JPS6156647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a circuit advantageously used for controlling loads such as lighting lights and ventilation fans.

Conventionally, a switch is connected in series with the lamp, and when the switch is shut off, the lamp is immediately de-energized. For example, when such lighting lights are installed on the stairs or hallways of a building, it is convenient for people passing by if they remain lit for a predetermined period of time after the switch is operated to turn them off. Dew.

Prior art techniques for solving such problems are shown in, for example, Japanese Utility Model Applications No. 50-91454 and No. 50-113331. In this prior art, the load current is detected by a current transformer connected in series with the switch, a capacitor of a discharge time constant circuit is charged, and a semiconductor switching element is connected in parallel to the series circuit of the switch and the current transformer. This semiconductor switching element is connected to
It becomes conductive when the output of the discharge time constant circuit is equal to or higher than a predetermined value. Therefore, after the switch is shut off, the load is further energized only during the period when the semiconductor switching element is conducting due to the action of the discharge time constant circuit.

Such prior art includes only a single switch, and cannot control the load on/off from multiple locations.

An object of the present invention is to provide a load control circuit that continues to energize a load for a predetermined period of time after each of a plurality of switches is operated.

The present invention includes: an AC power source 1; a load 2 connected in series to one output end of the AC power source; a primary coil 16 connected in series to the load 2;
A current transformer CT having a secondary coil 17 magnetically coupled to this primary coil, a first common contact 6 connected to a terminal of the primary coil 16 on the opposite side to the load 2, and this first common contact. 6
a first three-way changeover switch 3 having first and second individual contacts 7, 8 which are selectively switched manually to conduction; and an output end of the AC power supply 1 opposite to the load 2; A second common contact 9 is connected to the second common contact 9, and a third common contact 9 is selectively switched into conduction by manual operation to the second common contact 9 and is connected to the first and second individual contacts 7, 8, respectively. a second three-way changeover switch 5 having fourth individual contacts 10, 11; a second bidirectional semiconductor switching element T2 connected between the connection point between the load 2 and the primary coil 16 and the second individual contact 8 and having a control terminal; Diode D rectifying the output of the coil 17
and a first full-wave rectifier circuit 22 connected between the connection point between the load 2 and the primary coil 16 and the control terminal of the first bidirectional semiconductor switching element T1, and the load 2 and the primary coil 16. a second full-wave rectifier circuit 27 connected between the connection point of the diode D and the control terminal of the second bidirectional semiconductor switching element T2; a capacitor C charged by the output from the diode D; a discharge time constant circuit 30 having a resistor R for discharging the discharge time constant circuit 30; and a control terminal to which the output of the discharge time constant circuit 30 is applied;
7, and when the output of the discharge time constant circuit 30 is equal to or higher than a predetermined value, the semiconductor switching element SCR becomes conductive.
and first and second full-wave rectifier circuits 22, 27
A current flows to the control terminals of the first and second bidirectional semiconductor switching devices T1 and T2 through the first and second bidirectional semiconductor switching devices T1 and T2.
This is a load control circuit characterized in that 1 and T2 are conductive.

