closed. As a result, when the switch 101 is switched from 07 to C8, the current flowing through the electromagnetic coil 105 has a shape as shown in FIG. 9A.

Next, a resistor 112 is connected in series with the diode 107.

This is because lowering and closing the armature of the solenoid valve does not require as much current as required to raise and hold it. As a result, when the switch 101 is switched from C8 to C7, the current T flowing through the magnetic coil 105 has a shape as shown in FIG. 9B, for example.

In No. 81, as shown by symbol X, when the normally closed contact C0 of the first relay coil 3 is closed, the following (a) or (
Attach one of the elements shown in b).

(a) A two-terminal element whose resistance value decreases non-linearly as the voltage increases, such as a Zener diode, a varistor, or a diode, is connected to the part indicated by the symbol X above. As a result, when the voltage between the terminals of the electromagnetic coil 105 increases to a certain extent, the resistance value of the two-terminal element with the symbol X decreases, and the switch 101 becomes C! When switching from C1 to C1, the increase in the current flowing through the electromagnetic coil is suppressed, resulting in a waveform as shown in FIG. 9C, for example.

(b) Alternatively, if a capacitor is connected to the part marked with the symbol X above, the switch 101 becomes C! When switching from C1 to C1, the current flowing through the electromagnetic coil 105 has a waveform as shown in FIG. 9D.

[Problem that the invention seeks to solve]

However, recently, demands on the driving force of electromagnetic coils have become higher and higher, and electromagnetic coils with even stronger driving force have become necessary. However, there is a limit to the driving force of the electromagnetic coil that can be obtained by the half-wave rectified waveform supplied by the circuit of FIG. 6 as shown in FIG. 7A or FIG. 7B. It has become clear that it is difficult to satisfy the recent demand for strong driving force.

Furthermore, in the circuit shown in FIG. 8, which is an improved version of the circuit shown in FIG. 6, the waveform shown in FIG. To achieve this, a very large capacitance capacitor is required, and from a cost standpoint, it is not realistic to use a circuit like the one shown in Figure 8 under conditions that require such a large driving force. It's gone.

[Means for solving problems]

In the present invention, in order to solve the above-mentioned problem, the current supply line in the conventional circuit shown in FIG. is provided, and a relay contact of the relay coil of each switch line is provided between the electromagnetic coil and the output end of the full-wave rectifier circuit, and the flow through the electromagnetic coil is provided by switching the selection switch. It tries to reverse the direction of the current.

[For production]

When the selection switch is switched to one side, the one switch line is formed, and until the capacitor connected to the switch line is charged, the relay contact of the relay coil of the switch line is connected to the output of the full-wave rectifier circuit. The electromagnetic coil is connected so that current flows in one direction.

When the partial selection switch is switched from the one to the other, the other switch line is formed, and until the capacitor connected to the switch line is charged to the opposite polarity, the 8
The relay contacts of the relay coil of the positive switch line are connected so that the output current of the full-wave rectifier circuit flows through the electromagnetic coil in the opposite direction to that in the above case.

In this way, by switching the selection switch 1, a full-wave rectified current in the positive and midwinter directions flows through the electromagnetic coil for a certain period of time.

〔Example〕

FIG. 1 is a diagram showing a first embodiment of a control circuit for excitation of an electromagnetic coil according to the present invention.

5 is an electromagnetic coil to which a current controlled by the electromagnetic coil excitation control circuit according to the present invention is supplied; 200 is an AC power supply; 3.4 is a relay coil; 3';

4' is the relay contact of relay coil 3.4, 6,7°8.
9.10 and 11 are rectifier diodes, l
2 is a selection switch that selects the direction of the current supplied to the current coil; 2 is a capacitor that defines the time during which each normally closed contact of the relay contacts 3' and 4' is closed;

The operation of the circuit shown in FIG. 1 will be explained below.

First, a case will be described in which the switch 1 is switched from the position where C8 is closed to the position where C8 is closed. When switch 01 is closed, the AC power supply 200 and the diode 9 cause the capacitor 2 to have a positive voltage on the lower side (in FIG. 1).
The switch 1 side is negatively charged. At this time, if switch 1 is switched so that 02 is closed, diode 7
Since the direction of the diode 6 is reversed, current flows through the diode 8 and the relay coil 3 in order to charge the capacitor 2 to the opposite voltage. When this current exceeds a predetermined value (relay operation open current value), the normally closed contact C3 is closed by the action of the relay. At this time, the electromagnetic coil 5 is connected to the output terminals 0utl and 0 of the full-wave rectifier bridge circuit shown in FIG. 1 via the normally closed contact C3 and the normally closed contact CS.
A current flows from ut2 from right to left in FIG. If this direction is the positive direction, this current has a full-wave rectified waveform as shown in FIG. 2A.

This causes the armature 24 of the solenoid valve shown in FIG. 5A to
is pulled up by the magnetic force of this electromagnetic coil and the force of the permanent magnet, and is attracted and held at the position shown in FIG. 5B. When the capacitor 2 is charged in the opposite direction, the current flowing through the relay coil 3 decreases, and eventually falls below the relay operating open current value necessary to close the normally closed contact C1, and then returns to the normally closed contact C1. Closed contact C3 is opened and normally closed contact C4 is closed.

