JPH089778Y2 - Load control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a load control device, and more particularly, to a main controller using a semiconductor switching element for phase control and a sub-control provided with an operating switch at a location remoter than the main controller. The main controller and the sub controller are connected by two wires, and the control signal is sent to the main controller by operating the operation switch on the sub controller side. The present invention relates to a load control device capable of controlling a load.

BACKGROUND ART In such a load control device, since the number of wires between the main controller and the sub controller is two and remote control can be performed from the side of the sub controller, it is possible to adjust the speed of the light control device and the motor of the lighting. One of the proposed techniques, which is used for the above, has a configuration as shown in FIG. 8, for example. AC power supply AC
And a series circuit of a load (for example, an incandescent lamp) L is connected to the main controller 1 via power lines 1 and 12 while the sub-controller 2 is connected to the main controller 1 via transmission lines l3 and l4. It is connected. The sub-controller 2 is provided with operating switches S1, S2, S3, and when the operating switch S1 is pressed, the power bias from the main controller 1 to the load L is strengthened and the operating switch S2 is pressed. When this is done, the energization of the electric power to the load L is weakened, and when the operating switch S3 is pressed, the electric power is energized or de-energized to the load L. In one such proposed technique, for example, when the operation switch S1 is pressed to intensify the power supply to the load L, when the power supply is turned off, the operation becomes unstable. Therefore, a load control device with stable operation has been desired. Therefore, the inventor of the present application examined a certain proposed technique as described below and made an inference about the cause of unstable operation.

FIG. 5 is an electric circuit diagram showing a basic configuration of a load control device according to a proposed technique, including an AC power supply AC, a load (for example, an incandescent lamp) L, and a main controller (hereinafter referred to as a main unit 1) and a sub-controller (hereinafter referred to as slave unit) 2. The master unit 1 and the slave unit 2 have terminals T3, T5 and terminals T
4, T6 are connected via transmission lines l3, l4, AC power supply A
The series circuit of C and load L is connected to terminal T via power lines 1 and 12
It is connected to base unit 1 via 1, T2. In base unit 1, a phase control switching element (hereinafter referred to as a triac) TA is connected between terminals T1 and T2, and a power circuit of power supply AC and load L is formed via triac TA. TRIAK
The gate G of TA is connected via a line 18 to a control output terminal g of a control circuit 3 realized by a microprocessor or the like.

The terminal T1 of the parent device 1 is further connected to one terminal a of the signal detecting means 4 realized by a photo coupler or the like, and the other terminal b of the signal detecting means 4 is connected to the terminal T3 of the child device 2 via one transmission line l3. Connected to terminal T5. The terminal T4 connected to the terminal T2 in the parent device 1 is connected to the child device 2 via the other transmission line l4.
Connected to terminal T6. The output terminals e1, e2 and e0 of the detection means 4 and the input terminals f1, f2 and f0 of the control circuit 3 are connected to each other by lines l5, l6 and l7, respectively.

In the slave unit 2, one terminals of the operation switches S1, S2, S3 are both connected to the terminal T5, and the other terminal of the operation switch S1 is connected to the anode side of the diode D1 and the other terminal of the operation switch S2 is connected to the other terminal. Each of them is connected to the cathode side of the diode D2. The cathode side of the diode D1 and the diode
The anode side of D2 and the other terminal of operation switch S3 are
Both are connected to the other terminal T6 of the handset 2.

