JP2012003996A - Lighting fixture for disaster prevention - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guide light lighting device 1 having a good power efficiency by preventing voltage variation of an LED from causing voltage variation of a control circuit 5.SOLUTION: A first rectifying and smoothing circuit 2 rectifies an AC voltage of a commercial power supply and delivers a DC voltage. A first DC/DC converter 3 steps down a DC voltage delivered from the first rectifying and smoothing circuit 2 and delivers the DC voltage to an LED module 4 and a control circuit 5. The first DC/DC converter 3 comprises an output transformer 12, a second rectifying and smoothing circuit 13 and a third rectifying and smoothing circuit 14. The output transformer 12 has a first winding on the input side, and has a second winding and a third winding wound with a reverse polarity for the direction of the second winding on the output side. The second rectifying and smoothing circuit 13 delivers the output voltage from the second winding part to the LED module 4, and the third rectifying and smoothing circuit 14 delivers the output voltage from the third winding part to the control circuit 5.

Description

  The present invention relates to a lighting device for disaster prevention that lights a lighting device for disaster prevention such as a guide light or an emergency light.

Conventionally, a flyback power source is used as a power source for a guide lamp lighting device or the like.
In a conventional flyback power supply, the output voltage (power supply voltage) to the control circuit and the output voltage to the LED are controlled simultaneously.

Patent Document 1 discloses a technique related to a control power supply system for a guide lamp lighting device using an LED as a light source.
The technology disclosed in Patent Document 1 serves as a guide light by turning on a light source (LED) in which no abnormality has occurred even when a short circuit abnormality occurs in the light source (LED) in an emergency such as a power failure or disaster. This is the top priority.

JP 2006-286339 A (see page 1, abstract, FIG. 1)

In a conventional flyback power supply, the output voltage to the control circuit and the output voltage to the LED are controlled simultaneously. Therefore, if the LED voltage changes due to a short circuit failure of the LED or a change in ambient temperature, the voltage of the control circuit also changes. It will change.
For this reason, it is necessary to increase the output voltage to the control circuit in advance in anticipation of a change in the LED voltage, leading to a reduction in power efficiency.

  An object of the present invention is to provide a guide lamp lighting device with high power efficiency without changing the voltage of the control circuit due to the influence of the voltage change of the LED, for example.

The lighting device for disaster prevention according to the present invention includes a rectifying / smoothing circuit that rectifies and smoothes an AC power supply,
A control circuit;
A flyback first DC / DC converter circuit that converts the voltage of the rectifying and smoothing circuit to a low voltage and supplies a constant current to the LED;
A battery used as a power source during a power failure,
A second DC / DC converter circuit for receiving power from the battery output and lighting the LED module;
A third DC / DC converter that boosts the voltage of the battery during a power failure and generates a first control power;
A control power generation circuit for supplying a second control power to the control circuit;
With
The first DC / DC converter circuit has an output transformer,
This output transformer transforms the voltage applied to the first winding connected to the rectifying and smoothing circuit side and the first winding, and the flyback type first connected to the connected LED side. The second winding and the second winding are wound in opposite polarities and have a third winding connected to the control power generation circuit.

  According to the present invention, for example, it is possible to provide a guide light lighting device with high power efficiency without changing the voltage of the lighting control circuit due to the influence of the voltage change of the LED.

1 is a circuit diagram of a guide lamp lighting device 1 according to Embodiment 1. FIG. The circuit diagram of the guide lamp lighting device 1 in Embodiment 2. FIG. FIG. 6 is a circuit diagram of a guide lamp lighting device 1 according to Embodiment 3. The circuit diagram of the guide lamp lighting device 1 in Embodiment 4. FIG. FIG. 6 is a circuit diagram of a guide lamp lighting device 1 according to a fifth embodiment.

Embodiment 1 FIG.
A lighting device that controls lighting of the guide light will be described.
However, you may use the lighting device demonstrated below for lighting control of electric lights other than a guide light.

FIG. 1 is a circuit diagram of a guide lamp lighting device 1 according to the first embodiment.
A guide lamp lighting device 1 according to Embodiment 1 will be described with reference to FIG.
The guide light lighting device 1 constitutes a guide light device together with a guide light panel (not shown) on which marks such as an emergency exit and an escape passage are written.

  The guide light lighting device 1 normally turns on the guide light with power supplied from a commercial power source, and turns on the guide light with power of the battery (battery 6) at the time of a power failure in which the commercial power source cannot be used.

  The guide lamp lighting device 1 includes a first rectifying / smoothing circuit 2, a first DC / DC converter 3, an LED module 4, a control circuit 5, a battery 6, a second DC / DC converter 7, and a third DC / DC. A converter 8 is provided.

