JP2000306683A - Led lighting circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption in standby. SOLUTION: A plurality of light emission diodes(LED) 4, which are adequately interconnected in series responsive to purpose, are connected to an alternating- current power supply 1 through at least a capacitor 2 and a rectifying element 3, and a switch means 5 for opening or closing the LED 4 is an LED lighting circuit controlled by a lighting control means 6. Direct current power supply is supplied to the lighting control means 6 through a second rectifying element 10 for rectifying the alternating-current power supply 1, and when the switch means 5 is opened only the lighting control means 6 substantially consumes power. An output signal of, for example, an illumination sensor 9 is fed into the lighting control means 6, when the circumference has high illumination the switch means 5 is opened to turn off the LED 4, and when the circumference has low illumination the switch means 5 is closed to turn on the LED 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an LED (light emitting diode) lighting circuit.

[0002]

2. Description of the Related Art FIG.
The following is assumed. In this circuit, an AC power supply 1 is connected to an LED 4 via at least a capacitor 2 and a rectifying element 3.
And the switch means 5 for opening and closing the LED 4 is controlled by the lighting control means 6. Then, a constant voltage diode 8 is connected in parallel to the output side of the rectifying element 3 via a resistor 7, and the LED 4 is turned on with a constant voltage output by the constant voltage diode 8. The DC power supplied to the lighting control means 6 uses a constant voltage output from a constant voltage diode 8. For example, the output signal of the illuminance sensor 9 is input to the lighting control unit 6, and the switch unit 5 is opened and the LED 4 is turned off when the surroundings are high illuminance, and the switch unit 5 is closed when the surroundings are low illuminance. The LED 4 is turned on.

[0003]

However, in the above assumed example, even when the switch means 5 is opened and the LED 4 is turned off, the current equivalent to the current flowing through the LED 4 when the LED 4 is turned on is supplied to the constant voltage diode 8 side. LED
It should be noted that there is a problem to be solved that the same power is consumed irrespective of turning on / off of No. 4. The present invention has been made in view of such problems to be solved,
The object of the present invention is to reduce power consumption at the time of turning off light of No. 4, that is, at the time of standby.

[0004]

Means for solving the problems are as described in the claims.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. However, this is merely an exemplary embodiment adopted based on the present invention, and the present invention is described based on matters specific to the embodiment. Therefore, the technical scope of the present invention should be determined based on the matters stated in the claims and matters substantially equivalent to the matters.

In the embodiment shown in FIG. 1, a plurality of LEDs 4 are connected in series to an AC power supply 1 via at least a capacitor 2 and a rectifying element 3 as appropriate according to the purpose. 6. An LED lighting circuit controlled by the DC power supply 6. A DC power supply is supplied to the lighting control means 6 through a second rectifying element 10 for rectifying the AC power supply 1, and substantially when the switch means 5 is open. This is an LED lighting circuit in which only the lighting control means 6 consumes power. Further, for example, an output signal of the illuminance sensor 9 is input to the lighting control unit 6, and the switch unit 5 is opened and the LED 4 is turned off when the surroundings are at high illuminance, and the switch unit 5 is closed when the surroundings are at low illuminance. The LED 4 is turned on.

More specifically, the lighting current of the LED 4 can be adjusted to a predetermined current by selecting the capacitance value of the capacitor 2, and the resistor 11 is connected in series with the capacitor 2 as necessary, so that the lighting current value of the LED 4 can be adjusted. It also contributes to the adjustment and the reduction of the rush current when the AC power supply 1 is turned on. The resistor 12 sets the DC power supply voltage applied to the lighting control means 6 to an appropriate value.

According to the present embodiment, when the switch means 5 is opened, that is, when the LED 4 is turned off, substantially only the lighting control means 6 consumes power, so that the so-called standby power can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an assumed conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 AC power supply 2 Capacitor 3 Rectifier 4 LED 5 Switching means 6 Lighting control means 9 Illuminance sensor 10 Second rectifier

Claims (2)

[Claims] An LED lighting circuit in which an LED is connected to an AC power supply via at least a capacitor and a rectifying element, and switch means for opening and closing the LED is controlled by the lighting control means. An LED lighting circuit in which DC power is supplied via a second rectifying element for rectification, and substantially only the lighting control means consumes power when the switch means is open. 2. An LED according to claim 1, wherein an output signal of an illuminance sensor is input to the lighting control means, and the switch means is opened when the surrounding area is high illuminance, and the switch means is closed when the surrounding area is low illuminance. Lighting circuit.