JPH02148692A - Lighting apparatus - Google Patents

Abstract

PURPOSE:To prevent a circuit element from being damaged without applying a large amount of current to a circuit and improve safety by lighting a lamp bulb at the time of starting the lighting with a current limiting impedance disposed in series to the lamp bulb for checking. CONSTITUTION:A first switching element Q1 is disposed in series to a lamp bulb La. A series circuit A comprising a current limiting impedance R2 and a second switching element Q2 is disposed in parallel to the first switching element Q1. At the time of lighting the lamp bulb La, the second switching element Q2 is turned on prior to the first switching element Q1. The first switching element Q1 is turned on and off with a detected voltage at both ends of the series circuit A or the current limiting impedance R2. At the time of starting lighting of the lamp bulb La, the lamp bulb is lit by first with the current limiting impedance disposed in series to the lamp bulb La. When the lamp bulb used is of a correct rating, the lamp bulb is lit after a delay time through a circuit without using the current limiting impedance to improve safety in lighting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lighting device for lighting a light bulb such as an incandescent emergency light.

[Conventional technology] Conventional equipment that lights light bulbs such as incandescent emergency lights (mini halogen) can be installed in the same socket as the rated lamp even if it is a different type of lamp with different resistance and power consumption than the rated lamp. It is configured so that it can be done.

[Problems to be Solved by the Invention] In conventional light bulb lighting equipment such as incandescent emergency lights as described above, a lamp with a lower lamp resistance and higher power consumption than the rated lamp is mistakenly placed in the same socket in which the rated lamp is installed. If this was installed, there was a problem in that a large current would flow and damage the lighting control switch element.

SUMMARY OF THE INVENTION Therefore, the present invention provides a lighting device that prevents damage to circuit elements even when a light bulb with lower lamp resistance and greater extinguishing power than the rated lamp is attached to the same socket in which the rated lamp is attached. The purpose is to

[Means for Solving the Problem] In order to achieve the above object, the present invention provides: - a sphere [a;
A series circuit A consisting of a first switching element 01 connected in series to the light bulb [a, a current limiting impedance R2 and a second switching element Q2 provided in parallel to the first switching element Q1, a circuit C that turns on a second switching element Q2 prior to the first switching element Q1 when lighting starts; Circuit B that turns off or on (Zener diode 7D, transistor Q3)
The lighting device is constructed by the following.

[Function] When the present invention is applied to an incandescent emergency light, when the regular power supply is normal, the battery is charged and the first switching element Q
1 and the second switching element 02 are turned off, and the light bulb [a, such as an emergency light, is turned off.

When the regular power supply fails and the battery Ba turns on the light bulb [a, the second switching element Q2 is first turned on before the first switching element 01 is turned on.
The light bulb [a is lit in a series circuit with the current limiting impedance R2.

At this time, if the light bulb [a has a small resistance and is larger than the rated value,
Current-limiting impedance R2 and second switching element Q2
Since the detection voltage of the Zener diode 7D that detects both ends of the series circuit is large, the transistor Q3 turns on and the first
The switching element Q1 maintains the off state because the voltage between the gate and the source is low, and the current of the light bulb [a does not become a large current due to the current limiting impedance R2, preventing damage to the circuit elements.

Light bulb 1. When a is a rated light bulb, its resistance is larger than in the above case, and the detection voltage of the Zener diode ZD is small and less than a predetermined value, so the transistor Q3 is turned off, but the first switching element Q1 has a resistance at the start of lighting. It is delayed by the integrating circuit of R3 and the capacitor C1, so it does not turn on immediately, and before that, the second switching element 02
is turned on, the light bulb La is lit through the current limiting impedance R2, and after a delay time by the integrating circuit, the first switching cable Q1 is turned on, and the light bulb La is turned on without passing through the current limiting impedance R2. The light is turned on via the switching element Q1.

As mentioned above, when installing a light bulb in a lighting fixture, when the light bulb starts to light up, the first thing to do is to prevent a large current from flowing through the circuit even if a high power consumption light bulb is mistakenly installed in the same socket as the rated light bulb. The current limiting impedance R2 is inserted in series with the light bulb [a to light it up, and if the installed light bulb is rated, after a delay time, a circuit that does not go through the current limiting impedance is used to light it up.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

S is a regular power supply, T is a transformer, Dl is a diode bridge, and C2 is a capacitor in parallel with this, and normally charges the battery 8a via the diode 02 and resistor I'14.

[a is a light bulb such as an incandescent emergency light that is lit by this battery Ba, and Ql is a first switching element whose source and drain are connected in series to this light bulb [a].

