JP2012028506A - Led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting device that can completely turn off a light emission diode using a conventional signal control board while a relay of SSR is turned off.SOLUTION: An LED lighting device has an AC power source E and control means SSR for controlling ON/OFF of the AC power source E. The LED lighting device also has a rectifying element D1 for rectifying an AC voltage supplied from the AC power source E to convert the AC voltage to a DC voltage, and a first resistance element R11 and a second resistance element R12 which are connected to each other in series and form a voltage dividing circuit connected to a resistance component Z of the control means through the rectifying element to drop the DC voltage supplied to LED elements D2 to Dn.

Description

  The present invention relates to an LED lighting device, and more particularly to an LED lighting device suitable for use as a pedestrian signal.

  Conventionally, for example, incandescent light bulbs are generally used as lighting elements in pedestrian traffic lights as shown in FIG. On the other hand, in recent years, attention has been paid to light emitting diodes (LEDs) that have low power consumption, long life, easy maintenance, and high reliability. Signal display is achieved by lighting a plurality of such light emitting diodes. A pedestrian signal device that performs the above has been put into practical use.

  As shown in FIG. 4, a conventional pedestrian traffic light includes an AC power source, a semiconductor relay (SSR: Solid State Relay) that switches an AC voltage, and an incandescent bulb.

  On the other hand, as shown in FIG. 5, the pedestrian traffic light using light emitting diodes includes an LED lighting device 16 that displays G and R signals, and a signal switching control unit 14 that performs switching control of the LED lighting device 16. The LED lighting device 16 and the AC power source 12 for the signal switching control unit 14 are configured.

  Here, the signal switching control unit 14 divides the AC current supplied from the AC power source 12 into the control unit 22 side and the LED lighting device side via the breaker 18, and the control unit 22 side has an AC / DC converter 20. Thus, the AC (alternating current) power source is converted into a DC (direct current) power source, and switching control of the SSR 24 is performed by the control unit 22 using the converted direct current power source.

  On the other hand, on the LED lighting device side, SSRs 24a, 24b, and 24c that perform ON / OFF switching operations corresponding to the LED lighting devices of two colors G and R are connected in parallel, and each color is connected to each SSR 24a and 24b. The LED lighting device 16 is connected. The LED lighting device 16 includes an LED group 28a in which a plurality of light emitting diodes are connected in series for each signal color of the rectifying elements 26a, 26b, G, and R as conversion elements corresponding to the SSRs 24a and 24b, 28b, 28c and current control ICs 30a, 30b are connected to each other (see, for example, Patent Document 1).

JP 2000-259993 A

  However, as already explained, the circuit configuration of a conventional pedestrian traffic light and a pedestrian traffic light using a light-emitting diode is greatly different. Therefore, to replace an incandescent light bulb with a light-emitting diode, replace the entire pedestrian traffic light. There was a problem that it was necessary to do so and the cost burden was large.

  Further, when the incandescent light bulb is replaced with a light emitting diode using a conventional traffic light control panel as shown in FIG. 3, the incandescent light bulb does not light even when the traffic light control panel is turned off the SSR relay. There was a problem that a current that would cause light emission would always flow.

  Therefore, the present invention has been made in view of the above-described problems, and provides an LED lighting device that completely turns off a light-emitting diode when an SSR relay is turned off while using a conventional traffic light control panel. With the goal.

  The present invention proposes the following items in order to solve the above problems. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

  (1) The present invention includes an AC power source (for example, equivalent to the AC power source E in FIG. 1) and control means (for example, equivalent to the SSR in FIG. 1) for controlling on / off of the AC power source, A rectifying element (for example, equivalent to the rectifying element D1 in FIG. 1) that rectifies an AC voltage supplied from the AC power source and converts it into a DC voltage, and a resistance component (for example, FIG. 1) through the rectifying element. 1 is connected in series to form a voltage dividing circuit for stepping down a DC voltage supplied to LED elements (e.g., corresponding to LEDs D2 to Dn in FIG. 1). An LED lighting device is proposed that is provided with (for example, equivalent to the resistor R11 in FIG. 1) and a second resistance element (for example, equivalent to the resistor R12 in FIG. 1).

