JPH06335235A - High-frequency lighting device for halogen incandescent electric lamp - Google Patents

Abstract

PURPOSE:To reduce the brightness of a halogen incandescent electric lamp when its life approaches its end to protect a switching element and at the same time show that its life is near the end by monitoring the temperature increase of the switching element of a high-frequency conversion means and then limiting the output of a rectifier circuit based on the temperature. CONSTITUTION:When the life of a halogen incandescent electric lamp 30 approaches its end, lamp current increases, a temperature fuse provided at both or either of the cooling fins of transistors 10 and 11 of a high-frequency inverter 40 operates, and a contact 15 is turned off. Then, a commercial AC power supply 1 is half-wave-rectified by a diode 16 connected in parallel with the contact 15 and is input to a rectifier circuit 4 and is smoothed by a smoothing capacitor 5 and then supplied to the high-frequency inverter 40, thus reducing the brightness of the halogen incandescent electric lamp 30, showing the end of its life, and preventing the switching elements 10 and 11 of the high-frequency inverter 40 from being damaged due to an excessive current at the end of the life.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency lighting device for a halogen light bulb for converting a commercial power supply into a high frequency to light a halogen light bulb, and more particularly to control of a rectifying circuit at the end of the life of the halogen light bulb.

[0002]

2. Description of the Related Art In recent years, there has been a demand for downsizing of lighting fixtures, with an emphasis on the landscape of buildings, and in order to meet such demands, compact and highly efficient low-voltage compact halogen bulbs are widely used. Has become. The rated voltage of this type of halogen bulb is, for example, 12 V, and it is not possible to directly connect it to a commercial power source for lighting, so a step-down means is required. As a step-down means for commercial power supply, a step-down transformer compatible with commercial power supply frequency is conceivable, but the one that directly rectifies and smoothes the output of the step-down transformer is relatively large and heavy, and downsizing the lighting equipment.・ The requirement for weight reduction cannot be satisfied. In order to solve such a problem, it has been proposed to light a halogen bulb with high frequency power. In addition, the first feature of the luminaire having such a small light source is that the luminaire itself can be made small,
Providing a separate emergency lighting fixture or a fixture with a different shape contradicts the idea of emphasizing the landscape of a building.

Therefore, in order to provide a high-frequency lighting device for halogen light bulbs with a high-frequency lighting device for halogen light bulbs, a storage battery and a power supply device for emergency lighting are provided in addition to the high-frequency lighting device for halogen light bulbs by lighting the halogen light bulb by direct current power supplied from a separate power source. There was a demand for something that could be used as an emergency lighting fixture without special work (for example, installing these on the ceiling).

FIG. 3 is a circuit diagram showing the structure of a conventional high-frequency lighting device for a halogen bulb, for example. In the figure, 1 is a commercial AC power supply, 2 is an emergency DC power supply, 3 is a switch for switching between a commercial AC power supply and an emergency power supply, 4 is a rectifier circuit including a diode bridge for rectifying the commercial AC power supply 3, and 5 is a rectifier circuit. It is a capacitor that charges the output of No. 4 and has a small capacitance. A series circuit of a resistor 6 and a capacitor 7, a series circuit of a capacitor 8 and a capacitor 9 and a series circuit of a transistor 10 and a transistor 11 are connected to both ends of the capacitor 5, and the transistors 10 and 11 are respectively connected in parallel with a regenerative current bypass. Diodes 12 and 13 are connected. A trigger element composed of a bidirectional conducting element is connected between the connection point between the resistor 6 and the capacitor 7 and the base of the transistor 11.