Next, the operation of an electric circuit according to a proposed technique will be described with reference to FIG. When the operation switch S2 is pressed on the slave unit 2 side, the voltage waveform across the triac TA is applied between the terminals T5 and T6 of the slave unit 2 via the detection means 4, and the valve action of the diode D1 causes , The current in the direction indicated by the reference symbol P flows for one half cycle of the voltage waveform across the triac TA while the operating switch S1 is being pressed. The direction of the current at this time (the direction of the reference sign P in FIG. 6) is positive. Next, when the operation switch S2 is pressed, the reference mark q is generated by the valve action of the diode D2.
Current in the direction indicated by flows for the negative half cycle of the voltage waveform across the triac TA. Operation switch
When S3 is pressed, positive and negative currents alternately flow between the master unit 1 and the slave unit 2 while being pressed. As a result, the detecting means 4 determines the operation mode of the operation switches S1 to S3 on the slave unit 2 side as lines (l5, l6) and signals (signals, for example) determined by the direction of the current and its flow time. It is led to the control circuit 3 via l7, and the control circuit 3 performs the judgment and the calculation according to this to calculate the necessary conduction angle for the load L, and the result is triaced from the output terminal g via the line l8. It is applied as a trigger signal to the gate G of TA.
Therefore, the triac A has a period O corresponding to the conduction angle.
The switching operation of N and the non-conduction period OFF is repeated every positive and negative half cycles of the AC power supply AC, and the load control is performed in this manner. For example, if the load L is an incandescent lamp, and the operation switch S1 is displayed as "bright", S2 is displayed as "dark", and S3 is displayed as "point / light", the lamp becomes bright while the operation switch S1 is pressed, and S2 is displayed. Press to darken, and press S3 to turn off the light when it is on and turn it on when it is off.

However, in one such proposed technique, for example, the operation switch S1 is pressed to turn off the light even though the user desires to make the illumination brighter, or the operation switch S2 is pressed to reverse. An unstable operation condition, such as bright and dull conditions, often occurs, and thus a load control device with stable operation has been desired.

The inventor of the present invention has (1) the waveforms at both ends of the triac as to the cause of the above-mentioned unstable operation.
(2) It was inferred that it was due to stray capacitance (strike capacitance) existing in the transmission line between the master and slave.

FIG. 6 is a diagram showing waveforms at various parts of the circuit according to a proposed technique. In each figure, the vertical axis represents voltage level and the horizontal axis represents time. The corresponding phase angle is also shown on the time axis by the arc method (π = 180 °). The waveforms of FIG. 6 will be described below with reference to FIG.

FIG. 6 (1) shows a voltage waveform of the AC power supply AC. Sixth
FIG. 2B shows a voltage waveform across the triac TA when the conduction angle = θ. When the phase of the triac TA is controlled by the conduction angle θ, the triac TA is in the ON state during the period from time t1 to t2, t3 to t4, t6 to t7, ...
The voltage waveform of the hatched area in Figure (2) is the load L.
, And the waveforms during the remaining time t0 to t1, t2 to t3, t4 to t6, ... Are the voltage waveforms across the triac TA. FIG. 6 (3) shows the voltage waveform applied to the load L at this time, and FIG. 6 (4) shows the voltage waveform across the triac TA at this time. As described above, the voltage waveform of FIG. 6 (4) is derived to the slave unit 2 side as a signal waveform. When the operation switch S1 is pressed on the slave unit 2 side, the detecting element of the detecting means 4 (for example, a photocoupler, not shown, corresponding to the positive half cycle period of the signal waveform of FIG. 6 (4). 6), a current flows as shown in FIG. 6 (5), which causes the detection means 4 to generate an alternating waveform of levels "0" and "H" as shown in FIG. 6 (6). It is led out between the output terminals e1 and e0 and applied to the input terminal of the control circuit 3. FIG. 6 (7) shows the waveform between the other output terminals e2 and e0 of the detection means 4 at this time, and the level thereof is constant. Therefore, the control circuit 3 determines the waveform shown in FIG. 6 (6) as an input and outputs a trigger necessary for the triac TA. The waveforms of FIGS. 6 (8) and (9) will be described later.

In this way, the voltage waveform across the triac TA,
Therefore, the signal waveform given to the cordless handset 2 is the time determined by the conduction angle θ, as shown in Fig. 6 (4).
Since it is cut off at t1, t3, t6, ..., A surge voltage containing a large amount of harmonic components is generated. Moreover, the level of this surge voltage becomes maximum when the conduction angle θ is 90 °, and is generated in both positive and negative cycles of the waveform.

