JPH0340195B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to so-called electric rain shutters, electric shutters,
The present invention relates to a load drive device that can be advantageously implemented for forward and reverse rotation of a motor for opening and closing an electric curtain.

BACKGROUND ART FIG. 1 is a front view serving as the background of the present invention and for explaining the prior art. There is one door in the house.
is provided, and a shutter 2 that moves up and down is provided on the outside. This shutter 2 is wound up by a winding means 3, and the winding means 3 is driven by a motor 4.
driven by. This motor 4 is capable of forward and reverse rotation. In connection with the motor 4, an operating circuit block 5 and a relay circuit 6 are provided. The operation circuit block 5 is provided with a lift switch 7 that is operated to raise the shutter 2, a lower switch 8 that is operated to lower the shutter 2, and a stop switch 9 that is operated to stop the shutter 2. It will be done.

In the prior art shown in FIG. 2, in order to rotate the motor 4 in the normal direction to raise the shutter 2, the lift switch 7 is pressed. As a result, the power from the power source 10 is passed from the stop switch 9 in the conductive state to the raise switch 7 and the conductive switch X21 of the relay X2 to excite the relay coil XL1 of the relay X1. As a result, self-holding switch X11 becomes conductive, and the excitation state of relay coil XL1 is self-maintained. By energizing relay coil XL1, relay switch X13 becomes conductive, so that AC power is applied from relay switch X13 to motor 4 via upper limit switch I1, which is conductive. A thermoswitch Th for protecting the motor 4 is connected to the motor 4. In this way, the motor 4 is driven.

When the shutter 2 is fully opened and reaches the upper limit position, the upper limit switch l1 remains closed, thereby de-energizing the motor 4. When motor 4 is stopped, the relay coil of relay
XL1 remains energized and power is wasted.

To release the self-holding state of the relay X1, it is necessary to once operate the stop switch 9 to shut it off.

In this way, motor 4 is stopped and relay
1 is in a self-holding state, even if the lowering switch 8 is turned on to lower the shutter 2, the relay switch X12 of the relay X1 remains cut off. Therefore, relay coil XL2 is demagnetized, and relay switch X2 for self-holding is activated.
2 remains cut off, and relay coil 23 also remains cut off. The lower limit switch l2 shuts off when the shutter 2 descends and reaches the lower limit position,
When the shutter 2 is open even slightly, it is electrically conductive. Even if the lower switch 8 is operated while the motor 4 is stopped, the shutter 2 cannot be lowered, and the stop switch 9 must be operated before the lower switch 8 is operated. The prior art is therefore prone to malfunctions.

Purpose An object of the present invention is to provide a load drive circuit that prevents power waste and has improved operability.

Embodiment FIG. 3 is an electrical circuit diagram of an embodiment of the present invention. Corresponding parts of the above-mentioned prior art are given the same reference numerals. Relay X1 is relay coil XL1
has. Self-holding switch X11 is connected to relay coil XL1 and relay switch X2 of relay X2.
1 and a triax 13 as a switching element of the self-hold release circuit 12 in series. The rising switch 7 is connected to a series circuit consisting of a triax 13 and a self-holding switch X11.
connected in parallel. Load switch X13 of relay X1 connects lines 20 and 25, load current detection means 15, line 14, and upper limit switch l1.
, the normal rotation side terminal 17 of the motor 4, and the thermoswitch Th are connected in series. Self-holding switch X11 and load switch X13 are conductive only while relay coil XL1 is energized. The motor 4 is
When power is supplied to terminal 17, it rotates forward and the shutter 2
is raised and opened, and when power is supplied to the other terminal 18, the shutter 2 is lowered and closed.

Another relay X2 also has a self-holding switch X22 and a load switch X2, similar to relay X1.
23. Current flows through relay coil XL2 via relay switch X12, which shuts off when relay coil XL1 is excited. A line 1 is connected to the motor 4 from the load current detection means 15.
4. Load switch X23 and lower limit switch L2
A current flows through the motor 4, causing the motor 4 to reverse.

The upper limit switch l1 shuts off when the shutter 2 is fully open and at the upper limit position. Lower limit switch l2
is shut off when the shutter 2 is lowered and fully closed.

In the self-hold release circuit 12, the load current detection means 15 connects the line 20 via the stop switch 19.
and the line 14, and the resistor 21
and diodes 22 and 23 connected in series to the resistor 21. Diodes 22, 23
are connected in parallel with mutually opposite polarity. Line 14 is connected to the gate of triac 13 via resistor 24. The resistance value of the resistor 21 is small;
For example, it is about 0.5Ω. Diode 22,2
3 prevents as much as possible an abnormal high voltage from being generated in the resistor 21 when an excessive load current flows. The resistor 24 has a value of, for example, about 100Ω, and ignites the triac 13 to conduct when a normal load current flows.

