KR20030031686A - Power supply apparatus for a signal lamp - Google Patents

Abstract

PURPOSE: A power supply unit for signal lamp is provided to supply the stable power to a remaining time indicator by preventing damages of circuits due to counter electromotive force. CONSTITUTION: A power supply unit includes two bridge diodes(BD1,BD2), the first and the second constant-voltage circuits(110,140), a battery(130), and a plurality of diodes(D1,D2,D3). The bridge diodes(BD1,BD2) are used for rectifying the flickering power for flickering a red lamp and a green lamp. An arrester is connected to both input terminals of the bridge diodes(BD1,BD2). A switching mode power supply(100) is connected to both output terminals of the bridge diodes(BD1,BD2) in order to convert AC flickering power to DC power. The first constant-voltage circuit(110) and the diode(D1) are connected to an output terminal of the switching mode power supply(100). The first constant-voltage circuit(110) is used for supplying the output power of the switching mode power supply(100) to the battery(130). The second constant-voltage circuit(110) is used for supplying the output power of the switching mode power supply(100) or the output power of the battery(130) to a remaining time indicator.

Description

Signal light power supply unit {POWER SUPPLY APPARATUS FOR A SIGNAL LAMP}

The present invention relates to a signal lamp power supply, and more particularly, to a signal lamp power supply having a toughness to supply a stable control power.

As income levels rise, households with automobiles are on the rise. As a result of the increase in the supply of automobiles, traffic accidents are also increasing. Looking at the types of traffic accidents, accidents on crosswalks are surprisingly high. Traffic lights installed in crosswalks generally control the crossing of pedestrians by lighting green and red lamps alternately. In such a general traffic light, the flashing green lamp suddenly turns into a red lamp, causing a traffic accident of pedestrians crossing the crosswalk.

In order to solve this problem, it is a traffic light indicating the remaining time. The traffic light indicating the remaining time displays the remaining time from the green lamp to the red lamp, so it is possible to block pedestrians from entering the pedestrian crossing in advance, or to assist pedestrians crossing the pedestrian crossing quickly. Can be.

An example of a circuit configuration of a power supply device used for such a remaining time indicator light is shown in FIG.

Referring to FIG. 1, a green lamp is connected to the P1 terminal, a red lamp is connected to the P3 terminal, and a common terminal such as a signal lamp is connected to the P2 terminal, and voltages of 75 VAC and 9 VAC are output through the first step-down transformer 10. A power supply capable of continuously lighting the light emitting means by discharging the charging voltage when power is not applied to the smoothing capacitor C1 after full-wave rectification through the bridge diodes BD1 and BD2 of the first and second rectifiers 30 and 40. Make

On the other hand, when the red signal is applied, the voltage applied to the P3 terminal outputs a voltage of 9 VAC to the second step-down transformer 20, full-wave rectified by the bridge diode BD3 of the third rectifier 50, and then the smoothing capacitor C4. The voltage is stabilized to connect the + side of the smoothing capacitor of the second rectifying unit 40 at the green signal and the + side of the smoothing capacitor C4 of the third rectifying unit 50 at the red signal to supply power. Connect to the input of the constant voltage IC (RT1) at maximum. At this time, by applying the output of the constant voltage IC to the large-capacity smoothing capacitor (C3) to stabilize as much as possible to use as a control power supply. That is, the voltage stored in the smoothing capacitor C3 is designed to be used when no voltage is applied by the blink signal.

In the power supply having the configuration as described above, the step-down transformer is used to generate the control power of the remaining time indicator and the power for the LED. In the case of using the step-down transformer as described above, circuits connected to the secondary side may malfunction or be damaged by the counter electromotive force due to the coil characteristics during signal switching, and thus, normal control power may not be provided. That is, when the signal is switched from green to red or from red to green, since the counter electromotive force is generated by the coil on the secondary side of the step-down transformer, the smooth capacitor or the bridge diode may be burned out by the counter electromotive force. In addition, in case of sudden power failure, the counter electromotive force voltage can be maximized, so that the circuit elements connected to the step-down transformer secondary side are more likely to be damaged. As such, when circuits connected to the secondary side of the step-down transformer are damaged, the control power cannot be normally supplied and the remaining time cannot be displayed.

Accordingly, an object of the present invention is to provide a power supply device capable of supplying stable operating power to the control unit of the remaining time indicator by excluding the damage of the circuit elements due to the back electromotive force that may occur by using the step-down transformer.

1 is an exemplary configuration of a signal light power supply of the prior art.

2 is a detailed circuit diagram of a traffic light power supply according to an embodiment of the present invention.

Power supply device according to an embodiment of the present invention for achieving the above object;

A plurality of bridge diodes for full-wave rectifying each of the red and green lamp blinking power supplies supplied to flash the green lamp and the red lamp of the traffic light;

A switching mode power supply for converting and outputting an AC flashing power input from a power output terminal of the bridge diodes into a DC power of a predetermined level;

A first constant voltage circuit for inputting the output power of the switching mode power supply to supply a constant voltage form to a battery which is an auxiliary power supply;

And a second constant voltage circuit for supplying a constant voltage to any one of the output power of the switching mode power supply and the output power of the battery to the control power of the remaining time indicator.

