JPH0536183Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is an illuminance sensor that detects when the surrounding illuminance has reached a predetermined illuminance, and is equipped with a function that can change the illuminance at which the load is operated. Regarding.

[Prior Art] Illuminance sensors are used to detect ambient illuminance and automatically turn on illuminance devices, for example, when the surroundings become dark. By the way, some of such illuminance sensors are equipped with an illuminance setting volume so that the illuminance at which the illuminance device is turned on can be manually set. However, with this type of conventional illuminance sensor capable of setting the illuminance, there is a problem in that it is difficult to establish a correlation between the volume and the illuminance, and it is difficult to set the illuminance to a desired value.

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and its purpose is to provide an illuminance sensor that can easily set the desired illuminance.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a setting switch that is turned on when the ambient illuminance reaches the desired illuminance when changing the reference value of the comparison section; a reference value variable section that changes the reference value of the comparison section stepwise from a predetermined value from the time of input;
The reference value setting circuit includes a control section that stops the variable operation of the reference value variable section and fixes the reference value when the output of the comparison section is generated.

(Function) The present invention includes a setting switch that is turned on when the surrounding illuminance reaches the desired illuminance when changing the reference value of the comparison section as described above, and a setting switch that is turned on when the setting switch is turned on. A reference value consisting of a reference value variable section that varies the reference value stepwise from a predetermined value, and a control section that stops the variable operation of the reference value variable section and fixes the reference value when the output of the comparison section occurs. By providing a setting circuit, when the ambient illuminance reaches the illuminance at which you want to turn on a light, for example, by turning on the setting switch, the ambient illuminance can be automatically set as the illuminance setting for the illuminance sensor. It is something.

(Example) FIG. 1 shows an example of the present invention. In this embodiment, a lighting device that lights up a sink light when the surrounding illuminance becomes dark and there is a person nearby will be described as an example. In this lighting device, when the illuminance sensor 1 detects that the surrounding illuminance has become darker than the set illuminance, and the human body detection sensor 2 detects the presence of a person, the drive circuit 3 turns on the sink light. It is set to turn on. This drive circuit 3
is a flip-flop FF whose inputs are the output corresponding to the opening/closing of the contact ro, which closes when a person is detected by the human body detection sensor 2, and the output Comp of the illuminance sensor 1.
, a transistor Q ₁ whose conduction is controlled by the output of the flip-flop FF, and a relay Ry ₁ which is driven by the conduction of the transistor Q ₁ and lights up the sink lamp. With this lighting device for the sink light,
Commercial power AC is supplied to each part via a power supply section 5. That is, in this power supply section 5, the voltage of the commercial power supply AC is stepped down by the step-down transformer T, and the voltage that is rectified and smoothed by the diode bridge DB and _the smoothing capacitor _C1 is supplied as a power source for the relay _Ry1 . The voltage rectified and smoothed by the capacitor C ₂ is supplied as a power source for the human body detection sensor 2, and the rectified and smoothed voltage by the rectifier diode D ₁ and the smoothing capacitor C ₂ is further regulated to a constant voltage by the constant voltage circuit 8. It is designed to be supplied as a power source.