Reference numeral 15 is a contact of a thermal fuse provided on either or both of the heat radiation fins provided on the transistors 10 and 11, and the commercial AC power supply 1 and the rectifier circuit 4 are provided.
Has been inserted between and. In 20, one end of the primary winding is connected to the connection point between the capacitor 8 and the capacitor 9, both ends of the secondary winding are connected to the base and emitter of the transistor 10, and both ends of the other secondary winding are connected to the transistor. 11 is a current transformer connected to the base and emitter, 22 is 1
One end of the secondary winding is connected to the connection point between the transistor 10 and the transistor 11, and the other end of the primary winding is the current transformer 2
0 is a step-down transformer connected to the other end of the primary winding,
The current transformer 20 is a saturated type and the step-down transformer 22 is an unsaturated type. Further, the resistor 6, the capacitors 7, 8 and 9, the transistors 10 and 11, the diodes 12 and 13, the trigger element 14, the current transformer 20 and the step-down transformer 22 constitute a self-excited half-bridge high-frequency inverter 40. Reference numeral 30 is a halogen bulb connected to the secondary winding of the step-down transformer 22.

Next, the operation of the conventional example will be described. Figure 4
FIG. 4 is a diagram showing waveforms of an input voltage of a rectifier circuit 4 of a conventional example and a lamp current flowing through a halogen bulb. When the power source is turned on, the commercial AC power source 1 is rectified by the rectifier circuit 4, and the rectified power source charges the capacitor 7 through the capacitors 5, 8, 9 and the resistor 6. When the voltage across the capacitor 7 reaches the breakover voltage of the trigger element 14 (for example, about 8V), the trigger element 14 is turned on and the transistor 11 is turned on. After that, the trigger element 14 is repeatedly turned on and off by the voltage of the capacitor 7, but this does not affect the switching of the transistor 11 as described later.

When the transistor 11 is turned on, the primary winding of the current transformer 20, the primary winding of the step-down transformer 22,
The electric charge of the capacitor 9 is discharged through the transistor 11. That is, the lamp current flows through the halogen bulb 30 connected to the secondary winding of the step-down transformer 22.

Further, when the transistor 11 is turned on from off, a voltage is induced in the secondary winding of the current transformer 20 in a direction in which the transistor 10 is reverse biased and the transistor 11 is forward biased. When the saturation or the change in the current flowing through the primary winding of the current transformer 20 decreases, the voltage induced in the secondary winding becomes zero, and the transistor 11 turns off. At this time, since the current flowing through the primary winding of the current transformer 20 rapidly decreases, the transistor 1 is connected to the secondary winding of the current transformer 20.
A voltage is induced in a direction in which 0 is forward biased and transistor 11 is reverse biased. And transistor 1
1 is completely off and transistor 10 is on.

When the transistor 10 is turned on, the electric charge of the capacitor 8 is discharged through the transistor 10, the primary winding of the step-down transformer 22 and the primary winding of the current transformer 20. That is, a lamp current reverse to that when the transistor 11 is turned on flows through the halogen bulb 30 connected to the secondary winding of the step-down transformer 22.

When the transistor 10 is turned on from off, a voltage is induced in the secondary winding of the current transformer 20 in such a direction that the transistor 10 is forward biased and the transistor 11 is reverse biased. When saturated or when the change in the current flowing through the primary winding of the current transformer 20 decreases, the voltage induced in the secondary winding becomes zero and the transistor 10 turns off. At this time, since the current flowing through the primary winding of the current transformer 20 rapidly decreases, the transistor 1 is connected to the secondary winding of the current transformer 20.
A voltage is induced in such a direction that 0 is reverse biased and transistor 11 is forward biased. And transistor 1
0 is completely off and transistor 11 is on.

By repeating this operation, the high frequency inverter 40 supplies high frequency power to the halogen bulb 30. At this time, when the transistors 10 and 11 are repeatedly turned on and off, the trigger element 14 is also turned on and off by the voltage of the capacitor 7, but when the trigger element 14 is turned on, the secondary of the current transformer 20 on the transistor 11 side. When a voltage that forward-biases the transistor 11 is generated in the winding, most of the base current is the current from the secondary winding of the current transformer 20, so there is no effect on the switching of the transistor 11, and When a voltage that reverse-biases the transistor 11 is generated in the secondary winding of the current transformer 20 on the transistor 11 side, switching of the transistor 11 is performed by setting the voltage to be larger than the voltage of the capacitor 7. Will not be affected.

