JPS648918B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light control device capable of controlling the light of a light source such as an incandescent light bulb in stages by operating a pull switch, for example.

2. Description of the Related Art As a device for continuously controlling the light of a light source for illumination, there is a variable power control device disclosed, for example, in Japanese Patent Application Laid-Open No. 82864/1983.

This device uses two touch switches to control the charging and discharging of a capacitor through a neon discharge tube, and also controls the charging time constant of a relaxation oscillator circuit containing an N-gate silicon controlled rectifier to an insulated gate field effect transistor and its input terminal. The thyristor is controlled by the connected capacitor, and the output of the oscillation circuit is directly applied to the bidirectional thyristor to control the phase of the load.

Therefore, first, the dimming is controlled by using two touch switches, etc., which is cumbersome to operate. Next, there is a drawback that fluctuations in the terminal voltage of the capacitor provided at the input end of the insulated gate field effect transistor directly affect load power as fluctuations. Although the capacitor is a field effect transistor, the terminal voltage of the capacitor gradually decreases over time, which has an undesirable effect on the load.
Furthermore, since there is a residual charge in the capacitor when the power is turned on, there is a drawback that the lighting state when the power is turned on is not constant.

This invention eliminates the above-mentioned drawbacks and changes the number of clock pulses depending on the operating time of the operating switch,
By cyclically counting clock pulses using a shift register, selecting a resistor according to the count, and generating a gate signal according to that resistor to dim the light, the operation switch can be easily operated and the light source can be dimmed. The object is to provide a dimming device that can perform accurate and stable dimming.

An embodiment of the present invention will be described below with reference to the drawings.

As shown in Figure 1, the main circuit of this dimming device connects one end of the AC power source Es to one end of a light source L such as a lamp via a phase control device such as a triax _Q1 , and connects the other end to the light source L. by connecting it to the other end of the

A full-wave rectifier D ₀ consisting of four diodes is connected between both terminals of the AC power supply Es, and a constant voltage diode ZD ₁ and a capacitor C ₁ of the polarity shown are connected in parallel between the output terminals of the rectifier D 0 through a resistor R ₁ . The circuits are connected to configure a first rectified constant voltage power supply.

Similarly, a constant voltage diode ZD ₂ and a capacitor C ₂ are connected across the output terminals of the full-wave rectifier D ₀ through a resistor R ₂
A second rectified constant voltage power supply is constructed by connecting the parallel circuits of the two.

Next, to explain the clock pulse generation circuit in the ignition phase control circuit, this circuit is a constant voltage diode.
Connect a series circuit of resistor R ₃ and resistor R ₄ between the terminals of ZD ₁ , and connect resistor R ₅ and capacitor C ₃ via pull switch SW as an operating switch.
Connect a series circuit of resistor R ₅ and capacitor C ₃
to the anode of PUT Q ₂ , said resistor R ₃
and R ₄ are connected to the gate of PUT Q ₂ , and the cathode thereof is grounded via resistor R ₆ .

Next, the clear pulse generation circuit is a constant voltage diode.
A series circuit of capacitor C ₄ and resistor R ₇ is connected between the terminals of ZD ₂ .

Further, as the shift register IC, for example, a static shift register whose internal circuit is composed of a D-type flip-flop and an inverter and which reads data at the rising edge of a shift pulse applied to a clock terminal can be used.

In the shift register IC shown in Figure 1, 1 is a power supply V _DD terminal, 2 is a data input terminal, 3 is a clear input terminal, 4 is a clock terminal, and 5 to 8 are
Q ₁ ′ to Q ₄ ′ output power terminals, and 9 indicates a ground terminal.

A plurality of resistors R 8 to R ₁₁ having different resistances and having one end connected to each of the output terminals Q ₁ ′ to _{Q 4} ′ of the shift register ₁₆ are provided. The resistors R ₈ to R ₁₁ are used to set the firing phase in stages, and their respective resistance values are selected so that the range of change in illuminance for each stage is visible.

Next, I will explain the gate signal generation circuit.
The other ends of the resistors R ₈ to _{R 11} are connected together and connected to the signal input end of this gate signal generation circuit. That is,
The resistors R ₁₂ to R ₁₇ , the transistor Q ₃ , the PUT Q ₄ , the capacitor C ₅ and the transformer TR constitute a gate signal generation circuit consisting of a PUT relaxation oscillation circuit. More specifically, a constant voltage diode
The connection point of resistors R ₁₂ and R ₁₃ connected between the terminals of ZD ₂ is used as the input terminal of the gate signal generation circuit, and this connection point is further connected to the base of transistor Q ₃ via resistor R ₁₄ . The collector of Q ₃ is a constant voltage diode through a resistor R ₁₅
Connect to the positive terminal of ZD ₂ , emitter is capacitor C ₅
Ground through.