The present invention also includes: an AC power source 1; a load 2 connected in series to one output end of the AC power source; a first common contact 6 connected to a terminal of the load 2 on the opposite side of the AC power source 1; The first common contact 6 is selectively switched to conduction by manual operation.
and second individual contacts 7, 8, a second common contact 9 connected to the output end of the AC power supply 1 on the opposite side to the load 2, and this second common contact a second three-way switch having third and fourth individual contacts 10, 11 selectively switched into conduction by manual operation at 9 and connected to the first and second individual contacts 7, 8, respectively; the switch 5; the first primary coil 28 connected between the first and third individual contacts 7 and 10; and the second primary coil 2 connected between the second and fourth individual contacts 8 and 11.
9 and a secondary coil 17 magnetically coupled to these first and second primary coils.
a first bidirectional semiconductor switching element T1 connected between the connection point between the load 2 and the first common contact 6 and between the first primary coil 28 and the third individual contact 10 and having a control terminal; a second bidirectional semiconductor switching element T2 connected between the connection point between the load 2 and the first common contact 6 and the second primary coil 29 and the fourth individual contact 11 and having a control terminal; Diode D rectifying the output of the coil 17
A first full-wave rectifier circuit 22 connected between the connection point between the load 2 and the first common contact 6 and the control terminal of the first bidirectional semiconductor switching element T1, and the load 2 and the first common contact. a second full-wave rectifier circuit 27 connected between the connection point with 6 and the control terminal of the second bidirectional semiconductor switching element T2; a capacitor C charged by the output from the diode D; A discharge time constant circuit 30 having a resistor R for discharging the capacitor C, and a control terminal to which the output of the discharge time constant circuit 30 is applied, the first and second full-wave rectifier circuits 22,
Semiconductor switching element SCR connected to 27
and when the output of the discharge time constant circuit 30 is equal to or higher than a predetermined value, the semiconductor switching element SCR becomes conductive.
and first and second full-wave rectifier circuits 22, 27
A load control circuit characterized in that a current flows through the control terminals of the first and second bidirectional semiconductor switching devices T1 and T2 to cause the first and second bidirectional semiconductor switching devices T1 and T2 to conduct. be.

FIG. 1 is an electrical circuit diagram of an embodiment of the present invention. A lighting lamp 2 such as an incandescent light bulb or a discharge lamp is connected in series to a commercial AC power source 1, and a three-way changeover switch 3, a four-way changeover switch 4, and another three-way changeover switch 5 are connected in series. . The common contact 6 of the three-way changeover switch 3 can be selectively switched to individual contacts 7, 8 by manual operation. In the other three-way changeover switch, the common contact 9 is also connected to the individual contact 10,
11 for conduction. In the four-way changeover switch 4, the individual contacts 12 and 13 are conductive, and at the same time the individual contacts 14 and 15 are conductive.
Furthermore, at the same time that the individual contacts 12 and 15 are electrically connected, the individual contacts 13 and 14 are electrically conductive. The individual contacts 7, 8, 10, 11 of the three-way changeover switches 3, 5 are connected in a corresponding manner to one another via the four-way changeover switch 4 between them. The four-way changeover switch 4 may be omitted, in which case the individual contacts 7, 8 would be connected to the individual contacts 10, 11, respectively. Further, a plurality of four-way changeover switches may be interposed in series between the three-way changeover switches 3 and 5.

A primary coil 16 of a current transformer CT is connected in series to the common contact 6 of the three-way changeover switch 3. The output of the secondary coil 17 of this current transformer CT charges the capacitor C via the diode D. Current transformer
Between the terminal of the primary coil 16 of the CT near the power supply 1 and the individual contacts 7 and 8, there is a triac T as a bidirectional semiconductor switching element having a control terminal.
1 and T2 are connected to each other. Triack T
1 is connected to a full-wave rectifier circuit 22 consisting of diodes 18 to 21. A full-wave rectifier circuit 27 consisting of diodes 23-26 is connected to the other triac T2. Full wave rectifier circuit 2
2 and 27 are connected to a semiconductor switching element SCR having a control terminal. Capacitor C has
A discharge time constant circuit 30 forming a closed loop is connected to the resistor R and the gate of the thyristor SCR via the cathode.

When the three-way changeover switches 3, 5 and the four-way changeover switch 4 are set to the state shown in the first figure, a current flows through the illumination lamp 2, and the illumination lamp 2 is energized and turned on. The output of the secondary coil 17 of the current transformer CT charges the capacitor C by this load current.