FIG. 7 is an electric circuit diagram showing a proposed technique. FIG. 7 has the same configuration as that of FIG. 6, and the corresponding parts are designated by the same reference numerals. In FIG. 7, the detecting means 4 is a photocoupler P1 of the first detecting element and a photocoupler of the second detecting element.
Each of the photocouplers P1 and P2 is composed of P2, and each is composed of light emitting diodes LD1 and LD2 which are light emitting elements and phototransistors Q1 and Q2 which are light receiving elements. AC power source AC is the place of commercial power source, one end of which is normally grounded. Stray capacitances (strike characteristics) SC1, SC2 and SC3 are inevitably present between the transmission lines l3 and l4 and between the ground and the respective transmission lines l3 and l4.
It increases as 3, l4 becomes longer distance. Therefore, if the operation switch S1 is pressed on the slave unit 2 side, only the current in the direction indicated by the reference symbol P flows in the detecting means 4,
Therefore, only the light emitting diode LD1 of the photocoupler P1 of the first detection element emits light, and the waveform shown in FIG. 6 (6) should be derived as the output only between the terminals e1 and e0. As described above, since a surge voltage is generated even within the negative half cycle period, this surge voltage waveform has a reference mark h, j or a reference mark m through the stray capacitances SC1, SC2, etc.
The stray currents of the direction indicated by are generated, and these currents are in the opposite direction to the current of the direction indicated by the reference symbol P in the negative half cycle period, whereby the light emitting diode LD2 of the second detection element P2 is As shown in FIG. 7 (8), light is emitted for a period of Δθ, and therefore the detecting means 4 derives the output waveform shown in FIG. 7 (9). Therefore, even though only the operation switch S1 is pressed on the slave unit 2 side, the switching mode is the same as if S1 and S2 were pressed at the same time. That is, in this case, the detection means 4 is operated by the operation switch.
Since it is considered that S3 is pressed, the result is contrary to the state desired by the user. The above is the inference made by the inventor of the present invention regarding a problem of a proposed technique.

Based on the above reasoning, in order to eliminate the influence of the stray current, the inventor of the present invention connects the surge voltage absorbing capacitor C1 and the stray current bypass capacitor C2 to the locations indicated by the dotted lines in FIG. 7, respectively. Although the above-mentioned operation instability was eliminated and the desired effect was achieved, the capacitors C1 and C2 in this case must have a high withstand voltage that is commensurate with the power supply voltage of the AC power supply AC. Since the voltage waveform contains a large amount of harmonic components, it was necessary to select a capacitor with good frequency characteristics. Therefore, the external shape of the capacitor becomes large and the cost becomes high.

Therefore, the object of the present invention is to solve the above-mentioned technical problems and to provide a load control device which is stable in operation and can be manufactured at low cost.

Configuration of the Invention In the present invention, (a) a load L, a semiconductor switching element TA for phase control, and an AC power supply AC are connected in series to form a closed loop. (B) At both ends of the semiconductor switching element TA, A pair of Zener diodes in which one ends of the first and second resistors r1 and r2 are respectively connected, and between the other ends of the first and second resistors r1 and r2, which are connected in series or in parallel with mutually opposite polarities.
Z1 and Z2 are connected, and (c) the first transmission line 13 is connected to the other end of the first resistor r1 through the first and second light emitting diodes LD1 and LD2 that are connected in parallel in mutually opposite polarities. (D) The second transmission line l4 is connected to the other end of the second resistor r2, and (e) the first diode D1 and the first operation are connected between the first and second transmission lines l3 and l4. A first series circuit composed of a switch S1, a second series circuit composed of a second diode D2 having a polarity opposite to that of the first diode D1 and a second operation switch S2, and a third operation switch S3 are connected in parallel. (F) The light from the first and second light emitting diodes LD1 and LD2 is received by the respective light receiving elements Q1 and Q2, and (g) the semiconductor switching is performed in response to the output of each light receiving element Q1 and Q2. By controlling the element TA, the power of the load L is increased by receiving light from only one light receiving element Q1 and receiving only the other light receiving element Q2. A load control device is provided which is provided with a control circuit 3 for weakening the power energization of the load L by light and energizing or deenergizing the power of the load L by the light reception of both light receiving elements Q1, Q2. Is.