  According to the present invention, when the AC voltage is interrupted, the resistance component of the control means, the first resistance element, and the second resistance element form a voltage dividing circuit, and the DC voltage supplied to the LED element is reduced. Since the voltage is stepped down, the LED element can be reliably turned off even if the control means keeps flowing a current constantly in the off state.

  (2) The present invention relates to the LED lighting device of (1), wherein the first resistor element (for example, equivalent to the resistor R11 in FIG. 1) and the second resistor element (for example, equivalent to the resistor R12 in FIG. 1). And a constant current circuit for supplying a constant current to the LED element (for example, equivalent to the constant current circuit 201 in FIG. 1). And a first switching element (for example, equivalent to the switching element SW2 in FIG. 1) provided between the constant current circuit and the ground, the other end of the voltage detection element serving as the first switching element When the AC voltage is supplied from the AC power source and the output of the rectifying element is equal to or higher than a predetermined voltage value, the voltage detecting element is turned on and the first switching element is turned on. And before Constant current circuit, the LED element (for example, corresponding to LEDD2~Dn in FIG. 1) proposes a LED lighting device and supplying a current to.

  According to this invention, when the other end of the voltage detection element is connected to the first switching element, an AC voltage is supplied from the AC power supply, and the output of the rectifying element becomes equal to or higher than the predetermined voltage value, the voltage detection element Becomes conductive, the first switching element is turned on, and the constant current circuit supplies current to the LED element.

  (3) The present invention proposes an LED lighting device characterized in that, for the LED lighting device of (2), the predetermined voltage value is equal to or less than a rated voltage of the AC power supply.

  According to the example of the present invention, the voltage detecting element detects that the switch of the traffic light control panel is turned on when the voltage supplied from the AC power supply becomes equal to or lower than the rated voltage. Thereby, the LED element can be driven before the voltage supplied from the AC power source reaches the rated voltage.

  (4) The present invention is the LED lighting device according to (1) to (3), wherein a plurality of the LED elements (for example, corresponding to LEDs D2 to Dn in FIG. 1) are connected in series. Has proposed.

  (5) In the LED lighting device according to (1) to (3), the present invention includes a plurality of the LED elements (for example, corresponding to LEDs D2 to Dn in FIG. 1) connected in parallel. Has proposed.

  (6) In the LED lighting device according to any one of (1) to (5), the present invention provides an LED lighting device, wherein the voltage detection element is a Zener diode (for example, the Zener diode ZD1 in FIG. 1). is suggesting.

  According to the present invention, since the voltage detection element is a Zener diode, the voltage can be accurately detected with a simple configuration.

  (7) According to the present invention, in the LED lighting device of (1) to (5), the first switching element (for example, equivalent to the switching element SW2 in FIG. 1) is a MOS-FET. A lighting device is proposed.

  According to this invention, since the first switching element is a MOS-FET, the switch can be configured with a simple configuration.

  (8) In the LED lighting device according to any one of (1) to (5), the present invention is characterized in that the first switching element (for example, equivalent to the switching device SW2 in FIG. 1) is a transistor. Has proposed.

  According to this invention, since the first switching element is a transistor, the switch can be configured with a simple configuration.

  (8) In the LED lighting device according to any one of (1) to (5), the present invention is characterized in that the first switching element (for example, equivalent to the switching device SW2 in FIG. 1) is a thyristor. Has proposed.

  According to the present invention, since the first switching element is a thyristor, the switch can be configured with a simple configuration.

  According to the present invention, there is an effect that the light-emitting diode can be completely turned off while the SSR relay is turned off while using the conventional traffic light control panel. Moreover, since the conventional traffic light control panel is used, there is an effect that the switching cost to the LED lighting device can be greatly reduced as compared with the conventional one.

It is a figure which shows the circuit structure of the LED lighting device of this invention. It is the figure which showed the loss in R1 when switching element SW1 of a traffic light control panel is OFF. It is a figure which shows the external appearance of the conventional pedestrian traffic light. It is a figure which shows the circuit structure of the conventional pedestrian traffic light. It is a figure which shows the circuit structure of the conventional general LED signal apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that the constituent elements in the present embodiment can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. Therefore, the description of the present embodiment does not limit the contents of the invention described in the claims.

<Configuration of LED lighting device>
The configuration of the LED lighting device according to the present invention will be described with reference to FIG. Here, as an example, a pedestrian traffic light will be described as an example, but the present invention is not limited to this.