The illuminance sensor 1 of this embodiment is composed of a light receiving section 6 that detects the illuminance of the surroundings, and a comparison section 7 that detects when the output LO of the light receiving section 6 reaches an illuminance that turns on the sink light by comparing the output LO of the light receiving section 6 with a reference value REF. The light receiving section 6 uses a phototransistor PT as a light receiving element, and is designed to increase its output as the surroundings become darker. Meanwhile, this embodiment is provided with a reference value setting circuit 4 having the following configuration that changes the reference value REF of the comparison section 7 of the illuminance sensor 1 to turn on the sink light at a desired illuminance. That is, the illuminance sensor is provided with a setting section 16 consisting of a setting switch _SW1 , a capacitor _C3 , and a resistor _R1 that is turned on when the surrounding illuminance reaches a desired illuminance when the reference value REF of the comparison section 7 of the illuminance sensor 1 is changed, a reference value variable section that gradually varies the reference value REF of the comparison section ₇ from the time the setting switch SW1 is turned on, and a control section 4 that stops the variable operation of the reference value variable section and fixes the reference value REF when the output Comp of the comparison section 7 is generated.
The setting unit 16 has setting switches on both ends of the drive power supply.
_SW1 and a capacitor _C3 are connected in series, and the ON state of the setting switch _SW1 is maintained for a period determined by the time constant of the capacitor _C3 and a discharge resistor _R1 connected across the capacitor _C3 .
The set value variable section includes a counter 9 which counts clock pulses CP output from the control section 4 (to be described later).
and a D/A converter 10 for converting the output of the counter 9 into an analog value.
The D flip-flop (hereinafter referred to as D-FF) 12 generates a clock pulse CP for the counter 9 from the clock signal CK output from the clock generating circuit 15 when the power is turned on. The D flip-flop 12 generates a clock pulse CP for the counter 9 from the clock signal CK output from the clock generating circuit 15. The D flip-flop 12 generates a clock pulse CP for the counter 9 from the time when the setting switch _SW1 is turned on (i.e., a reference value
The point when the output LO of the light receiving unit 6 rises above REF)
D _- FF 11 controls D-FF 12 so that the clock pulse CP is output from D-FF ₁₂ until ...
The clock generating circuit 15 is constructed of _C4 to _C6 . The operation of the clock generating circuit 15 is controlled by a transistor _Q2 which becomes conductive when the commercial power supply AC is turned on.