  The first rectifying / smoothing circuit 2 receives an AC voltage from a commercial power supply, rectifies and smoothes the input AC voltage, and outputs a DC voltage (pulsating voltage).

  The first DC / DC converter 3 steps down the DC voltage output from the first rectifying and smoothing circuit 2, outputs the stepped down DC voltage to the LED module 4 and the control circuit 5, and outputs a constant current to the LED module 4. It is a constant current circuit to flow through.

The LED module 4 is a light source body in which a plurality of LEDs are connected in series.
The LED module 4 is attached to a light source unit (not shown) of the guide light lighting device 1 together with the guide light panel, and is used as a light source of the guide light device.
However, you may use light source bodies (for example, fluorescent lamp) other than the LED module 4 as a light source of a guide light.

The control circuit 5 is a circuit that controls lighting of the guide lamp lighting device 1.
For example, the control circuit 5 switches to the battery check mode in order to check whether or not the battery (battery 6) can turn on the guide light for a predetermined time (for example, 30 minutes) at the time of a power failure. LED module 4 is turned on.

  The battery 6 is a battery that becomes a power source instead of a commercial power source in the event of a power failure.

  The second DC / DC converter 7 is a constant current circuit that boosts the DC voltage of the battery 6 and outputs it to the LED module 4 instead of the first DC / DC converter 3 in the event of a power failure.

  The third DC / DC converter 8 is a power supply circuit that boosts the DC voltage of the battery 6 and outputs it to the control circuit 5 instead of the first DC / DC converter 3 in the event of a power failure.

  Next, details of the first DC / DC converter 3 will be described.

  The first DC / DC converter 3 includes an output transformer 12, a second rectifying / smoothing circuit 13, a third rectifying / smoothing circuit 14, a resistor 9, a control IC 10, and a switching element 11.

  The output transformer 12 is a transformer that steps down the DC voltage output from the first rectifying and smoothing circuit 2.

The output transformer 12 has a first winding on the input side connected to the first rectifying / smoothing circuit 2, and a second on the output side connected to the second rectifying / smoothing circuit 13 and the third rectifying / smoothing circuit 14. And a third winding.
The second winding is connected to the second rectifying / smoothing circuit 13, and the third winding is connected to the third rectifying / smoothing circuit 14.

The second winding is a winding wound so as to have a polarity opposite to that of the first winding.
The third winding is a winding wound so as to have the same polarity as the first winding and the opposite polarity to the second winding.

  When the switching element 11 is on, current flows through the first winding and the third winding, and when the switching element 11 is off, current flows through the second winding.

In other words, the output transformer 12 constitutes a flyback transformer on the second winding side, and constitutes a transformer having a polarity opposite to that of the flyback (winding in the forward direction) on the third winding side.
However, the second winding side may have a polarity opposite to that of the flyback, and the third winding side may be a flyback method.

  The second rectifying / smoothing circuit 13 includes a diode and a capacitor. The diode is connected in a direction in which a current flows from the positive side of the second winding, and the capacitor is connected in parallel to the second winding.

  The third rectifying / smoothing circuit 14 includes a diode and a capacitor. The diode is connected in a direction in which a current flows from the negative side of the third winding, and the capacitor is connected in parallel to the third winding.

  The resistor 9 is connected in series between the LED module 4 and the second winding of the output transformer 12 and is used to detect the magnitude of the current flowing through the LED module 4.

The control IC 10 is a constant current control circuit that allows a constant current to flow through the LED module 4.
The control IC 10 increases the on-duty ratio (on-time ratio) of the switching element 11 if the current detected by the resistor 9 is smaller than a predetermined value, and the switching element 11 if the detected current is larger than the predetermined value. Reduce the on-duty ratio.

The first embodiment has a feature that the second winding and the third winding of the output transformer 12 output voltages having opposite polarities.
Since the second winding of the output transformer 12 is a flyback system, the energy stored when the switching element 11 is turned on flows as an output current when the switching element 11 is turned off. By smoothing this current and controlling it as a constant current, a voltage is generated in the second winding as a result. On the other hand, since the third winding has a polarity opposite to that of the second winding, the voltage applied to the first winding is transformed and output when the switching element 11 is turned on. At this time, the voltage applied to the first winding is a voltage obtained by rectifying and smoothing the commercial power supply, and has no relation to the voltage of the second winding that is output as a result of being controlled to a constant current. Output depending on the stability of the power supply.

  The waveform of the output voltage to the LED module 4 is upside down with respect to the waveform of the output voltage to the control circuit 5, and when the output voltage to the LED module 4 is positive, the output voltage to the control circuit 5 is zero. When the output voltage to the LED module 4 is zero, the output voltage to the control circuit 5 is positive.