Assume that in order to turn off the illumination lamp 2, the common contact 6 of the three-way changeover switch 3 is switched to the individual contact 8 and conductive. This causes the charge in the capacitor C to flow through the resistor R from the gate to the cathode of the thyristor SCR. Therefore, capacitor C is discharged. When the voltage on capacitor C is above a predetermined voltage, thyristor SCR remains conductive, thereby causing diode 19,
A current flows through the thyristor SCR, the diode 21 and the gate of the triac T1, and a current flows from the gate of the triac T1 through the diode 20, the thyristor SCR and the diode 18. In this way, the triac T1 remains conductive for the predetermined time that the thyristor SCR is conductive, i.e. for the period that the voltage on the capacitor C is above a predetermined value. In this way, the common contact 6 of the 3-way changeover switch 3 is changed from the individual contact 7 in the lit state to the individual contact 8 in order to turn off the light.
When the switch is switched to conduction, the load current flows through the triax T1 for a predetermined period of time, and the lighting lamp 2 remains lit. Instead of operating the 3-way selector switch 3, the same operation can be performed by changing the switching mode of the 3-way selector switch 5 and the 4-way selector switch 4.

When the common contact 6 of the 3-way changeover switch 3 is connected to the individual contact 8 to turn on the illumination light 2, the common contact 6 of the 3-way changeover switch 3 is connected to the individual contact 7 to turn off the illumination light 2. When the capacitor C is electrically conductive, the thyristor SCR and therefore the triac T2 remain electrically conductive for a predetermined period of time during subsequent discharge by the discharge time constant circuit 30 of the capacitor C. This operation is performed in the same way even if the other switches 4 and 5 are switched to turn off the light.

FIG. 2 is an electrical circuit diagram of another embodiment of the invention. This embodiment is similar to the first illustrated embodiment described above, and corresponding parts are provided with the same reference numerals.
Note that the current transformer CT has two primary coils 28,29. These primary coils 28,
29 is magnetically coupled to the secondary coil 17. The primary coils 28 and 29 are connected between the individual contacts 7 and 8 of the 3-way switch 3 on one side and the individual contacts 10 and 11 of the 3-way switch 5 on the other hand, that is, between the individual contacts 7 and 8 and the 4-way switch. Individual contact 1 of switch 4
4 and 12, respectively. One end of each of the triaxes T1, T2 is connected to the common contact 6 of the three-way changeover switch 3, and the other end is connected to the individual contacts 14, 12 of the four-way changeover switch 14, 12.
are connected to each.

In this embodiment too, the four-way changeover switch 4 may be omitted, in which case the individual contacts 7, 10 of the three-way changeover switches 3, 5 are connected to the primary coil 28.
are connected to each other via individual contacts 8, 11.
are connected via the primary coil 29. A plurality of four-way changeover switches 4 may be interposed in series between the three-way changeover switches 3 and 5.

In each of the embodiments described above, the illumination light 2 can be turned on and off freely from the locations where the three-way changeover switches 3, 5 and the four-way changeover switch 4 are provided.

As described above, according to the present invention, it is possible to maintain the power energized state of the load for a predetermined period of time after operating the switch for depowering the load.

In particular, in the present invention, since the first and second three-way changeover switches 3 and 5 are provided, on/off control of the load 2 can be performed from each location.

Moreover, the first and second full-wave rectifier circuits 22 and 27
In common, a diode D, a discharge time constant circuit 30,
Since a semiconductor switching circuit SCR or the like is used, the circuit configuration is simplified.

Furthermore, in the present invention, the configurations indicated by reference numerals 32 and 33 in FIGS. 1 and 2, that is, the first three
By replacing the road switching switch 3 and its related parts with the existing 3-way switching switch, it is possible to add a power energization function at a predetermined time after the switch is operated with simple construction work. It becomes like this.

[Brief explanation of the drawing]

Fig. 1 is an electrical circuit diagram of an embodiment of the present invention;
The figure is an electrical circuit diagram of another embodiment of the present invention. 1...Commercial AC power supply, 2...Lighting light, 3, 5...
...3-way changeover switch, 4...4-way changeover switch, 16, 28, 29...Primary coil, 17...
Secondary coil, 22, 27...Full wave rectifier circuit, 30
...Discharge time constant circuit, D...Diode, C...
Capacitor, R...Resistance, CT...Current transformer, SCR
...Thyristor, T1, T2...Triack.

