JP2001257095A - Soft starter device for lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft starter device for a lamp that has high preheating efficiency and increases the life of a lamp tube or a bulb. SOLUTION: The soft starter device comprises a rectifying current 20, a high frequency voltage generating circuit 30 between the two transistors Q1, Q2, a high frequency output transformer 40 having a primary and a secondary coil L11, L21, a first condenser C 31, which supplies an instantaneous high voltage to a lamp tube 51 by making resonance with the high frequency output transformer 40, a charging circuit and a switch Q3, and is equipped with a control circuit 50 which grounds the secondary coil 21 or enables an action of the secondary coil 21 in its normal state. At the initial stage, a filament is preheated with the switch Q3 'on' and disabling the function of the primary coil L11 and flowing only the electric current to the lamp tube 51. After a short period of charging, the switch Q3 is made 'off' and the lamp tube 51 is started by generating resonance between the first condenser C 31 and the high frequency output transformer 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft starter device, and more particularly, to a soft starter device for a fluorescent lamp, a power saving bulb, a mercury lamp, and the like, which operates according to a similar light emitting principle.

[0002]

2. Description of the Related Art In the principle of a conventional starting lamp such as a fluorescent lamp, an electronic ballast is used to start a fluorescent lamp tube having a high voltage and a high current generated by high frequency oscillation. At start-up, the voltage difference across the fluorescent lamp instantaneously rises to a high voltage exceeding 1000 V to start the lamp tube. If the lamp tube filament is not preheated, an instantaneous high voltage exceeding 2000 V is required for starting. Therefore, the filament of the fluorescent lamp must instantaneously withstand a high voltage exceeding 1000 V, and the inert ions generated by the preheating filament uniformly radiate to forcibly ignite the lamp tube and rapidly turn the filament on. Oxidizes, damages and degrades. As a result, the service life of the lamp is shortened. further,
When fluorescent lamps are discarded, the large amount of mercury filling them will cause environmental pollution problems.

In order to extend the service life of the lamp, the conventional method uses a frequency conversion circuit to lower the frequency before generating a high voltage, thereby generating a low voltage instead of a high voltage. Was. At the same time, a low current flows through the preheating filament, and after a certain period of time, a high voltage is generated and the fluorescent lamp tube is turned on.

[0004]

The disadvantages of the above-mentioned conventional method are obvious, in that the preheating is insufficient because both the voltage and the current are suppressed. On the other hand, electric lamps are equipped with a plurality of fluorescent lamp tubes, each of which has a different minimum voltage required for its own lighting, so that some fluorescent lamp tubes have a low voltage without being preheated. There is a possibility that it will be forcibly turned on under the following conditions. Since the conventional frequency conversion type soft starter cannot completely stop the application of voltage during preheating of the filament, some fluorescent lamp tubes are turned on, and the shortening of the life cannot be completely prevented. Was.

[0005] In view of the above problems, the present invention provides a soft starter device which does not supply a voltage to start a fluorescent lamp tube and does not suppress current during preheating of a filament. An object of the present invention is to reduce the number of built-in electronic components, simplify the structure of the device, improve the efficiency, and make the device widely applicable to a multi-tube fluorescent lamp.

It is an object of the present invention to prevent voltage from being applied to the primary coil by initially grounding the secondary coil and temporarily disabling the function of the primary coil coupled thereto at the initial stage of power supply. At this time, the current coming from the high-frequency voltage generation circuit flows into the lamp tube or bulb to preheat them, and after a certain period of time,
An object of the present invention is to provide a soft starter device that increases the life of a lamp tube or a bulb by supplying a normal voltage.

It is another object of the present invention to provide a high efficiency and low cost soft starter device configured to start multiple lamp tubes or bulbs simultaneously.

[0008]

According to one aspect of the present invention, there is provided a rectifier circuit connected to an AC power supply for converting an AC voltage into a DC voltage serving as a starting signal. A high-frequency voltage generating circuit connected to the rectifier circuit and including two transistors and an output capacitor for generating a high-frequency voltage; and a primary coil connected to the high-frequency voltage generating circuit and magnetically coupled to each other. And a secondary coil, one terminal of the primary coil is connected to one terminal of the output capacitor,
The other terminal of the primary coil and one terminal of the secondary coil are connected to both ends of the lamp tube, respectively, and are connected to both ends of the lamp tube to cause resonance with the high frequency output transformer. A first capacitor for supplying an instantaneous high voltage to start the lamp tube, and a charging circuit and a switch connected to the other terminal of the secondary coil, and a charging circuit in an initial stage of power supply by an AC power supply. The secondary coil connected to the switch is grounded by supplying the charging current from and turning on the switch.
When the primary coil cannot operate normally, current flows from the output capacitor to the lamp tube to preheat the filament of the lamp tube, and after the charging period has elapsed, the switch is turned off to operate the secondary coil normally. And a control circuit for causing the lamp tube to start smoothly by causing resonance with the first capacitor.

According to a second aspect of the present invention, in the soft starter according to the first aspect, the output current of the high-frequency voltage generating circuit for preheating the filament of the lamp tube is not suppressed.