Next, when switch 1 is switched from the position where 02 is closed to the position where 01 is closed, the relay coil 4
When a current equal to or higher than the relay activation current value flows through the normally closed contact C5, the normally closed contact C5 is closed, and the electromagnetic coil 5 is then supplied with the opposite current to the above via the normally closed contact C6 and the normally closed contact C4. A current flows in the direction. This waveform is shown in FIG. 2B.

The resulting electromagnetic force acts in a direction to push down the armature 24, and the armature 24 is lowered and held at the position shown in FIG. 5A.

In each of the above two cases, the energization time in the electromagnetic coil 5, that is, the time during which the normally closed contact C3 or the normally closed contact C6 is closed, is the time required for the capacitor 2 to be charged, that is, the time required for the capacitor 2 to be charged. By adjusting the capacity of the electromagnetic coil, it can be set to the minimum value necessary to ensure reliable operation of the electromagnetic coil. This can eliminate unnecessary power consumption. In this example, the second
As shown in Figures A and 2B, the time is set to correspond to 1.5 cycles of the alternating current.

FIG. 3 is a diagram showing a circuit of a second embodiment of the present invention, and in order to make the drive by the electromagnetic coil in the first embodiment more reliable and powerful,
Several improvements have been made to the current waveform shown in Figure B to make it more effective.

First, as shown in FIG. 3, a capacitor 13 is connected between the outputs 0utl and 0ut2 of the full-wave rectifier bridge circuit.
Connect. This changes switch 1 from 01 to Ct
The current flowing through the electromagnetic coil 5 when the switch is switched to has a waveform as shown in FIG. 4A, and the driving by the electromagnetic coil becomes extremely reliable and powerful.

Next, a resistor 12 is connected in series between the 0ut2 and the normally closed contact C6.
Connect. One of the reasons for connecting this resistor 12 is that in order to lower and close the armature 24 of the electromagnetic valve of this embodiment, it does not require as much current as is required to maintain it in the upward direction. Furthermore, if the current in the opposite direction becomes too large, the electromagnetic coil 5 will cause the permanent magnet 2 to pass through the loop of the magnetic elements 21-25-23-24-22 in FIG. 5B.
This generates a reverse magnetic field that more than cancels the forward magnetic field created by the armature 24, thereby holding the armature 24 in the raised position instead of lowering.

Therefore, the second reason for connecting the resistor 12 is to adjust the value of the current flowing in the opposite direction through the T4 magnetic coil.

Furthermore, as shown in FIG. 3, a two-terminal element X is connected so that it is connected in parallel to the electromagnetic coil 5 when the normally closed contact C5 is closed.

When a capacitor of an appropriate capacity is connected as the two-terminal element X, the current flowing through the electromagnetic coil 5 when the switch 1 is switched from 02 to 01 has a waveform as shown in FIG. 4B. That is, the energization time in the electromagnetic coil can be extended.

Alternatively, as the two-terminal element X, a two-terminal element X, such as a Zener diode, a varistor, a diode, etc., whose resistance value decreases as the terminal voltage increases and has non-linear current increase characteristics, is connected.

At this time, when the switch 1 is switched from Ct to CI, the current flowing through the electromagnetic coil has a waveform as shown in FIG. 4C. Here, the reason for connecting the two-terminal element having the above-mentioned non-linear current increase characteristic is to connect the electromagnetic coil so that the electromagnetic coil generates a magnetic field in the opposite direction to the extent that it cancels the magnetic field due to the permanent magnet 25 in FIG. 5B. This is to adjust the current value flowing through the coil 5. With only resistor 12, the second
The wave height of the entire output waveform of the full-wave rectifier circuit as shown in Figure B becomes small, and the rise of the current waveform becomes very gentle. The current flowing through the electromagnetic coil can be adjusted not only by connecting the resistor 12 in series, but also by connecting a two-terminal element X having the above characteristics in parallel to the electromagnetic coil 5, as shown in FIG. 4C. A waveform with good rising characteristics and a small wave height can be obtained, and driving by the electromagnetic coil can be made very reliable.