In order to fully open the shutter 2, the lift switch 7 is operated to temporarily turn it on. As a result, relay coil XL1 of relay X1 is excited, and load switch X13 becomes conductive. As a result, from the line 20 to the line 25, the resistance 2 of the load detection means 15
1, diodes 22, 23, line 24, load switch X13, upper limit switch l1 and terminal 17
A current flows through the motor 4, causing the motor 4 to rotate normally and the shutter 2 to rise. At this time, the triax 13 becomes conductive,
Self-holding switch X11 becomes conductive and the relay coil
XL1 is self-maintained while being energized.

When the shutter 2 rises and reaches the upper limit position, the upper limit switch l1 shuts off. This results in line 2
No load current flows through 0, 25, and 14, and accordingly, the triac 13 is extinguished and the relay coil
XL1 is demagnetized. Self-holding switch X11 is therefore shut off. Thus relay coil XL
1's self-holding is released. In summary, shutters 2
When reaches the upper limit position, the motor 4 is stopped and the self-holding of the relay X1 is released.
Therefore, no further power is wasted.

When the lowering switch 8 is operated to close the shutter 2 and it becomes temporarily conductive, the relay coil XL
2 is excited. This causes the load switch 23
is conductive, line 20, load detection means 15, line 14, load switch X23, lower limit switch l2
Then, power is supplied to the terminal 18 and the motor 4, and the motor 4 rotates in reverse. At this time, the triax 13 is ignited and becomes conductive, and the self-holding switch X22
remains conductive and is self-maintained.

When the shutter 2 reaches the lower limit position, the lower limit switch l
2 is cut off, thereby deenergizing the motor 4. When the load current stops flowing, Triack 1
3 is extinguished, and the self-holding state of relay coil XL2 is released. After the shutter 2 reaches the lower limit position in this way, the motor 4 is deenergized and the self-holding of the relay coil XL2 is released.
No unnecessary power is consumed.

FIG. 4 is an electrical circuit diagram of a self-hold release circuit 12a according to another embodiment of the present invention. In this example,
The load current flows from line 25 to line 14 via primary coil 29 of current transformer 28 . Current transformer 28
The current from the secondary coil 30 is applied to the triac 13 via the resistor 24.

FIG. 5 is an electrical circuit diagram of a self-hold release circuit 12b according to still another embodiment of the present invention. In this embodiment, the load current flows through the resistor 32 and the rectifier circuit 33. The output from the rectifier circuit 33 is the photocoupler 3
The light emitting element 35 of No. 4 is turned on. The light from the light emitting element 35 is received by the photothyristor 36 and conducts. By the photothyristor 36 being conductive, the rectifier circuit 3 is connected from the line 25 to the line 26.
Current flows through 7.

FIG. 6 is an electrical circuit diagram of a self-hold release circuit 12c according to another embodiment of the present invention. In this example,
The load current flows through the primary coil 39 of the current transformer 38. The power from the secondary coil 40 of the current transformer 38 is rectified by a rectifier circuit 41 to light the light emitting element 43 of the photocoupler 42 . The light from the light emitting element 43 is
The light is received by the photothyristor 44. By the photothyristor 44 being conductive, the line 2
The current from 0 is passed through the rectifier circuit 45 to the line 26
guided by.

The present invention is not only used for forward and reverse rotation of a motor, but can also be widely implemented for driving other loads.

Effects According to the present invention, operability is improved, and since self-holding is released after the load is de-energized, wasteful power consumption is prevented.

[Brief explanation of drawings]

FIG. 1 is a simplified front view serving as the basis of the present invention and for explaining the prior art, FIG. 2 is an electrical circuit diagram of the prior art, and FIG. 3 is an electrical circuit diagram of an embodiment of the present invention. FIG. 4, FIG. 5, and FIG. 6 show self-hold release circuits 12a and 12 of other embodiments of the present invention.
12b and 12c are electrical circuit diagrams, respectively. 2...Small shutter, 4...Motor, 7...Up switch, 8...Down switch, 9...Stop switch,
12a, 12b, 12c... self-hold release circuit,
13...triax, 15...load current detection means, X1, X2...relay, XL1, XL2...relay coil, X11, X22...self-holding switch, X13, X23...load switch.

Claims (1)

[Claims] 1. A power source, a relay coil, a self-holding switch connected in series with the relay coil to the power source, and a load switch connected in series to a load and the power source, the relay coil a relay that conducts between the self-holding switch and the load switch only during the excitation by excitation of the relay; an operating switch that is connected to the power supply in series with the relay coil and parallel to the self-holding switch; and a self-holding release circuit. such a self-hold release circuit, comprising means for detecting load current, and a switching element connected in series with the self-hold switch and the relay coil and conducting when the load current is flowing; 1. A load driving device comprising: an operation detection switch connected to a series circuit of a power source and a load switch, and shuts off when the load performs a predetermined operation.