According to a third aspect of the present invention, in the soft starter device according to the first aspect, when the filament is preheated by an output current of the high frequency voltage generating circuit, the high frequency output transformer applies a voltage to the lamp tube. Is not supplied.

According to a fourth aspect of the present invention, in the soft starter device according to the first aspect, the switch is a transistor.

According to a fifth aspect of the present invention, in the soft starter device according to the first aspect, the switch includes a relay and a transistor.

According to a sixth aspect of the present invention, in the soft starter device according to the first aspect, the switch is a temperature switch.

[0014]

FIG. 1 is a circuit diagram showing a soft starter device according to a first embodiment of the present invention. As shown in FIG. 1, the soft starter device includes a rectifier circuit 20, a high-frequency voltage generation circuit 30, a high-frequency output transformer 40, a first capacitor C31, and a control circuit 50. The rectifier circuit 20 is connected to the AC power supply Sac and includes a rectifier bridge circuit 10 used to convert an AC voltage into a DC voltage output from the node A. A start signal is output. High frequency voltage generating circuit 30
Are connected to the rectifier circuit 20 and generate two high-frequency AC voltages by resonance.
Q2 is provided. High frequency AC voltage is output capacitor C
1 is applied to the high-frequency output transformer 40. The high-frequency output transformer 40 is connected to the output capacitor C1 of the high-frequency voltage generation circuit 30, and includes a primary coil L11 and a secondary coil L21 magnetically coupled to each other. One terminal of the primary coil L11 is connected to one terminal of the output capacitor C1. Primary coil L11
And the other terminal of the secondary coil L21 are connected to both ends of the fluorescent lamp tube 51, respectively. further,
The first capacitor C31 is also connected to both ends of the fluorescent lamp tube 51. The first capacitor C31 and the high-frequency output transformer 40 constitute an LC resonance circuit that generates a high voltage and turns on the lamp tube 51.

At the initial stage when power is supplied from the AC power supply Sac, a part of the charging current flows from the DC power supply Vcc to the base of the power transistor Q3 via the charging circuit including the capacitor C2 and the resistor R1 of the control circuit 50. Therefore, since the power transistor Q3 is turned on, LC resonance by the high-frequency output transformer 40 and the first capacitor C31 cannot occur. In order to prevent the transistor Q3 from being damaged, a Zener diode Z1 having a function of stabilizing a voltage is used. When the transistor Q3 is turned on,
The potential of one terminal of the secondary coil L21 is reduced to substantially the ground potential, that is, the secondary coil is grounded. At this time, the primary coil L11 magnetically coupled to the secondary coil L21 lowers the magnetic induction from ² mH to about 10 ^-2 mH. Therefore, LC resonance by the high-frequency output transformer 40 and the first capacitor C31 cannot occur. As a result, no high voltage is supplied to the fluorescent lamp tube 51. However, the capacitor C1 of the high-frequency voltage generation circuit 30
The current output from the lamp flows through the primary coil L11 to the fluorescent lamp tube 51 to preheat the filament of the lamp tube 51. At an earlier stage when power is supplied, no voltage is applied to the primary coil L11, and only the current flows through the lamp tube 5.
1 to preheat the lamp tube. On the other hand, the primary coil L11 has a small amount of inductance (about 10 ^-2 mH) and is not completely short-circuited. Therefore, mercury (not shown) contained in the fluorescent lamp tube 51 is
Dramatic volatilization that darkens 1 can be prevented. Further, the charging current flowing through the RC charging circuit gradually decreases as the charging time increases. When the charging time reaches about 1.5 seconds, the charging current becomes so small that transistor Q3 cannot be driven. In other words, the transistor Q3 is turned off, the high-frequency output transformer 40 operates normally, and it becomes possible to cause LC resonance with the first capacitor C31. At this time, a high voltage is generated and supplied to the fluorescent lamp tube 51 to light it.

Compared with the prior art, the soft starter device of the present invention does not suppress the current for preheating, so that the preheating efficiency can be improved. Further, since no voltage is applied to the fluorescent lamp tube during the preheating period, the fluorescent lamp tube is not forcibly turned on. Therefore, the life of the fluorescent lamp tube can be effectively extended.

FIG. 2 is a circuit diagram showing a soft starter device according to a second embodiment of the present invention. Unlike the first embodiment shown in FIG. 1, whether or not to supply a high voltage to the lamp tube 51 is determined based on whether or not the power transistor Q3 is in the ON state. In the second embodiment of the present invention, in order to determine whether to supply a high voltage to the lamp tube 51, a relay R21 and a small power transistor (small) are used.
power transistor) Q3 is used. The operation for generating the high voltage shown in FIG. 2 is the same as the operation shown in FIG. 1, and therefore the description is omitted here. Hereinafter, a method of supplying a high voltage to the fluorescent lamp tube will be described. Capacitor C
When a current flows through a charging circuit composed of R2 and the resistor R1, and charges the capacitor C2, a part of the charging current turns on the small power transistor Q3 and pulls the switch of the relay R2 downward. At this time, the secondary coil L21 is connected to the diode D
1, and the function of the primary coil L11 is disabled. In this state, only the output current flowing from the capacitor C1 flows into the fluorescent lamp tube 51 to preheat the filament. After the charging period, the charging current becomes very small, and the transistor Q3 cannot be driven. In other words, at this time, the transistor Q3 is turned off, and by opening the switch of the relay R2, the primary coil L11 and the secondary coil L21 can return to the normal state. As a result, the primary and secondary coils L11, L2
1 and the first capacitor C31 can cause LC resonance, and a high voltage can be supplied to the fluorescent lamp tube 51 to start the lamp tube 51. As described above, the switch used to control whether to supply a high voltage to the fluorescent lamp tube is not limited to one type. For example, the supply of a high voltage to the fluorescent lamp tube can be controlled by detecting a temperature change of the electronic component during the charging period using a temperature switch.