While the high frequency inverter 40 is operating, the voltage of the capacitor 5 is small because the electrostatic capacity of the capacitor 5 is small.
0V at a voltage almost along the envelope of the output voltage of the rectifier circuit 4.
The voltage will not be Therefore, a high-frequency voltage obtained by dividing the voltage of the capacitor 5 by the capacitors 8 and 9 is applied to the primary winding of the step-down transformer, and the lamp current when the halogen bulb 30 is normal is shown in FIG. It becomes a waveform.

During the oscillating operation, the step-down transformer 22 is set to 1
Since the output voltage of the rectifier circuit 4 is divided by the capacitors 8 and 9 and a half of the output voltage of the rectifier circuit 4 is applied to both ends of the next winding, the step-down transformer 22 uses the commercial AC power supply 100V. Can be made smaller than when directly stepping down, and because the step-down transformer is used at high frequencies, it is even smaller.

By the way, it is known that when the halogen bulb 30 reaches the end of its life, the filament of the bulb becomes thin, and an electric current larger than the normal lamp current flows. When the halogen bulb 30 reaches the end of its life, a large amount of lamp current tends to flow, so that an excessive current flows in the secondary winding of the step-down transformer 22. When an excessive current flows in the secondary winding of the step-down transformer 22, the primary winding of the current transformer 22, the transistor 1
A current larger than the normal current also flows through the capacitors 0, 11 and the capacitors 8, 9. Overcurrent is transistor 1
If it continues to flow at 0 and 11, it may generate heat and eventually be damaged.

Therefore, in the conventional circuit, the transistor 10 or the transistor 11 or the transistor 10,
When both the heat dissipating fins 11 are provided with temperature fuses and the halogen current 30 reaches the end of its life, the lamp current increases and the transistors 10 and 11 generate heat, the contact 15 is turned off by the operation of the temperature fuses. As shown in (b) of item (b), measures are taken to prevent breakage of the transistors 10 and 11 by cutting off the AC power supply and stopping the power supply to the high frequency inverter 40.

[0016]

In the conventional high-frequency lighting device for a halogen bulb as described above, the halogen current 30 reaches the end of its life, the lamp current increases, and the transistor 10,
When 11 heats up, the contact 1 is generated by the operation of the thermal fuse.
Since the power supply to the high-frequency inverter 40 is stopped by turning off 5, the halogen bulb 30 is temporarily extinguished at the end of its life, the temperature fuse is restored, and its contact 15 is turned on. Since the halogen bulb 30 is turned on again at times, there is a problem that the halogen bulb 30 repeatedly blinks to cause discomfort. Further, when there is a power failure in an emergency and the halogen bulb 30 has to be turned on for emergency lighting, if the halogen bulb 30 is normal, the rectifier circuit 4 is provided with an emergency DC power source as shown in FIG. 4C. The voltage of 2 is input and the lamp current flows. But,
When the temperature fuse is not restored and the contact 15 is in the off state, the emergency DC power supply 2 is not supplied as shown in (d) of FIG. There was a problem of disappearing.

The object of the present invention is to solve the above problems by limiting the electric current to the halogen bulb at the end of its life to bring the halogen bulb into a dimmed state.
It is an object of the present invention to provide a high-frequency lighting device for a halogen bulb, which is capable of protecting the switching element and notifying that the halogen bulb is at the end of its life. Further, in addition to the above objects, another object of the present invention is to be able to supply an emergency DC power supply even during a power failure used as an emergency lighting fixture even when the halogen bulb is at the end of its life. It is to provide a high-frequency lighting device for a halogen light bulb that can fulfill the above-mentioned function.

[0018]

According to a first aspect of the present invention, there is provided a high frequency lighting device for a halogen light bulb, comprising a rectifying circuit for rectifying AC of a commercial AC power source, a capacitor for charging an output of the rectifying circuit, and at least one switching element. And a high-frequency conversion means for converting the DC voltage across the capacitor into a high-frequency voltage for lighting the halogen bulb and the temperature of at least one switching element of the high-frequency conversion means, and based on the temperature, the output of the rectifier circuit It is provided with control means for limiting.