On the other hand, a resistor is placed between the terminals of the constant voltage diode ZD ₂ .
Connect the series circuit of R ₁₆ and R ₁₇ , connect the connection point to the gate of PUT Q ₄ , which is the ignition element, connect the emitter of the transistor Q ₃ to the anode of PUT Q 4, and connect its cathode to the gate of PUT Q ₄ , which is the ignition element. Ground through the primary side. In addition, transformer TR 2
The configuration is such that a gate signal is supplied to triac _Q1 from the next side.

Next, the operation of this light control device will be explained. First, when the power source Es is turned on with the pull switch SW serving as the operation switch open, a charging current flows through the capacitor _C4 in the clear pulse generation circuit, and a pulse voltage is generated across the resistor _R7 . This voltage serves as a clear pulse to the shift register IC.
is applied to clear input terminal 3 of . In this state, although the power supply voltage V _DD and data input are applied to the shift register IC, the shift pulse is not applied to the clock terminal 4, so the output terminal 5
-8, no output voltage is generated. Therefore, the base of transistor _Q3 is a constant voltage diode.
The voltage given by ZD ₂ is applied to resistors R ₁₂ and R ₁₃
A relatively low base bias voltage is set by dividing the voltage by and applying it through the resistor _R14 . Therefore, the trigger phase of the triax _Q1 is also relatively delayed, and the voltage supplied to the light source L is also a relatively low value.

Next, when the contact of the pull switch SW is closed, while the contact is closed, the clock pulse generation circuit consisting of resistors _R3 to _R6 , PUT _Q2 , and capacitor _C3 operates, and evenly spaced pulse voltage is applied to resistor _R6 . Occurs on both ends. This voltage is supplied as a clock pulse to the clock input terminal 4 of the shift register IC.
As a result, first, at time t ₁ , the shift register IC
Q ₁ ′ output is generated, and this output continues to be generated because the data input is continuously applied as DC.

In response to this, the base of the transistor Q ₃ in the relaxation oscillator circuit has a voltage regulated by the constant voltage diode ZD ₂ divided by the parallel resistance values of the resistors R ₈ and R ₁₂ and the resistor R ₁₃ . A value approximately equal to the value will be applied. In other words, the bias between the times t ₀ and t ₁ described above
The base bias of Q ₃ increases, which advances the trigger phase of the triax Q ₁ and also increases the voltage applied to the light source L.

When time advances further and reaches _t2 , the clock pulse generation circuit consisting of PUT _Q2 etc. generates a second pulse across the resistor _R6 , and this is supplied to the clock input terminal 4 of the resistor IC, so the above-mentioned Similarly, the Q ₂ ' output terminal 6 of the shift register IC also generates an output voltage. This results in transistor Q ₃
At the base of , there is a parallel resistance value of resistors R ₈ , R ₉ and R ₁₂ with a voltage specified by the constant voltage diode ZD ₂ and a value approximately equal to the voltage divided by the resistor R ₁₃ . is applied through resistor _R14 .

As a result, the base bias of transistor _Q3 increases further than the bias between times _t1 and _t2 ,
Therefore, the trigger phase of the triax _Q1 also advances further, and the voltage applied to the light source L also increases further.

After that, when time t ₃ is reached through the same process, Q ₃ ′ output of the shift register is generated, and when time t ₄ is reached, Q 3 ′ output is generated.
The Q ₄ ' output is generated and the base bias of the transistor Q ₃ increases accordingly, so that the voltage applied to the light source L increases stepwise.

In this state, even if the contact of the pull switch SW is kept closed after time _t4 , a clock pulse will still be generated, but in this case, there will be no output from the shift register IC in response to it, so it will not affect the voltage applied to the load. Moreover, no matter when the contact of the pull switch SW is opened, this switch SW is in a separate system from the power supply that supplies the power supply voltage V _DD and data input of the shift register IC, so in the case of Fig. 1, the AC power supply Es
As long as the shift register IC is connected, the output of the shift register IC that was occurring until then will continue to be generated.
Therefore, the voltage applied to the light source L also remains at a constant level without changing its value.

In this way, five output levels including the first level can be obtained by opening and closing the contacts of the pull switch SW. The number of output levels can be easily increased by increasing the number of output terminals of the shift register IC.

In this lighting equipment, the level of the voltage supplied to the light source can be arbitrarily set by opening and closing one contact in the signal circuit. Therefore, even if this unit is installed on a high ceiling, the illuminance can be changed to increase in stages as shown in Figure 2 depending on how long the pull switch SW is pulled. If you let go of the light, you can maintain the illuminance that was just before it.