  According to the first embodiment, stable power can be supplied from the third rectifying / smoothing circuit 14 to the control circuit 5 even when the voltage of the LED module 4 changes.

Embodiment 2. FIG.
The form which protects the circuit of the guide lamp lighting device 1 from excessive voltage, such as a surge, is demonstrated based on FIG.
The parts different from the first embodiment will be mainly described, and the description of the same parts as the first embodiment will be omitted.

  The guide lamp lighting device 1 includes a voltage clip circuit 16 that clips (limits or suppresses) an overvoltage such as a surge in addition to the configuration described in the first embodiment (see FIG. 1).

  The voltage clip circuit 16 is a voltage limiter circuit that prevents an overvoltage from being applied to the output-side circuit by conducting when a voltage of a predetermined magnitude or more is applied.

The voltage clip circuit 16 includes a constant voltage diode and a transistor.
The voltage clip circuit 16 is connected to the output of the first rectifying / smoothing circuit 2.

The transistor of the voltage clipping circuit 16 becomes conductive when the output voltage of the first rectifying / smoothing circuit 2 exceeds the breakdown voltage of the constant voltage diode, and a current flows through the voltage clipping circuit 16 to the first DC / DC converter 3. Reduce the output voltage.
The transistor of the voltage clipping circuit 16 does not conduct unless the output voltage of the first rectifying and smoothing circuit 2 exceeds the breakdown voltage of the constant voltage diode.

  As a result, even when an overvoltage such as a surge is applied to the commercial power supply, the circuit of the guide lamp lighting device 1 is protected and applied to the control circuit 5 or the third DC / DC converter 8 to which a voltage proportional to the commercial power supply is applied. Stable power can be supplied.

The voltage clip circuit 16 may be configured according to the overvoltage condition to be suppressed.
For example, the voltage clip circuit 16 may be configured using a varistor.

  Further, the voltage clip circuit 16 may be connected to the input side of the first rectifying / smoothing circuit 2 as long as it can handle AC voltage.

Embodiment 3 FIG.
Another embodiment for protecting the circuit of the guide lamp lighting device 1 from an excessive voltage such as a surge will be described with reference to FIG.
The parts different from the first embodiment will be mainly described, and the description of the same parts as the first embodiment will be omitted.

  In addition to the configuration described in the first embodiment (see FIG. 1), the guide lamp lighting device 1 includes a voltage clip circuit 17 that clips an overvoltage such as a surge at the output of the third rectifying and smoothing circuit 14.

  The voltage clip circuit 17 has the same configuration as that of the voltage clip circuit 16 and operates in the same manner.

  Since a voltage proportional to the commercial power supply is output to the third winding of the first DC / DC converter 3, when an overvoltage such as a surge is applied to the first DC / DC converter 3, Although a surge voltage is generated, the voltage clip circuit 17 can protect the control circuit 5 and the third DC / DC converter 8 and supply stable power.

Usually, since the circuit on the commercial power source side such as the first rectifying / smoothing circuit 2 and the first DC / DC converter 3 is configured to have a withstand voltage of several hundred volts, it is highly resistant to overvoltage.
On the other hand, circuits such as the control circuit 5 and the third DC / DC converter 8 which are circuits on the output side of the first DC / DC converter 3 are not configured to have a resistance of several hundred volts, Weak tolerance.
In this case, if an overvoltage to the control circuit 5 or the like can be prevented, the degree of freedom in selecting the components of the control circuit 5 and the third DC / DC converter 8 is widened, and the components are configured using high-precision and inexpensive components. Can do.

The voltage clip circuit 17 may be configured using another element such as a varistor.
In addition to the voltage clipping circuit 17, a voltage clipping circuit 16 may be provided on the output side or the input side of the first rectifying / smoothing circuit 2 (see FIG. 2).

Embodiment 4 FIG.
Another embodiment for protecting the circuit of the guide lamp lighting device 1 according to the fourth embodiment from an excessive voltage such as a surge will be described with reference to FIG.
The parts different from the first embodiment will be mainly described, and the description of the same parts as the first embodiment will be omitted.

  In addition to the configuration described in the first embodiment (see FIG. 1), the guide lamp lighting device 1 includes a second diode 23 at the output from the third DC / DC converter 8 to the control circuit 5.

The third DC / DC converter 8 includes an inductor 18, a diode 19, a capacitor 22, and a switching element 20, and constitutes a booster circuit.
Further, the third DC / DC converter 8 includes a control IC 21.

The control IC 21 is a constant voltage control circuit that keeps the output voltage of the third DC / DC converter 8 constant.
The control IC 21 detects the output voltage of the third DC / DC converter 8 and controls on / off of the switching element 20 so that the output voltage becomes a predetermined target voltage. In particular, when the output voltage exceeds the target voltage, the operation of the switching element 20 is stopped and the process waits for the output voltage to decrease.