A high-frequency lighting device for a halogen bulb according to a second aspect of the present invention has a rectifier circuit for full-wave rectifying the alternating current of a commercial AC power source, a capacitor for charging the output of the rectifier circuit, and a capacitor having at least one switching element. Is provided in at least one switching element of the high-frequency conversion means for converting the DC voltage across both ends into a high-frequency voltage to turn on the halogen bulb, and its contact is inserted at the input side of the rectifier circuit to reduce the temperature of the switching element. It is provided with a temperature fuse that monitors and turns off the contact when a certain set temperature is reached, and a diode connected in parallel to the contact of the temperature fuse.

A high-frequency lighting device for halogen bulbs according to a third aspect of the present invention is the high-frequency lighting device according to the first or second aspect of the present invention, which comprises an emergency DC power source connected in parallel to a commercial AC power source via a changeover switch. Power is supplied from the emergency DC power supply when the AC power supply fails.

[0021]

In the first aspect of the invention, the rectifier circuit rectifies the alternating current of the commercial AC power source, the capacitor charges the output of the rectifier circuit, and the high frequency conversion means having at least one switching element converts the DC charge of the capacitor to a high frequency. The converted halogen bulb is turned on, the temperature of at least one switching element of the high-frequency conversion means is monitored by the control means, and the output of the rectifying circuit is limited based on the temperature.

In the second invention, the alternating current of the commercial alternating current power source is rectified by the rectifier circuit, the output of the rectifier circuit is charged by the capacitor, and the DC charge of the capacitor is converted to a high frequency by the high frequency conversion means having at least one switching element. When the halogen bulb is converted, the temperature of the switching element is monitored by a temperature fuse provided in at least one switching element of the high-frequency conversion means and the contact of which is inserted in the input side of the rectifier circuit, and when a certain set temperature is reached, The contact is turned off, and the commercial AC power supply is half-wave rectified by the diode connected in parallel with the contact.
In the third aspect of the invention, when the commercial AC power supply fails, power is supplied to the high frequency conversion means by the emergency DC power supply connected in parallel to the commercial AC power supply via the changeover switch.

[0023]

1 is a circuit diagram showing the configuration of a high-frequency lighting device for a halogen bulb according to an embodiment of the present invention. In the figure, the same components as those of the conventional example are designated by the same reference numerals, and the description of the duplicate components is omitted. Reference numeral 16 is a diode connected in parallel to the contact 15 of the thermal fuse, and the contact 15 and the diode 16 constitute a control means.

Next, the operation of this embodiment will be described. FIG. 2 is a diagram showing waveforms of the input voltage of the rectifier circuit 4 and the lamp current of the halogen light bulb 30 of the embodiment. First,
The halogen bulb 30 is normal and the transistors 10, 1
When the thermal fuses provided in both or either of the heat radiation fins provided in 1 do not operate and the contact 15 is on, the operation is the same as in the conventional example, and as shown in FIG. The waveform is as shown. When the halogen bulb 30 reaches the end of its life, the lamp current increases in the transistors 10 and 11. Then, the thermal fuses provided in both or either of the heat radiation fins provided in the transistors 10 and 11 operate, and the contact 15 thereof is turned off.

When the contact 15 is turned off, the commercial AC power supply 1 is half-wave rectified by the diode 16 connected in parallel to the contact 15 and input to the rectifier circuit 4, and the output of the rectifier circuit 4 is half the commercial AC power supply 1. Wave rectified, smoothed by the smoothing capacitor 5, and the high frequency inverter 4
Supplied to zero. Therefore, the voltage and the lamp current input to the rectifier circuit 4 have the waveforms shown in FIG.
The electric power supplied to the high-frequency inverter 40 is halved, and the halogen bulb 30 continues to light in a dimmed state.

In case of a power failure in an emergency, the power source of the high-frequency lighting device for a halogen bulb is switched from the commercial AC power source 1 to the emergency DC power source 2 (DC1) by the changeover switch 3.
00V), and DC power is supplied from the input terminal of the halogen bulb high-frequency lighting device in the same manner as when commercial AC power is supplied.