FIG. 3 is a circuit diagram showing a soft starter device according to a third embodiment of the present invention. As shown in FIG. 3, the first LC resonance circuit includes a primary coil L11, a secondary coil L21, and a first capacitor C31 for the first fluorescent lamp tube 51. In the secondary coil L21,
In order to control whether or not to supply a high voltage to the first fluorescent lamp tube 51, a power transistor Q3 is connected via a diode D1. On the other hand, the second LC resonance circuit includes a primary coil L12, a secondary coil L22, and a second capacitor C32 for the second fluorescent lamp tube 52. The power transistor Q3 is connected to the secondary coil L22 via a diode D2 to control whether or not to supply a high voltage to the second fluorescent lamp tube 52.

FIG. 4 shows a fourth embodiment of the present invention.
It is a circuit diagram showing a soft starter device provided with four fluorescent lamp tubes. As shown in FIG. 4, the secondary coils L21,
L22, L23, and L24 each have a fluorescent lamp tube 5
Diodes D1, D2, D3 and D4 are connected to control whether or not to supply a high voltage to 1, 52, 53 and 54. The operation of the soft starter device of this embodiment is the same as the operation of the other embodiments described above. FIG.
4 and FIG. 4, the soft starter device of the present invention can be applied to a plurality of fluorescent lamp tubes without changing the main structure.

Although the present invention has been described by way of preferred embodiments as an example, it goes without saying that the present invention is not limited to the embodiments disclosed above. On the contrary, it will be apparent to those skilled in the art that various modifications and similar arrangements can be made without departing from the scope and spirit of the invention. For example, the transistor Q3 serving as a switch may be replaced with a conventional temperature switch, and the diode D1 for preventing damage may be omitted. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a soft starter device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a soft starter device according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a soft starter device according to a third embodiment of the present invention.

FIG. 4 is a circuit diagram showing a soft starter device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 20 rectifier circuit 30 high-frequency voltage generation circuit 40 high-frequency output transformer 50 control circuit 51, 52, 53, 54 fluorescent lamp tube C1 output capacitor C2, C31, C32, C33, C34 capacitor D1, D2, D3, D4 diode L11, L12 , L13, L14 Primary coil L21, L22, L23, L24 Secondary coil Q1, Q2 Transistor Q3 Power transistor R1 Resistance R2 Relay Sac AC power supply Vcc DC power supply Z1 Zener diode

Claims (6)

[Claims] 1. A rectifier circuit connected to an AC power supply for converting an AC voltage into a DC voltage serving as a start signal, a rectifier circuit connected to the rectifier circuit, two transistors and an output capacitor for generating a high-frequency voltage. A high-frequency voltage generating circuit, comprising a primary coil and a secondary coil connected to the high-frequency voltage generating circuit and magnetically coupled to each other, one terminal of the primary coil being connected to one terminal of the output capacitor; A high-frequency output transformer in which the other terminal of the primary coil and one terminal of the secondary coil are respectively connected to both ends of the lamp tube; and a high-frequency output transformer connected to both ends of the lamp tube and resonating with the high-frequency output transformer And a first capacitor that supplies an instantaneous high voltage to start the lamp tube, and is connected to the other terminal of the secondary coil. An electric circuit and a switch are provided, and a charging current is supplied from a charging circuit in an initial stage of power supply by an AC power supply, and a secondary coil connected to the switch is grounded by turning on the switch. At that time, the primary coil operates in a normal state. Unable to do so, current flows from the output capacitor to the lamp tube to preheat the filament of the lamp tube, and after the charging period has elapsed, turns off the switch and operates the secondary coil in the normal state to allow the first capacitor to operate. A soft starter device for a lamp, comprising: a control circuit for causing resonance to occur to smoothly start the lamp tube. 2. The lamp soft starter according to claim 1, wherein the output current of the high-frequency voltage generating circuit for preheating the filament of the lamp tube is not suppressed. 3. The soft starter device for a lamp according to claim 1, wherein the high frequency output transformer does not supply a voltage to the lamp tube when the filament is preheated by the output current of the high frequency voltage generating circuit. 4. The soft starter for a lamp according to claim 1, wherein said switch is a transistor. 5. The soft starter for a lamp according to claim 1, wherein said switch comprises a relay and a transistor. 6. The soft starter for a lamp according to claim 1, wherein said switch is a temperature switch.