According to an additional feature of the invention, further comprises a lightning arrester for discharging the abnormal voltage to the ground across each bridge diode input terminal,

A diode for preventing the inflow of current is further connected to each of the power output terminal of the switching mode power supply and the power output terminal of the first constant voltage circuit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Figure 2 shows a detailed circuit diagram of a traffic light power supply according to an embodiment of the present invention.

Referring to FIG. 2, a signal lamp power supply according to an exemplary embodiment of the present invention includes two bridge diodes BD1 and BD2, two constant voltage circuits 110 and 140, a battery 130, and diodes for preventing current inflow. D1, D2, D3).

The two bridge diodes BD1 and BD2 are full-wave rectified and output each of the red and green lamp flashing power supplies AC RED and AC GREEN supplied to flash the green lamp and the red lamp of the traffic light. Arresters are further connected to both ends of the input terminals of the bridge diodes BD1 and BD2 for discharging an abnormal voltage caused by a lightning strike to the ground.

On the other hand, a switching mode power supply (SMPS) is connected to the output terminals of the bridge diodes BD1 and BD2. The switching mode power supply 100 converts the AC flashing power input from the power output terminals of the bridge diodes BD1 and BD2 into a 12V DC power and outputs the same. In addition, a first constant voltage circuit 110 and a current inflow preventing diode D1 are connected to a power output terminal of the switching mode power supply (SMPS) 100.

As shown in FIG. 2, the first constant voltage circuit 110 includes an amount of current flowing through the current control transistor Q1, the zener diode ZD1 for setting the bias voltage of the current control transistor Q1, and the node ①. And an amplifier 112 and a transistor Q2 for detecting and controlling it. The first constant voltage circuit inputs the output power of the switching mode power supply (SMPS) 100 to supply a constant voltage to the battery BAT 130 which is an auxiliary power supply. In addition, the first constant voltage circuit 110 also includes a diode D2 at the output terminal for preventing current from flowing from the battery 130. A current inflow preventing diode D3 is connected between the battery 130 and the input terminal of the second constant voltage circuit 140 to block inflow of current by the SMPS 100 output voltage. The battery preferably has twice the output of the control voltage. The reason is to supply stable power to the second constant voltage circuit 140.

On the other hand, the second constant voltage circuit 140 serves to supply one of the output power of the switching mode power supply (SMPS) 100 and the output power of the battery 130 to the control power (5V) of the remaining time indicator. Perform. As shown in FIG. 2, the constant voltage circuit 140 includes an LM2578 IC, which is a constant voltage circuit, and a plurality of smoothing capacitors and choke coils L.

Referring to the operation of the power supply having the above-described configuration,

First, when a red lamp blinking power source AC RED is applied to turn on a red lamp of a traffic light, the blinking power source is full-wave rectified through the bridge diode BD1 and applied to the SMPS 100. In addition, the SMPS 100 converts the applied full-wave rectified power into a 12V DC power and outputs the 12V constant voltage to the battery 130 by the first constant voltage circuit 110. Output the constant voltage of 12V down to the control voltage of 5V. Therefore, the controller of the remaining time indicator is supplied with a stable 5V operating power to control the remaining time indicator.

As described above, when the red lamp driving state is switched to the green lamp lighting state, the AC voltage, which is full-wave rectified, is applied to the SMPS 100 by the second bridge diode BD2. The SMPS 100 converts the full-wave rectified AC voltage into a 12V DC power supply and supplies the AC voltage to the first constant voltage circuit 110 and the second constant voltage circuit 140. In this case, since the bridge diode and the SMPS 100 are used instead of the step-down transformer as shown in FIG. 1, the counter electromotive force is not generated by using the step-down transformer. That is, it is possible to always supply a stable 5V control power to the control unit. Even if a power failure occurs, the present invention does not use the step-down transformer, so there is no fear that the circuit elements may be damaged or provide an unstable control voltage by the counter electromotive force generated in the secondary coil.

In conclusion, the present invention generates a DC power by using the SMPS after full-wave rectifying each of the red and green lamp flashing power supplied to flash the green lamp and the red lamp of the traffic light, so that the control unit for controlling the remaining time indicator It is possible to provide a stable control voltage.

As described above, the present invention has the advantage of providing stable operating power to the control unit of the remaining time indicator by excluding the damage of the circuit elements due to the counter electromotive force which may occur due to the use of the step-down transformer. In addition, the present invention also has the advantage that can always supply the operating power to the control unit by using a battery which is an auxiliary power supply.

Claims (3)

Signal light power supply, A plurality of bridge diodes for full-wave rectifying each of the red and green lamp blinking power supplies supplied to flash the green lamp and the red lamp of the traffic light; A switching mode power supply for converting and outputting an AC flashing power input from a power output terminal of the bridge diodes into a DC power of a predetermined level; A first constant voltage circuit for inputting the output power of the switching mode power supply to supply a constant voltage form to a battery which is an auxiliary power supply; And a second constant voltage circuit configured to input one of the output power of the switching mode power supply and the output power of the battery to supply a constant voltage to the control power of the remaining time indicator. The signal lamp power supply apparatus according to claim 1, wherein an arrester for discharging an abnormal voltage to the ground is further connected to each of the bridge diode input terminals. The signal lamp power supply device according to claim 1 or 2, wherein a diode for preventing current inflow is connected to each of the power output terminal of the switching mode power supply, the power output terminal of the first constant voltage circuit, and the power output terminal of the battery.