Embodiment FIG. 1 is an electric circuit diagram of an embodiment of the present invention. First
The circuits shown in the figures have the same reference numerals in the corresponding parts in the circuits of FIGS. 5 and 6. It should be noted that resistors r1 and r2 and Zener diode Z1 are connected across the triac TA.
The voltage dividing means 5 by Z2 is connected in parallel with the triac TA, and the level of the divided voltage is such that the conduction angle Θ of the triac TA of the first light emitting diode LD1 and the second light emitting diode LD2 constituting the detection element 4 is maximum. It is set to a level that allows stable light emission even when Therefore, even when the conduction angle Θ is 90 °, the level of the above-mentioned signal waveform does not exceed the level set by the voltage dividing means 5 and is suppressed to a certain level or less and the surge waveform is absorbed. That is, the signal waveform is subjected to the waveform shaping action by the zener diodes Z1 and Z2, and the signal waveform becomes a low level waveform of a square wave to a waveform close to a square wave. The capacitor C1 connected in parallel with the zener diodes Z1 and Z2 is a filter for removing the harmonic components generated by the signal waveform thus obtained being a square wave. According to the experiment conducted by the inventor of the present invention, the operation of the device itself was not affected even if omitted.

FIG. 2 is a diagram showing the waveform of each part in the electric circuit of FIG. FIG. 2 (1) shows the voltage waveform across the triac TA when the conduction angle = Θ. FIG. 2 (2) shows a signal waveform which is shaped by the zener diodes Z1 and Z2 and converted to a low level. Figure 2 (3) shows the condenser
It is shown that the addition of C1 removes the harmonic components contained in the square wave and blunts the waveform, resulting in a trapezoidal wave. FIG. 2 (4) is a photocoupler which is the first detection element of the detection means 4 when the operation switch S1 is pressed on the side of the slave unit 2.
The output waveform of P1 is shown. Fig. 2 (5) shows the second
The output waveform of the photocoupler P2 which is a detection element is shown. As a result of the signal waveform being lowered in level as described above, the surge waveform as described above is not affected even during the negative switching period t3 to t4, t7 to t8, ... Of the triac TA, and its level is constant. Is shown.

Referring again to FIG. 1, the detection means 4 outputs the output corresponding to the switching mode of the operation switches S1 to S3 on the slave unit 2 side to the control circuit 3 via the lines l5, l6 and l7, and the control circuit 3 By this, the judgment / calculation is performed, and a trigger signal corresponding to the required conduction angle is applied to the gate G of the triac TA through the line l8, whereby the power energization to the load L is controlled. Although the Zener diodes Z1 and Z2 are shown as being connected in anti-series in the above-described embodiments, the configurations shown in FIGS. 3 (1) and 3 (2) can also be implemented.

FIG. 5 is an electric circuit diagram of the stabilized power supply PS for driving the control circuit 3 described above. Input terminal u of stabilized power supply PS,
v is connected to the terminals T1 and T2, and the voltage waveform across the triac TA (not shown) is applied. TRIAK
The conduction angle Θ controlled by TA is set so that Θ <π even when it is set to the maximum, in other words, even if the maximum energization time is set for the load L, Δ (for example, 30 °). ) Is set so that the non-energized period remains. Therefore, the stabilized power supply PS is still energized by the power corresponding to the above Δ even when the load power reaches the maximum. The above power applied to the stabilized power supply PS is the capacitor C
2, applied to diode bridge DB via resistor r3, full-wave rectified, smoothed by capacitor C3 and added to the collector of transistor Q3, while on the other hand, by a constant voltage circuit by resistor r4, zener diode Z3. Then, the output voltage VC, VS appearing at the collector of the transistor Q3 is divided and applied to the base of the transistor Q3, and is applied to the control circuit 3 while being constant regardless of the fluctuation of the input voltage. To drive. In this embodiment, the transistor Q3 and the zener diode Z3 are used as the constituent requirements of the stabilized power supply circuit PS, but a voltage stabilizing element such as a three-terminal regulator may be used instead of them.