  As shown in FIG. 1, the LED lighting device according to the present invention includes a control panel 100 and an LED driving unit 200. The control panel 100 is composed of an AC power source E and an SSR. In the present embodiment, the SSR is shown as an electrical equivalent circuit related to the present invention.

  The LED driving unit 200 includes a rectifying element D1, resistors R11 and R12, a switching element SW2, a Zener diode ZD1, LEDs D2 to Dn, and a constant current circuit 201.

  The AC power source E is provided between one end of the SSR and the ground, and the other end of the SSR is connected to the input end of the rectifying element D1. One end of the resistor R11 and the anode of the LED D2 are connected to the output end of the rectifying element D1.

  The other end of the resistor R11 is connected to one end of the resistor R12 and the cathode of the Zener diode ZD1, and the other end of the resistor R12 is connected to the ground. The anode of the Zener diode ZD1 is connected to a control terminal of a switching element SW2 (not shown).

  The LEDs D2 to Dn are connected in series and are provided between the output terminal of the rectifying element D1 and the constant current circuit 201. The constant current circuit 201 is connected to the switching element SW2, and the switching element SW2 is provided between the constant current circuit 201 and the ground.

<Operation of LED lighting device>
The operation of the LED lighting device according to the present invention will be described with reference to FIG.

<Operation when SSR is off>
When the SSR is off, a voltage of about several tens of volts is applied to the voltage dividing circuit formed by the resistor R11 and the resistor 12 connected in series with the resistance component Z of the SSR.

  Here, since the output voltage of the voltage dividing circuit is set lower than the voltage for lighting the LEDs D2 to Dn, the LEDs D2 to Dn are completely turned off when the SSR is off.

<Operation when SSR is on>
When the SSR is on, a voltage obtained by rectifying the AC voltage of the AC power supply E by the rectifying element D1 is converted into a current by the resistor R11, and the Zener diode ZD1 is turned on by this current. Then, when the Zener diode ZD1 becomes conductive, the switching element SW2 is turned on.

  When the switching element SW2 is turned on, the constant current circuit 201 operates and a constant current is supplied to the LEDs D2 to Dn.

  Therefore, according to the present embodiment, the light-emitting diode can be completely turned off while the switching element of the SSR is turned off while using the conventional traffic light control panel. In addition, as shown in FIG. 2, the loss of the resistance forming a part of the voltage dividing circuit is suppressed as low as possible. In addition, since the conventional traffic light control panel is used, the switching cost to the LED lighting device can be greatly reduced as compared with the conventional one.

  The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and includes designs and the like that do not depart from the gist of the present invention.

100; control panel 200; LED drive unit 201; constant current circuit D1; rectifier element D2 to Dn; LED
R11; Resistance R12; Resistance SW1; Switching element SW2; Switching element ZD1; Zener diode

Claims (9)

An AC power supply, and a control means for controlling on / off of the AC power supply,
A rectifying element that rectifies an AC voltage supplied from the AC power source and converts the AC voltage into a DC voltage;
A first resistance element and a second resistance element connected in series to form a voltage dividing circuit connected to the resistance component of the control means via the rectifying element and step down a DC voltage supplied to the LED element;
An LED lighting device comprising: A voltage detection element connected to a connection point between the first resistance element and the second resistance element, a constant current circuit for supplying a constant current to the LED element, and a gap between the constant current circuit and the ground A first switching element provided,
The other end of the voltage detection element is connected to a first switching element, and when the AC voltage is supplied from the AC power supply and the output of the rectifying element becomes equal to or higher than a predetermined voltage value, the voltage detection element becomes conductive. 2. The LED lighting device according to claim 1, wherein the first switching element is turned on and the constant current circuit supplies current to the LED element.   The LED lighting device according to claim 2, wherein the predetermined voltage value is equal to or lower than a rated voltage of the AC power supply.   The LED lighting device according to claim 1, wherein a plurality of the LED elements are connected in series.   The LED lighting device according to claim 1, wherein a plurality of the LED elements are connected in parallel.   The LED lighting device according to claim 1, wherein the voltage detection element is a Zener diode.   6. The LED lighting device according to claim 1, wherein the first switching element is a MOS-FET.   The LED lighting device according to claim 1, wherein the first switching element is a transistor.   The LED lighting device according to claim 1, wherein the first switching element is a thyristor.