R2 is the current limiting impedance resistor, Q2 is this resistor R2
A series circuit A (within the dotted line frame) of this current limiting impedance R2 and the second switching element Q2 is provided in parallel to the first switching element Q1. 111 is a resistor connected to the gate of this second switching element 02, R3
is a resistor connected to the gate of the first switching element Q1.

lO is the above-mentioned series circuit A or current limiting impedance R2
A Zener diode Q3 that constitutes a voltage detection circuit that detects the voltage across the terminal is a transistor parallel to the capacitor C1 connected to the gate circuit of the first switching element 01, and a Zener diode ZD is connected to the base of the transistor Q3. A circuit B (inside the dotted line frame) is configured by connecting the two to turn off or on the first switching element 01 based on the voltage detected by the voltage detection circuit.

The light bulb [a
A circuit C (inside the dotted line frame) is configured to turn on the second switching element Q2 prior to the first switching element 01 at the start of lighting.

The lighting device of the present invention configured as described above charges the battery 8a when the regular power source is normal, but the gates of the first switching element Q1 and the second switching element Q2 are both connected to the negative side of the diode bridge D1. Both are off because they are connected to the side output terminal and have 0 potential.
Light bulbs such as emergency lights [a are off.

When the regular power supply fails, before the first switching element Q1 turns on, the voltage of the battery Ba is first applied to the gate of the second switching element Q2 via the resistor R1, turning it on, and the light bulb La becomes a current-limiting impedance. A series circuit of R2 and the second switching element 02 is formed and the light is turned on.

At this time, the first switching element 01 is turned off because the potential of the capacitor C1 of its gate circuit has not risen.

In this way, when the light bulb [a] starts lighting, the current limiting impedance R2 is first set before the first switching element Q1 is turned on, so that a large current does not suddenly flow into the circuit.
is inserted in series with the light bulb [a and turned on, thereby turning V
@ Take precautions to prevent damage to the element.

At this time, when the resistance of the light bulb La is small and the power consumption is larger than the rated value, the detection voltage of the Zener diode ZD that detects both ends of the series circuit A of the current limiting impedance R2 and the second switching element 02 is large.

Therefore, transistor Q3 turns on and capacitor C1
Both ends of the switching element Q1 are short-circuited, and the gate of the first switching element Q1 is brought to zero potential to maintain the off state. Therefore, light bulb 1a
is the current limiting impedance R2 and the second switching element Q
The light bulb is turned on through two series circuits, and even if the power consumption of the light bulb La is large, a large current does not flow through the circuit and damage to the circuit elements is prevented. Note that even if a light bulb such as an emergency light is turned on through a current-limiting impedance, it can provide a certain level of brightness, so it is effective for avoiding n-induction.

When the light bulb [a] is a rated light bulb, its resistance is larger than in the above case and the detection voltage of the Zener diode 2D is small, so the transistor 03 is turned off, but the first switching element Q1 is turned off in its gate circuit. It does not turn on until the potential of the capacitor C1 rises, and before that, the second switching element Q2 turns on and the light bulb [a] lights up through the current limiting impedance R2, and when the potential of the capacitor C1 rises, The first switching element 01 is turned on.

As a result, the lighting of the light bulb [a changes from a circuit that goes through the series circuit of the current limiting impedance R2 and the second switching element Q2 to a circuit that lights up the light bulb [a] through the first switching element 01, and continues lighting. Become.

As mentioned above, even if a light bulb with high power consumption is mistakenly installed in the same socket as a rated light bulb, instead of turning on the first switching element 01 immediately when lighting starts, the second switching element Q2 is first turned on before turning on the first switching element 01. By turning on the light and lighting it through the current limiting impedance R2, a large current does not flow through the circuit elements and damage is prevented.

Furthermore, even if the lamp is rated, it is effective in preventing filament damage due to so-called rush current during startup.

Note that the circuit for stopping the first switching element and the method for controlling the connection position and turn-on order of the second switching element are not only configured as described above, but can be modified in various ways. Furthermore, it will be easily understood that the present invention is applicable not only to emergency lights, but also to various lighting devices.

[Effects of the Invention] As mentioned above, the present invention provides that even if a light bulb with a high power consumption is mistakenly attached to the same rated light bulb when installing a light bulb in a lighting equipment, the current limiter is first set when the light bulb starts lighting. Since the impedance is connected in series with the light bulb to light it, a large current does not flow through the circuit and damage to the circuit elements can be avoided.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing one embodiment of the present invention. [a: Light bulb Ql: First switching element Ql: Second switching element R2: Current-limiting impedance A: Series circuit B: Circuit that turns off or turns on the first switching element according to the detected voltage C: First A circuit that turns on a second switching element before the switching element

Claims (1)

[Claims] a series circuit consisting of a light bulb, a first switching element connected in series to the light bulb, a current limiting impedance and a second switching element provided in parallel with the first switching element; A circuit that turns on the second switching element prior to the first switching element, and a circuit that turns off or on the first switching element depending on the voltage across the series circuit or current limiting impedance. A lighting device featuring: