JP2507825Y2 - Lighting equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device, and more particularly to a lighting device which uses an incandescent lamp as a light source and limits an inrush current that may occur when the lamp is lit and an arc discharge current that may occur when the filament is broken. .

[0002]

2. Description of the Related Art The filament resistance of an incandescent light bulb when cold is said to be one tenth or less of that when incandescent. When the rated voltage is applied in such a state, a large current flows into the filament in a short-circuited manner, and the inrush current may shorten the life of the incandescent bulb or damage the power supply device.

The inventor of the present invention uses a device in which an inrush current limiting resistor is connected in series to an incandescent light bulb, and the inrush current limiting resistor is connected to a main circuit of a control rectifying element whose conduction is controlled by a delay circuit. It has been found that the inrush current at power-on can be effectively limited by dividing the power supply voltage to be applied to the incandescent light bulb for a certain period of time after the power is turned on by the inrush current limiting resistor and applying it to the incandescent light bulb. Sho 59-
No. 215697, No. 59-215696,
It is disclosed in Japanese Patent Laid-Open No. 59-230298.

However, it is known that the trigger voltage of the controlled rectifying element fluctuates significantly depending on the junction temperature thereof. For example, when the ambient temperature changes in the range of -40 ° C to + 40 ° C, the trigger voltage is changed. Varies from about 0.9 volts to about 0.6 volts. Therefore, in the conventional device, the operating point of the control rectifying element changes depending on the ambient temperature, and if the ambient temperature is high, the control rectifying element may overheat, shortening its life or even destroying it. It was

Also, for example, Japanese Patent Laid-Open No. 59-230298.
In the case of a device for converting alternating current into direct current and applying it to an incandescent light bulb by a rectifying circuit having a smoothing means, such as the device disclosed in Japanese Patent Publication No. JP-A-2003-264, if the filament is broken during lighting, arc discharge may occur in the breaking gap. is there. With this arc discharge, a large current flows into the electric circuit including the incandescent light bulb almost in a short-circuited manner, which not only causes great damage to the circuit elements such as the rectifying element and the control rectifying element, but is also desirable for safety. I can not say.

[0006]

[Problems to be solved by the invention] In view of such a situation,
The inventor of the present invention can control the rectifying element stably and reliably limit the inrush current even if the ambient temperature changes drastically, and in the unlikely event that the filament breaks during lighting and arc discharge occurs. Even if a problem occurs, we have earnestly studied a lighting device that can quickly extinguish the arc.

[0007]

As a result, the present inventor
Rather than connecting the delay circuit directly to the gate of the main control rectifier connected to the inrush current limiting resistor, an auxiliary control rectifier capable of conducting a current smaller than the main control rectifier between the main control rectifier and the delay circuit. The auxiliary control rectifying element is first made conductive by the delay circuit, and the main control rectifying element is made conductive by utilizing the conduction current, so that the main control rectifying element is overheated even if the ambient temperature changes. Without
It was found that it can be operated reliably.

Further, it has been found that by inserting a resistive element on the AC side of the rectifying circuit, the arc discharge current that may occur when the filament is broken can be effectively limited, and the arc discharge can be extinguished quickly. .

That is, this invention essentially comprises a rectifier circuit including a rectifier and smoothing means, an inrush current limiting resistor connected to the DC side of the rectifier circuit via an incandescent bulb, and the rectifier circuit. A main control rectifying element having a resistive element for limiting an arc discharge current that may occur at the time of filament breakage, and a main circuit connected in parallel to the inrush current limiting resistor, which is inserted on the AC side. It has a connected main electrical circuit to the gate of the controlled rectifier, a possible conduction current smaller than that of the main controlled rectifier, the main electrical circuit
Auxiliary device that can conduct the main control rectifying element by flowing conduction current
Mainly an RC time constant circuit that has a control rectifying element and an output end connected to the gate of the auxiliary control rectifying element, and conducts the auxiliary control rectifying element after a lapse of a certain time from power-on.
The gist of the invention is the structure of the illumination device including the delay circuit.

[0010]

The auxiliary control rectifier operates reliably even if the ambient temperature changes, and the main control rectifier does not overheat due to its conduction current, and the main control rectifier surely conducts.

Even if the filament breaks during lighting and arc discharge occurs, the resistive element effectively limits the large current associated with the arc discharge and quickly extinguishes the arc discharge.

The present invention will be described below with reference to illustrated embodiments.

[0013]

1 is a circuit diagram of the electrical components of an embodiment according to the present invention.

In the figure, AC is an AC power supply, and a power line is usually used. D is a bridge rectifier, the AC side of which is connected to the AC power supply AC via the switch S ₁ and the low resistance R ₁ as a resistive element. Bridge rectifier D
A capacitor C ₁ as a smoothing means is connected in parallel to the DC side of the incandescent lamp L, and an incandescent lamp L is connected to both ends of the capacitor C ₁ via an inrush current limiting resistor R ₂ . The constant voltage diode Z connected in parallel to the AC side of the bridge rectifier D is for preventing an AC overvoltage from being applied to the bridge rectifier D.

The main current path of the main control rectifying element SCR ₂ is connected in parallel to the inrush current limiting resistor R ₂ , and a relatively small current is conducted between its anode and gate through the resistor R _3.
The main circuit of the auxiliary control rectifying element SCR ₁ is connected.
The resistor R ₅ and the capacitor C ₂ are RC time constants having a time constant.
A delay circuit is formed by a circuit, and its output end is connected to the gate of the auxiliary control rectifying element SCR ₁ via a resistor R ₆ .

To explain the operation of this example, when the switch S ₁ is closed, the bridge rectifier D is energized by the AC power supply AC, and its rectified output is supplied to the capacitor C ₁ and smoothed to DC. At this time, the main control rectifying element SCR ₂ is not conducting, so that the DC voltage across the capacitor C ₁ is divided by the inrush current limiting resistor R ₂ and supplied to the incandescent lamp L.

After a lapse of a fixed time determined by the time constant of the delay circuit after the power is turned on, the delay circuit turns on the auxiliary control rectifying element SCR ₁ . Conduction current of the auxiliary controlled rectifier SCR ₁ is applied immediately main control gate of the rectifying device SCR _2, the main controlled rectifier SCR ₂ is conductive. The main controlled rectifier conduction inrush current limiting resistor R ₁ at the same time SCR ₂ is short-circuited, all the DC voltage of the capacitor C ₁ across is to be applied to the incandescent lamp L. After the main control rectifying element SCR ₁ is turned on, the voltage drop across the main controlled rectifying element SCR ₁ is applied to the delay circuit to keep the control rectifying elements SCR ₁ and SCR ₂ conductive.

Since this embodiment is constructed in this way, the resistance value of the inrush current limiting resistor R ₁ is set, for example, so that the current flowing through the incandescent lamp L immediately after the power is turned on becomes approximately its rated current. By setting the time constant of the delay circuit to be long enough to preheat the filament of the incandescent light bulb L, it is possible to make virtually no inrush current into the incandescent light bulb L when the power is turned on. It is possible to prevent the life of the light bulb L from being shortened.

In this embodiment, for example, the auxiliary control rectifying element SCR ₁ has a rated voltage of 0.8 V and a rated current of 0.3.
Milliampere, CR with average drive power of 0.24 milliwatts
02AM is used, and the values of the resistor R ₅ , the capacitor C _2, and the resistor R ₇ are set to 100 kΩ, 220 microfarad and 10 kΩ, respectively, and the time constant of the delay circuit is set to a fraction of a few to several tenths. The gate current of the auxiliary control rectifying element SCR ₁ can be reduced to 1 milliampere or less by setting the time to about 2 seconds. Even if the variation of the gate current due to the temperature change is increased by about 50%, the maximum gate current is 2 milliamperes or less, and it cannot be the electric power that overheats the gate of the main control rectifying element SCR ₂ . The power consumption of the delay circuit at this time is about 0.17 watts (= 130 volts × 130 volts / 100 kilohms), which is extremely small compared to the conventional device.

That is, in the case of the conventional device shown in FIG. 2, even if the auxiliary control rectifying element SCR ₁ is omitted, for example, R ₅ + R
_{If 6 is set} to 3 kOhm and C ₃ is set to 2,000 microfarads, a time constant of about a few seconds is obtained. However, in this case, the operation of the controlled rectifying element becomes unstable in cold regions, so that R ₅ + R ₆ must be set to 2 kΩ or less. Therefore, immediately after turning on the power, a current of 65 milliamperes (= 130 volts / 2 kilohms) is generated.
The current consumption of the time constant circuit is 8.45 watts (= 65 milliamperes × 130 volts), which is about 50 times that of the present invention, and the main control rectifier SCR ₂
There is concern about overheating.

As described above, first, the output of the delay circuit is applied to the auxiliary control rectifying element SCR ₁ which can be driven with a relatively small current to make it conductive, and then the conduction current is used to make the main control rectifying element SCR ₂ By driving the main control rectifier element SCR ₂
Even if the trigger voltage of 1 fluctuates, the conduction of the main control rectifying element SCR ₂ can be stably controlled without overheating. Therefore, even an illumination device designed for cold regions can be stably used under a relatively high ambient temperature.

By the way, in the illuminating device for applying a direct current to the incandescent lamp L to illuminate it as in this example, when the filament of the incandescent bulb L is disconnected during the ignition, arc discharge is generated in the disconnection gap. There is. When an arc discharge occurs, an overcurrent may flow in a short-circuit in the electric circuit including the incandescent light bulb L, and circuit components such as a rectifier and a control rectifying element may be greatly damaged.

In this example, since the low resistance R ₁ is inserted on the alternating current side of the bridge rectifier D, even if the filament is broken during the lighting and arc discharge occurs, a large current accompanying it is generated. It is possible to effectively give a loss and make it difficult to sustain the arc discharge, and prevent damage to the rectifier and the control rectifier element. Should the arc discharge occur again, low resistance R
It will not extinguish at ₁ and will not repeat blinking even after the filament break gap increases, and after the arc discharge extinguishes, the filament is already closed even if the switch S ₁ is closed. Since the wire is broken, the arc discharge will not occur again.

FIG. 3 shows a circuit diagram of electrical components of another embodiment according to the present invention.

In this example, the delay circuit is directly supplied with power from the positive output terminal of the bridge rectifier D for charging.

Similarly to the embodiment shown in FIG. 1, in this example, a low resistance R ₁ is inserted as a resistive element on the AC side of the bridge rectifier D, and the filament is broken while the incandescent lamp L is lit. Even if an arc discharge occurs, a large current is caused to cause a loss and circuit elements such as a rectifier and a control rectifier are prevented from being damaged.

The resistive element used in this invention has another effect of limiting the overcurrent due to the initial charging of the smoothing means. Although the resistance value of the resistive element depends on the voltage value of the AC power supply AC and the rating of the incandescent light bulb L,
With the rectifier circuit inserted on the AC side,
It does not cause a substantial voltage drop so as to prevent unnecessary power consumption.On the other hand, when an arc discharge occurs, a substantial voltage drop may be made to make it difficult to maintain the arc discharge current. Set to 0.5 to 3 ohms.

[0028]

As described above, the lighting device of this invention is
Even if the operating environment changes and the ambient temperature changes and the trigger voltage of the control rectifier changes, the conduction of the control rectifier can be controlled stably, so the rush current to the incandescent bulb does not overheat the control rectifier. Therefore, it is possible to effectively prevent the life of the incandescent light bulb from being shortened due to the inrush current, and to provide light without flicker for a long time. In particular, even if the ambient temperature rises and the trigger voltage of the main control rectifier decreases, the conduction current of the auxiliary control rectifier rises enough to overheat the gate of the main control rectifier. Therefore, there is no need to worry about thermal destruction of the main control rectifier.

Further, in the lighting device of the present invention, since the resistive element is inserted on the alternating current side of the rectifier circuit, the filament may break during lighting and arc discharge may occur in the breaking gap. Also, the circuit elements such as the rectifier and the control rectifying element are not damaged, and it is extremely safe.

Therefore, the lighting device of the present invention is suitable for a lighting device using various incandescent lamps as a light source, and in addition to general lighting, illuminant cultivation of useful plants such as cracked radish, salad vegetables, chrysanthemum, and grapes, and chickens. It can be advantageously used for illuminating and breeding animals such as ayu and ayu, and further for illuminating devices for treating depressed patients.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an electric component of an embodiment according to the present invention.

FIG. 2 is a circuit diagram of an electrical component of a conventional lighting device.

FIG. 3 is a circuit diagram of an electric component of another embodiment according to the present invention.

[Description of sign]

AC AC power supply R _{1 to} R ₇ resistance C _{1 to} C ₃ capacitor Z constant voltage diode S _{1 to} S ₂ switch D bridge rectifier SCR _{1 to} SCR ₂ control rectifier L incandescent light bulb

Claims (1)

(57) [Scope of utility model registration request] 1. A rectifier circuit essentially comprising a rectifier and a smoothing means, an inrush current limiting resistor connected to the DC side of the rectifier circuit via an incandescent lamp, and an AC side of the rectifier circuit. Of the main control rectifying element, which has a main element connected in parallel to the inrush current limiting resistor, and a resistive element for limiting an arc discharge current that may occur when the filament is broken. It has connected the main path to the gate, a possible conduction smaller than the current main controlled rectifier, the main by the conduction current flowing through the main electrical circuit
An auxiliary controlled rectifier capable of conducting a controlled rectifier having an output connected to the gate of the auxiliary controlled rectifier, after elapse of a predetermined time from power, RC time to conduct auxiliary controlled rectifier A lighting device including a delay circuit including a constant circuit .