Effect According to the present invention, a semiconductor switching element for phase control
One end of each of the first and second resistors r1 and r2 is connected to each end of the TA, and the other ends of the first and second resistors r1 and r2 are connected in series or in parallel with opposite polarities. By connecting the pair of Zener diodes Z1 and Z2 connected to each other, the voltage between the first and second transmission lines l3 and l4 can be always maintained at a constant value. As a result, when the first to third operation switches S1 to S3 are operated, the first and second light emitting diodes LD1 and LD2 can be surely made to emit light, and the control can be surely performed. Can be prevented. In addition, the voltage between the first and second transmission lines l3, l4 is lowered,
It is possible to prevent the generation of noise. This makes it possible to stabilize the operation.

Since the current flowing between the first and second transmission lines l3 and l4 may be weak, the lines l3 and l4 can be made thin, which also has the effect of facilitating the wiring work.

Further, according to the present invention, three operation switches S1 to S3 are connected to the first and second transmission lines l3 and l4,
The power of the load is strengthened, weakened, or urged / de-energized, and the above-described control of the load L can be performed by a simple wiring work, and the effect that the configuration is simple is achieved. It

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an embodiment of the present invention, and FIG.
FIG. 1 is a waveform diagram of each part of the electric circuit shown in FIG. 1, FIG. 3 is a diagram showing how to connect the zener diodes Z1 and Z2, and FIG. 4 is an electric circuit diagram of a stabilized power supply PS in one embodiment of the present invention. Fig. 6 is an electric circuit diagram showing a certain proposed technique, Fig. 6 is a diagram showing waveforms of each part of the electric circuit shown in Fig. 5, and Fig. 7 is a reasoning of the present inventor for a certain proposed technique. FIG. 8 is a diagram showing the configuration of a certain proposed technique. DESCRIPTION OF SYMBOLS 1 ... Main controller, 2 ... Sub controller, 3 ... Control circuit, 4 ... Detecting means, 5 ... Voltage dividing means, P1, P2 ... Photo coupler, TA ... Phase control switching element, S1-S3 ... Operation switch, PS … Stable power supply, L… Load, AC… AC power supply, 1, l2… Power line, l3, l4… Transmission line

Claims (1)

[Scope of utility model registration request] 1. A closed loop is formed by (a) connecting a load L, a semiconductor switching element TA for phase control, and an AC power supply AC in series, and (b) a first loop at both ends of the semiconductor switching element TA. And a pair of Zener diodes Z connected to one ends of the second resistors r1 and r2, respectively, and connected in series or in parallel to each other between the other ends of the first and second resistors r1 and r2.
(C) The first transmission line 13 is connected to the other end of the first resistor r1 via the first and second light emitting diodes LD1 and LD2 connected in parallel with each other in opposite polarities. (D) The second transmission line l4 is connected to the other end of the second resistor r2, and (e) the first diode D1 and the first operation are connected between the first and second transmission lines l3 and l4. First consisting of switch S1
A series circuit, and a second diode D2 and a second diode D2 having a polarity opposite to that of the first diode D1.
The second series circuit including the operation switch S2 and the third operation switch S3 are connected in parallel, and (f) the light from the first and second light emitting diodes LD1 and LD2 is supplied to the light receiving elements Q1 and Q2. Accordingly, (g) the semiconductor switching element TA is controlled in response to the outputs of the respective light receiving elements Q1 and Q2, and the power of the load L is strengthened by receiving light from only one light receiving element Q1. The control circuit 3 is provided to weaken the power energization of the load L by receiving only the light receiving element Q2, and to energize or deactivate the power to the load L by receiving the light of both the light receiving elements Q1 and Q2. Characteristic load control device.