Therefore, since a direct current voltage is applied to the input terminal of the high-frequency lighting device for a halogen bulb, the diode 16 prevents the contact 15 of the temperature fuse from being turned on or off, as shown in (c) and (d) of FIG. As shown, a predetermined DC power is supplied to the high frequency inverter 40, and the halogen light bulb 30 can be emergency-lit. In this case, if the halogen bulb 30 is at the end of its life and the transistors 10 and 11 are provided with radiation fins that are not damaged in a limited emergency lighting time even when the lamp current is increasing more than usual, the emergency lighting fixture is provided. It is possible to fulfill the function as.

In this embodiment, the diode connected in parallel to the contact 15 of the temperature fuse inserted in the input side of the rectifier circuit 4 connects the AC of the commercial AC power supply 1 to a half wave when the halogen bulb is at the end of its life. Although rectification is performed, the temperatures of the transistors 10 and 11 can be monitored and the rectification circuit 4 can be controlled to change from a full-wave rectification circuit to a half-wave rectification circuit at the end of the life of the halogen bulb. Further, in this embodiment, the high frequency inverter 40 is a self-excited half-bridge type high frequency inverter having two transistors, but it may be another type of high frequency inverter.

[0029]

As described above, according to the present invention, when the halogen bulb reaches the end of its life, the current flowing through the halogen bulb increases, an excessive current flows through the switching element of the high frequency conversion means, and the temperature of the switching element rises. Since the power input to the high frequency conversion means is reduced,
When the halogen bulb is at the end of its life, the halogen bulb does not go out and goes into a dimmed state to notify the end of the life of the halogen bulb, and it is also possible to prevent the switching element of the high-frequency converter from being destroyed by the excessive current flowing at the end of the life of the halogen bulb. There is an effect that it is possible to realize a stable high-frequency lighting device for a halogen bulb.

Further, in addition to the above effects, when the commercial AC power supply fails in an emergency, power is supplied from the emergency DC power supply to the high frequency conversion means even if the halogen bulb is in a state where excessive current flows at the end of its life. Since the halogen bulb is turned on, there is an effect that a device that can reliably perform emergency lighting when it is turned on as emergency lighting in an emergency can be realized easily and inexpensively.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a high-frequency lighting device for a halogen bulb according to an embodiment of the present invention.

FIG. 2 is a diagram showing an input voltage waveform and a lamp current waveform of the rectifier circuit of the embodiment.

FIG. 3 is a circuit diagram showing a configuration of a high-frequency lighting device for a halogen bulb according to a conventional example.

FIG. 4 is a diagram showing an input voltage waveform and a lamp current waveform of a conventional rectifier circuit.

[Explanation of symbols]

 1 Commercial AC power supply 2 Emergency DC power supply 4 Rectifier circuit 5 Capacitor 15 Temperature fuse contact 16 Diode 30 Halogen bulb 40 High frequency inverter

Claims (3)

[Claims] 1. A rectifier circuit for rectifying AC of a commercial AC power source, a capacitor for charging an output of the rectifier circuit, and a halogen for converting a DC voltage across the capacitor into a high frequency voltage by using at least one switching element. A halogen comprising: a high-frequency converting means for lighting a light bulb; and a control means for monitoring the temperature of at least one switching element of the high-frequency converting means and limiting the output of the rectifying circuit based on the temperature. High frequency lighting device for light bulbs. 2. A rectifier circuit for full-wave rectifying the AC of a commercial AC power source, a capacitor for charging the output of the rectifier circuit, and a DC voltage across the capacitor having at least one switching element, converted to a high-frequency voltage. And a high-frequency conversion means for lighting the halogen bulb, and at least one switching element of the high-frequency conversion means, the contact of which is inserted in the input side of the rectifier circuit, the temperature of the switching element is monitored, and a certain set temperature is set. A high-frequency lighting device for a halogen light bulb, comprising: a temperature fuse that turns off the contact when the temperature reaches a temperature; and a diode connected in parallel to the contact of the temperature fuse. 3. An emergency DC power supply connected in parallel to the commercial AC power supply via a changeover switch, and power is supplied from the emergency DC power supply when the commercial AC power supply fails. The high frequency lighting device for a halogen bulb according to claim 1 or 2.