Furthermore, the time required for the change is constant for each stage, and the width of change E _A of the illuminance for each stage is adjusted to a visible level by setting the resistors R ₈ to R ₁₁ , for example. If the width of this change is small, it becomes difficult to distinguish between each stage due to the visual afterglow effect, and if it is too large, the desired brightness cannot be obtained because the number of changes from the dark state to the bright state is small.

Therefore, it is desirable to set the range of change as follows. That is, if the illumination intensity at the maximum output is 100, and the illumination intensity is 5 to 10, and the illumination intensity at time t1 in FIG. ₂ is 40 to 60, then about 6 levels can be obtained. Moreover, the time required to move to one stage is
Make it about 0.3 to 0.8 seconds. In this way, the illuminance changes by 5 to 10% for one stage transition, so there is little afterglow effect, the user can clearly feel the illuminance change, and the increments are small enough for practical use. It can be made into something.

Therefore, the user can easily and accurately adjust the illuminance by closing the pull switch SW and watching the illuminance change step by step, and then opening the switch SW when the desired brightness is reached.

In particular, this light control device changes the number of clock pulses according to the operation time of the operation switch, counts the clock pulses cyclically using a shift register, selects a resistor according to the count, and outputs a gate signal according to the resistor. (1) There is a single operation switch, and the desired degree of dimming can be easily set by simply controlling the on/off of the switch.

(2) Since the shift register reliably maintains the output as long as there is no input pulse, the dimming level will not undesirably fluctuate depending on the lighting time.

(3) As the clear pulse generation circuit operates and clears the shift register at the same time as the power is turned on, a constant dimming level can be set at all times when the power is turned on.

It has the following features.

In this dimming device, the shift register operates cyclically as described above, so even if you want to adjust the dimming level once you have set it again, you only need to operate a single operation switch in the same way as you did the first time. Light level can be set.

In the case of the conventional technology, one switch only increases the load conductivity, and the other switch only decreases it, so it is necessary to use them separately, which makes operation cumbersome, but in the case of the present invention, For example, if the dimming level is configured to change from low to high, if the operation switch is operated continuously, the dimming level will change from low to high.
Since it changes from large to large, the operation can be stopped when the desired level is reached.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without changing the gist.

For example, in the above embodiment, the illuminance increases step by step, but the present invention can also be configured so that the illuminance gradually decreases over time as shown in FIG.

In addition, as the operating switch, we have explained the case of a pull switch as shown in Figure 4a.
The present invention is not necessarily limited to this, and a toggle switch or rotary switch as shown in FIGS. b and c may be selected as appropriate.

As described above, according to the present invention, the number of clock pulses is changed according to the operating time of the operating switch, the clock pulses are counted cyclically by a shift register, a resistor is selected according to the count, and a gate is set according to the resistor. By generating a signal and controlling the light, it is possible to provide a light control device that allows easy operation of the operation switch and accurately and stably performs light control of the light source.

[Brief explanation of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention, FIGS. 2 and 3 are stepwise illuminance change characteristics diagrams for explaining the operation of the present invention, and FIG. 4 is a diagram of various types of illuminance used in the present invention. It is an explanatory view showing an example of an operation switch. Es...AC power supply, Q ₁ ...Triack, L...
...Light source, D ₀ ... Full-wave rectifier, R ₁ to R ₁₇ ... Resistor,
C ₁ to C ₅ ... Capacitor, DZ ₁ , DZ ₂ ... Constant voltage diode, Q ₁ , Q ₄ ... PUT, Q ₃ ... Transistor.

Claims (1)

[Claims] 1. A phase control device that controls the phase of alternating current; a light source that dims and lights according to the output of this phase control device;
A rectified constant voltage power supply, a clock pulse generation circuit whose input terminal is connected to this power supply, an operation switch that controls the operation of the clock pulse generation circuit, and a clock pulse input terminal that inputs clock pulses and outputs one of multiple output terminals depending on the number of clock pulses. a shift register that generates an output, and a clear pulse generation circuit whose input end is connected to the rectified stable power supply and whose output end is connected to a clear terminal of the shift register, and which generates a clear pulse when the power is turned on to clear the shift register; A plurality of resistors having different resistance values each having one end connected to each output end of the shift register, and a resistor having the other end connected to the signal input end and selected by the operation of the shift register. A dimming device comprising: a gate signal generating circuit that generates a gate signal whose phase is controlled according to a resistance value, and controls the conduction phase of the phase control device using the gate signal. Device.