Claims (1)

[Claims] 1. An AC power source 1, a load 2 connected in series to one output end of the AC power source, and a primary coil 16 connected in series to the load 2.
A current transformer CT having a secondary coil 17 magnetically coupled to this primary coil, a first common contact 6 connected to a terminal of the primary coil 16 on the opposite side to the load 2, and this first common contact. 6
a first three-way changeover switch 3 having first and second individual contacts 7, 8 which are selectively switched manually to conduction; and an output end of the AC power supply 1 opposite to the load 2; A second common contact 9 is connected to the second common contact 9, and a third common contact 9 is selectively switched into conduction by manual operation to the second common contact 9 and is connected to the first and second individual contacts 7, 8, respectively. a second three-way changeover switch 5 having fourth individual contacts 10, 11; a second bidirectional semiconductor switching element T2 connected between the connection point between the load 2 and the primary coil 16 and the second individual contact 8 and having a control terminal; Diode D rectifying the output of the coil 17
and a first full-wave rectifier circuit 22 connected between the connection point between the load 2 and the primary coil 16 and the control terminal of the first bidirectional semiconductor switching element T1, and the load 2 and the primary coil 16. a second full-wave rectifier circuit 27 connected between the connection point of the diode D and the control terminal of the second bidirectional semiconductor switching element T2; a capacitor C charged by the output from the diode D; a discharge time constant circuit 30 having a resistor R for discharging the discharge time constant circuit 30; and a control terminal to which the output of the discharge time constant circuit 30 is applied;
7, and when the output of the discharge time constant circuit 30 is equal to or higher than a predetermined value, the semiconductor switching element SCR becomes conductive.
and first and second full-wave rectifier circuits 22, 27
A current flows to the control terminals of the first and second bidirectional semiconductor switching devices T1 and T2 through the first and second bidirectional semiconductor switching devices T1 and T2.
1. A load control circuit characterized in that T2 is conductive. 2 AC power supply 1, a load 2 connected in series to one output terminal of this AC power supply, a first common contact 6 connected to a terminal of the load 2 on the opposite side from the AC power supply 1, and this first common contact 6; A first switch selectively switched to conduction by manual operation to contact 6;
and second individual contacts 7 and 8, a second common contact 9 connected to the output end of the AC power supply 1 on the opposite side to the load 2, and this second common contact. a second three-way switch having third and fourth individual contacts 10, 11 selectively switched into conduction by manual operation at 9 and connected to the first and second individual contacts 7, 8, respectively; the switch 5; the first primary coil 28 connected between the first and third individual contacts 7 and 10; and the second primary coil 2 connected between the second and fourth individual contacts 8 and 11.
9 and a secondary coil 17 magnetically coupled to these first and second primary coils.
a first bidirectional semiconductor switching element T1 connected between the connection point between the load 2 and the first common contact 6 and between the first primary coil 28 and the third individual contact 10 and having a control terminal; a second bidirectional semiconductor switching element T2 connected between the connection point between the load 2 and the first common contact 6 and the second primary coil 29 and the fourth individual contact 11 and having a control terminal; Diode D rectifying the output of the coil 17
and a first full-wave rectifier circuit 22 connected between the connection point between the load 2 and the first common contact 6 and the control terminal of the first bidirectional semiconductor switching element T1, and the load 2 and the first common contact. a second full-wave rectifier circuit 27 connected between the connection point with 6 and the control terminal of the second bidirectional semiconductor switching element T2; a capacitor C charged by the output from the diode D; A discharge time constant circuit 30 having a resistor R for discharging the capacitor C, and a control terminal to which the output of the discharge time constant circuit 30 is applied, the first and second full-wave rectifier circuits 22,
Semiconductor switching element SCR connected to 27
and when the output of the discharge time constant circuit 30 is equal to or higher than a predetermined value, the semiconductor switching element SCR becomes conductive.
and first and second full-wave rectifier circuits 22, 27
A load control circuit characterized in that a current flows through the control terminals of the first and second bidirectional semiconductor switching devices T1 and T2 to cause the first and second bidirectional semiconductor switching devices T1 and T2 to conduct.