  The second diode 23 is connected to the output portion of the third DC / DC converter 8 in such a direction that current flows from the third DC / DC converter 8 to the control circuit 5, and an overvoltage is applied to the third DC / DC converter 8. Is prevented from being applied.

  Thereby, even when an overvoltage such as a surge is applied to the commercial power supply, the third DC / DC converter 8 can be protected and stable power can be supplied to the control circuit 5.

  Further, a diode may be provided at the output part of the second DC / DC converter 7 to protect the second DC / DC converter 7.

  A voltage clip circuit may be provided as in the second and third embodiments (see FIGS. 2 and 3).

Embodiment 5 FIG.
The relationship between the output voltage of the first DC / DC converter that is the power source of the control circuit 5 during normal operation and the output voltage of the third DC / DC converter 8 that is the power source of the control circuit 5 during a power failure will be described.
The parts different from the first embodiment will be mainly described, and the description of the same parts as the first embodiment will be omitted.

  FIG. 5 is a circuit diagram of the guide lamp lighting device 1 according to the sixth embodiment.

  The configuration of the third DC / DC converter 8 shown in FIG. 5 is the same as that of the fourth embodiment (see FIG. 4).

Hereinafter, the output unit of the third rectifying / smoothing circuit 14 is referred to as a “first control power supply 15”.
The output unit of the third DC / DC converter 8 is referred to as a “second control power supply 24”.
The first control power supply 15 and the second control power supply 24 are connected to the input section of the control circuit 5.

  The first control power supply 15 and the second control power supply 24 are power supplies for the respective control circuits 5, and the first control power supply 15 is used in a normal time when power is supplied from a commercial power supply. Is used during power outages when power is not supplied from commercial power.

By setting the output voltage of the first control power supply 15 higher than the output voltage of the second control power supply 24, the first control power supply 15 is connected to the power supply of the control circuit 5 while power is supplied from the commercial power supply. When the power failure occurs, the second control power supply 24 can be operated as the power supply for the control circuit 5.
When the output voltage of the first control power supply 15 decreases due to a power failure, the voltage of the output section of the second control power supply 24 also decreases, and the control IC 21 that has stopped the operation of the switching element 20 until then causes the second control power supply 24 to stop. This is because the control of the switching element 20 is started so as to keep the voltage of the output section at the target voltage.

The first control power supply 15 is affected by a voltage fluctuation ± 6% of the commercial power supply.
Therefore, when the output voltage of the second control power supply 24 is set to -6% or less of the output voltage of the first control power supply 15 so that the second control power supply 24 does not malfunction due to the voltage fluctuation of the first control power supply 15. Good.
That is, a voltage that is 94% or less of the average output voltage of the first control power supply 15 may be set as the target voltage of the control IC 21.

  Thereby, it is possible to prevent the first control power supply 15 and the second control power supply 24 from operating simultaneously, and to suppress the consumption of the battery 6.

  As in the second to fourth embodiments, a voltage clip circuit or a diode for protecting the guide lamp lighting device 1 may be provided (see FIGS. 2 to 4).

  DESCRIPTION OF SYMBOLS 1 Guide light lighting device, 2 1st rectification smoothing circuit, 1st DC / DC converter, 4 LED module, 5 Control circuit, 6 Battery, 7 2nd DC / DC converter, 8 3rd DC / DC Converter, 9 resistor, 10 control IC, 11 switching element, 12 output transformer, 13 second rectifying and smoothing circuit, 14 third rectifying and smoothing circuit, 15 first control power supply, 16 voltage clip circuit, 17 voltage clip circuit, 18 inductor, 19 diode, 20 switching element, 21 control IC, 22 capacitor, 23 second diode, 24 second control power supply.

Claims (3)

A rectifying / smoothing circuit for rectifying and smoothing the AC power supply;
A control circuit;
A flyback first DC / DC converter circuit that converts the voltage of the rectifying and smoothing circuit to a low voltage and supplies a constant current to the LED;
A battery used as a power source during a power failure,
A second DC / DC converter circuit for receiving power from the battery output and lighting the LED module;
A third DC / DC converter that boosts the voltage of the battery during a power failure and generates a first control power;
A control power generation circuit for supplying a second control power to the control circuit;
With
The first DC / DC converter circuit has an output transformer,
This output transformer transforms the voltage applied to the first winding connected to the rectifying and smoothing circuit side and the first winding, and the flyback type first connected to the connected LED side. A lighting device for disaster prevention, comprising: a second winding, and a third winding wound in the opposite polarity to the second winding and connected to the control power generation circuit.   A guide light comprising the lighting device for disaster prevention according to claim 1.   An emergency light comprising the lighting device for disaster prevention according to claim 1.

Images