The operation of the reference value setting circuit 4 of this embodiment will be explained below. The illumination intensity in this embodiment is set by turning on the setting switch _SW1 when the ambient illuminance reaches the desired illuminance for turning on the sink lamp. When this setting switch SW ₁ is turned on (this setting switch SW ₁ is a switch that turns on instantly), capacitor C ₃ is charged, and this capacitor
The output of the setting unit 16 is extended until the charged electric weight of _C3 is discharged through the discharge resistor _R1 , and the output of the setting part 16 is extended as shown in FIG.
The signal shown in is output. This signal is further extended by a resistor R ₅ and a capacitor C ₇ as shown in FIG. 2b, and is input to the clear terminal CR of the counter 9. Therefore, the current count value of the counter 9 is cleared, and the outputs _O1 to _O4 all become low level. The output of this counter 9 is the D/A conversion circuit 1
It is inverted at 0 and converted to an analog value, as shown in Figure 2 h.
It is output as a predetermined high voltage as shown in .
In other words, when the output of this D/A conversion circuit 10 becomes the reference voltage REF, the comparison section 7 outputs the output LO of the light receiving section 6.
However, the output Comp (high level) that turns on the sink light will not be generated unless the ambient illuminance is extremely dark (for example, completely dark).
Therefore, in this case, the reference voltage REF of the comparison section 7 is higher than the output LO of the light receiving section 6, which corresponds to the desired illuminance for lighting the sink lamp, so the output of the comparison section 7 is changed as shown in FIG. 2c. Comp becomes Rollbell. Note that before the setting switch SW ₁ is inserted, the output of the NOR circuit 14 of the control section 4 is at a high level, so the inverted output of the D-FF 12 is kept at a low level, and the counter 9 The clock pulse CP is not input to the . Furthermore, when the output of the NOR circuit 14 is at a high level, D-FF1
Since the output ^-1 of the NOR circuit 1 is also at a high level and one input of the NOR circuit 13 is at a high level, the output of the NOR circuit 13 is always kept at a low level regardless of the output Comp of the comparator 7. Here, when the setting switch _SW1 is turned on, the output of the control section 16 becomes high level as shown in FIG. 2b, so that the output of the NOR circuit 14 becomes low level.
When the output of this NOR circuit 14 becomes low level, the output ^-1 of D-FF11 is
As shown in the figure, the clock signal CK output from the clock generation circuit 15 becomes low level at the rising edge (g in the figure). Therefore, since both inputs of the NOR circuit 13 are at a low level, the output is at a high level, and the output of the NOR circuit 14 is at a low level regardless of the input state on the other setting section 16 side. As described above, when the output of the NOR circuit is at a low level, the inverted output Q of the D-FF 12 is at a high level. When the inverted output Q of D-FF12 becomes high level, the resistor _R4 and capacitor
A set signal is input to the set terminal SET of the D-FF 12 at intervals determined by the time constant with _C6 , and the inverted output returns to low level. In this way, each time the clock signal CK is input, the above operation is repeated to generate the clock pulse CP shown in FIG. 2f. The counter 9 performs a counting operation in accordance with this clock pulse CP, and the reference value REF gradually decreases as shown in FIG. 2h. Since the counter 9 in this embodiment has a 4-bit output,
You can change the level in 16 steps. Incidentally, if it is desired to make the level change even finer, the output of count 9 with a larger number of bits may be used. Then, when the output LO of the light receiving section 6 becomes higher than the reference value REF, which is the output of the D/A converting section 10, the output Comp of the comparing section 7 becomes high level. At this time, the output of the NOR circuit 13 becomes high level, and the output of the NOR circuit 14 also becomes high level. Therefore, the clock pulse CP is no longer output from the D-FF 12, the counting operation of the counter 9 is stopped, and the reference value REF is fixed.
In other words, the desired ambient illuminance is the reference value of the comparator 7.
REF, and thereafter, unless the setting switch SW ₁ is turned on again, the illuminance sensor 1 operates at the illuminance according to this reference value REF. In this way, according to this embodiment, when the ambient illuminance reaches the desired illuminance, by turning on the setting switch SW ₁ once, this ambient illuminance becomes the reference value REF for the illuminance sensor 1 thereafter. , the illuminance can be easily changed, and since the reference value REF of the comparing section 7 is set according to the actual surrounding illuminance, there is an advantage that the correlation with the brightness can be well established. By the way, as mentioned above, the NOR circuit 14
When the output of D-FF1 becomes high level,
Since the output ^-1 of 1 also becomes high level, the output of the NOR circuit 13 is kept at low level regardless of the output Comp of the comparator 7 and is not affected by the output Comp of the comparator 7.

[Effects of the invention] As mentioned above, the present invention includes a setting switch that is turned on when the surrounding illuminance reaches the desired illuminance when changing the reference value of the comparison section, and a setting switch that is turned on when the setting switch is turned on to change the reference value of the comparison section. and a control section that stops the variable operation of the reference value variable section and fixes the reference value when the output of the comparison section occurs. Since it is equipped with a reference value setting circuit, for example, when the ambient illuminance reaches the desired illuminance for turning on lights, etc., by turning on the setting switch, the ambient illuminance can be automatically set as the illuminance setting for the illuminance sensor. This has the advantage that the setting is easy, and since the reference value of the comparison section is set according to the actual ambient illuminance, a good correlation with the brightness can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the same operation. 1 is an illuminance sensor, 4 is a reference value setting circuit, 6 is a light receiving section, 7 is a comparison section, 9 is a counter, 10 is a D/A
Converter, 11 is a control section, 16 is a setting section, and SW ₁ is a setting switch.

Claims (1)

[Scope of utility model registration request] In an illuminance sensor equipped with a light receiving section that detects ambient illuminance and a comparison section that compares the output of the light receiving section with a reference value, when changing the reference value of the comparison section, the ambient illuminance becomes the desired illuminance. a setting switch that is turned on when the setting switch is turned on; a reference value variable section that changes the reference value of the comparison section stepwise from a predetermined value from the time the setting switch is turned on; An illuminance sensor comprising a reference value setting circuit comprising a control section that stops variable operation of a variable section and fixes a reference value.