〔Effect of the invention〕

By making the current supplied to the electromagnetic coil full-wave rectified, it is possible to supply a current with a waveform that enables reliable and powerful drive of the electromagnetic coil without using a large capacitor. became.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a first embodiment of the present invention, and FIGS. 2A and 2B are diagrams in which the selection switch l is switched from one to the other or from the other to one in the circuit of FIG. 1, respectively. Figure 3 is a diagram showing the circuit of the second embodiment of the present invention (only around the electromagnetic coil); Figure 4A is a diagram showing the current flowing through the electromagnetic coil; FIG. 4B is a diagram showing the current flowing through the electromagnetic coil when the normally open contact C3 is closed, and FIG. 4B is a diagram showing the current flowing through the electromagnetic coil when the capacitor is connected as the two-terminal element X in the circuit of FIG.
FIG. 4C is a diagram showing the current flowing through the electromagnetic coil when a diode, varistor, or Zener diode is connected as the two-terminal element 5A is a sectional view showing the solenoid valve in a closed state, FIG. 5B is a diagram showing an open state, FIG. 6 is a diagram showing an example of a conventional electromagnetic coil excitation control circuit, and FIG. Figure 7A is a diagram showing the current flowing through the electromagnetic coil when contact C3 of switch lot is closed in the circuit of Figure 6, and Figure 7B is a diagram showing the current flowing through the electromagnetic coil when contact C1 of switch 101 is closed. FIG. 8 is a diagram showing another example of a conventional electromagnetic coil excitation control circuit. FIG. 9A is a diagram showing the current of the electromagnetic coil when contact C3 of switch 101 is closed in the circuit of FIG. 8. Figure 9B shows the current flowing through the circuit of Figure 8 when the two-terminal element X is not connected and the contact C1 of the switch 101 is closed!
FIG. 9C, a diagram showing the current flowing through the magnetic coil, shows what happens when a Zener diode, varistor, or diode is connected as the two-terminal element X in the circuit of FIG.
FIG. 9D is a diagram showing the current flowing through the electromagnetic coil when the contact C1 of the switch 101 is closed. In the circuit of FIG. 8, when a capacitor is connected as the two-terminal element It is a figure which shows the electric current which flows through an electromagnetic coil when it closes. (Explanation of symbols) 1... Selection switch, 2.13... Capacitor, 3.4... Relay coil, 3', 4'... Relay contact, 5... Electromagnetic coil, 6.7 , 8.9, 10.11... diode, 12.
...Resistance,
0utl, 0ut2... Output end of full wave rectifier circuit, 2
DESCRIPTION OF SYMBOLS 1... Frame, 22... Cap, 23... Plate, 24... Armature, 25... Permanent magnet, 26... Spring, 27... Electromagnetic coil, 28... Valve seat , 101...Switch, 102...Capacitor, 103, 104...Relay, 103', 104'...Relay contact, 105
... Electromagnetic coil, 106, 107.108.109 ... Diode,
110.111... Capacitor, 112.119... Resistor, 120... AC power supply.

Claims (1)

[Claims] 1. A capacitor (2) whose one end is connected to a selection switch (1), a first relay coil (3), a first diode ( 8)
, and a first switch line formed by series connection of the capacitor (2) and connected in parallel to the AC power source (200), and a second relay coil (4) by selection of the other of the selection switch (1). ), the second diode (
9), and a second switch line formed by series connection of the capacitor (2) and connected in parallel to the AC power source (200), the second diode (9) being connected to the AC power source (200). 200) while the first diode (
8) and a second switch line connected with a polarity opposite to that of the electromagnetic coil (5). A full-wave rectifier circuit that inputs an AC power output and supplies the output to the electromagnetic coil (5). and a relay contact of the relay coil of the switch line is provided between the output end of the full-wave rectifier circuit and the input end of the electromagnetic coil, and the current flowing through the electromagnetic coil is reversed by switching the selection switch (1). Control circuit for excitation of the electromagnetic coil. 2. A normally closed contact (C_5) of the first relay coil (3), which connects one end (Out1) of the output of the full-wave rectifier circuit to one end of the electromagnetic coil (5), and A normally closed contact (C_4) of the second relay coil (4) connects one end (Out1) of the output of the rectifier circuit to the other end of the electromagnetic coil (5), and a normally closed contact (C_4) of the output of the full-wave rectifier circuit. A normally open contact (C_6) of the first relay coil (3) whose other end (Out2) is connected to the one end of the electromagnetic coil (5), the other end (Out2) of the output of the full-wave rectifier circuit ) of the second relay coil (4), which is connected to the other end of the electromagnetic coil (5).
_3) The electromagnetic coil excitation control circuit according to claim 1, comprising: 3. Both ends of the output of the full-wave rectifier circuit (Out1, Out
2) A control circuit for excitation of an electromagnetic coil according to claim 1 or 2, wherein a capacitor (13) is connected to the electromagnetic coil excitation control circuit. 4. The electromagnetic device according to any one of claims 1 to 3, wherein a resistor (12) is connected between one end (Out1) of the output of the full-wave rectifier circuit and the normally open contact (C_6). Control circuit for coil excitation. 5. The other end of the electromagnetic coil and the normally closed contact (C_4)
A control circuit for excitation of an electromagnetic coil according to any one of claims 1 to 4, wherein a two-terminal element (X) having a non-linear current increase characteristic as the terminal voltage rises is connected between the two terminals. . 6. The electromagnetic coil excitation control circuit according to claim 5, wherein the two-terminal element (X) is a Zener diode. 7. The electromagnetic coil excitation control circuit according to claim 5, wherein the two-terminal element (X) is a varistor. 8. The electromagnetic coil excitation control circuit according to claim 5, wherein the two-terminal element (X) is a diode. 9. The other end of the electromagnetic coil and the normally closed contact (C_4)
Claims 1 to 2 in which a capacitor is connected between
The electromagnetic coil excitation control circuit according to any one of Item 4.