JPH0319194Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a lighting control device that provides lighting for a certain period of time based on the output of a sensor.

[Conventional technology]

2. Description of the Related Art Conventionally, there is a wall clock in which when you clap your hands at night, a sensor output lights up a lamp for a certain period of time to provide illumination. This is done only at night using CDS,
It supplies power to the sensor and the amplifier for the output of this sensor.

[Problem that the invention attempts to solve]

In the above example, the ambient brightness changes from bright to dark.
Or, there is no problem if the brightness changes instantaneously from dark to bright, but if the brightness gradually changes, the power supply to the sensor and amplifier becomes intermittent, and the operation of the amplifier becomes unstable, causing the output Occasionally, this would cause the lamp to turn on.

The present invention is capable of preventing the illumination device from turning on due to the above malfunction, reducing current consumption, and further preventing unnecessary blinking when the surroundings are dimly lit.

[Means for solving problems]

The present invention is equipped with a prohibition circuit that cuts off power supply to the sensor and output generation circuit when the surroundings are bright, and prohibits lighting of the lighting device when switching the power supply to the sensor and output generation circuit. be.

〔Example〕

In FIG. 1, a lamp 2, which is a lighting device for illuminating a dial and hands, is provided in the upper frame of a wall clock 1, and a window 3 is provided in the lower part.

A concave mirror 4 as shown in FIGS. 2 and 3 is provided within this window 3. An infrared sensor 5 is provided almost at the focal point of the concave mirror 4.
Infrared rays within a certain range of the room are focused by a concave mirror 4 and then focused onto an infrared sensor 5. When the amount of infrared rays changes within the above-mentioned certain range, for example by waving a hand, the lamp 2 is turned on for a certain period of time. However, the detection by the infrared sensor 5 is controlled by a light sensor such as a CDS so that detection is performed only at night, and an example of the circuit configuration will be explained based on FIG. 4.

In the figure, 6 is a CDS, which is provided in a part of the frame of the wall clock 1. 7 is an inverter, 8, 9
is a transistor, and 10 and 11 are resistors. 12
13 is an amplifier that amplifies the output of the infrared sensor 5;
is a comparator, and 14 is a one-shot pulse generator for vibrating the lamp 2. 15 is a one-shot pulse generator consisting of a CR circuit, with a width of approximately 30 mm.
produces a pulse of seconds. 16 is a gate circuit.

In the above configuration, when the surroundings are bright, CDS
The resistance value of the inverter 6 is small, and the output of the inverter 7 is held at 1 due to the divided voltage with the resistor 7, and the transistor 8 is held off. Therefore, power is not supplied to the infrared sensor 5, amplifier 12, camparator 13, and one-shot pulse generators 14 and 15, and they are in an inoperative state.

As the surroundings gradually become dark, the resistance value of the CDS 6 increases and the output of the inverter 7 is reversed to 0, the transistor 8 is turned on and the infrared sensor 5, amplifier 12, comparator 13 and one-shot pulse generator Power is supplied to 15. At this time, since the divided voltage is close to the threshold voltage of the inverter 7, the output of the inverter 7 may swing between 1 and 0.
Therefore, the power turns on and off repeatedly, and the amplifier 12
Also, the output of the comparator 13 may become unstable and a pulse may be generated from the one-shot pulse generator 14.

Therefore, the pulse from the one-shot pulse generator 15 is designed to inhibit the lighting of the lamp 2 due to the pulse from the one-shot pulse generator 14. That is, the one-shot pulse generator 15 is triggered by turning on the transistor 8, and a pulse is generated from its output for about 30 seconds, and the gate circuit 1
The output of 7 is held at 0. Generally, the time when the power supply is unstable is about 20 seconds,
The above-mentioned pulse from the one-shot pulse generator 15 can sufficiently cover the situation, and can prevent the lamp 2 from being erroneously lit.

If you want to know the time late at night, the second
Wave your hand within the condensing range of the concave mirror 4 in FIG. Depending on the setting of this condensing range, the infrared sensor 5 can generate an output by waving a hand while lying down. The output from this infrared sensor 5 is amplified by an amplifier 12, and when this amplified output exceeds a reference level, an output is generated from a comparator 13, a pulse is generated from a one-shot pulse generator 14, and the lamp 2 is lit for a certain period of time. Can read the time.

Even when the surroundings become bright in the morning, the divided voltage between the resistor 10 and the CDS 6 becomes close to the threshold voltage of the inverter 7, and the power supply may repeatedly turn on and off. In this case as well, the lamp 2 is kept in a non-lit state by the output pulse of the one-shot pulse generator 15 in the same manner as described above.

In the above example, an infrared sensor is used as the sensor, but the sensor is not limited to this, and for example, a sensor that is sensitive to a specific sound may be used.

Furthermore, the present invention is not limited to lighting control for watches, but can be applied to anything that uses some kind of sensor to illuminate for a certain period of time only when it is dark.

〔effect〕

According to the present invention, power is supplied to the sensor and output generation circuit only when the surroundings are dark, so it is possible to eliminate unnecessary current consumption by future circuits. Since lighting is prohibited, it is possible to prevent erroneous lighting when the power is repeatedly turned on and off in the evening and at dawn.

[Brief explanation of the drawing]

Figure 1 is a front view showing an example of the use of the present invention in a wall clock, Figure 2 is a plan view showing the main parts of Figure 1 extracted and enlarged, and Figure 3 is the left side of Figure 2. figure,
FIG. 4 is an electric circuit diagram showing an example of the circuit configuration. 2...Lamp, 5...Infrared sensor, 6...
CDS, 7...Inverter, 8...Transistor,
10...Resistor, 12...Amplifier, 13...Comparator, 14, 15...One shot pulse generator, 16...Gate circuit.

Claims (1)

[Scope of utility model registration request] A sensor that is sensitive only to a specific object, an output generation circuit that generates an output for a certain period of time after the sensor is sensitive, a lighting device that lights up based on the output from this output generation circuit, and the surrounding area at a set level. A lighting control device comprising a control circuit that supplies power to both the sensor and the output generation circuit only when it becomes dark, and a prohibition circuit that prohibits the lighting device from turning on when the control circuit switches the power supply. .