JPH02210792A - Fluorescent lamp lighting control device - Google Patents

Abstract

PURPOSE:To lengthen a life of a fluorescent lamp and to save power consumption by properly controlling timing of preheating and tube voltage impression at the time of lighting the fluorescent lamp. CONSTITUTION:In a magnet leakage transformer T1, a primary winding P is connected to a high-frequency power supply, and secondary winding S1 and S2 are wound to a prescribed number of winding, wherein S1 supplies power for preheating a filament and lighting fluorescent lamps FL1, FL2 and S2 supplies power to a timer circuit TM. Then, by the timer circuit TM using time constant of differential circuits R4 and C3, DC is made conductive to the windings L1 and L2 for controlling a magnet amplification type transistor T2 at an early period of conduction to reduce impedance of the winding M to be controlled for preheating the filament by a transformer T3 for heating. After preheating, conduction to the windings L1 and L2 for control is cut so as to heighten impedance of the winding M to be controlled, stop preheating and also impress raised tube voltage on a fluorescent lamp. Thereby, power consumption is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fluorescent lamp lighting control device that controls the timing of filament preheating and tube voltage during lighting of a fluorescent lamp.

(Prior art) A phosphor that emits light of a desired color is coated on the inner wall of a glass tube, and a hot cathode such as a tungsten wire coated with an electron emitting chamber is provided at both ends of the glass tube. Fluorescent lamps sealed with gas or krypton gas are widely used for lighting.

To turn on this type of fluorescent lamp, first energize the tungsten wires at both ends, which will serve as the electrodes, to preheat them.
After it becomes red hot enough to emit thermionic electrons, a discharge tube voltage is applied between both electrodes to discharge the sealed gas, and the phosphor is further exposed to ultraviolet light generated by the discharge of mercury vapor. It is excited to emit colored light for illumination.

For this reason, glow lighting tubes equipped with bimetallic contacts are usually used to preheat fluorescent lamps, and current limiters are used to prevent excessive current due to negative resistance during discharge.

In this lighting method using glow lamp tubes, the filament is energized by bimetal activation due to the heat generated by the glow discharge when the power is turned on, so it takes time to turn on the lamp, and it is not affected by the outside temperature or takes time to turn on. There is a problem that the time for this process varies, and for this reason, a rabbit start method has been adopted in which a tube voltage for discharge is applied at the same time as the filament is preheated.

(Problem to be Solved by the Invention) In the rabbit start method described above, preheating and application of tube voltage are performed at the same time, so it has the advantage of a quick start time, but the tube voltage is applied before the filament is sufficiently preheated. Since the discharge is started at the same time, a large stress is applied to the filament, which has the disadvantage of shortening its life.

Furthermore, since the filament continues to be energized even after discharge has started and the fluorescent lamp is turned on, there is a problem in that power consumption is large.

The present invention was made in view of such problems,
The purpose is to provide a fluorescent lamp lighting control device that extends the life of the fluorescent lamp and saves power by appropriately controlling the timing of preheating and tube voltage application during lighting of the fluorescent lamp.

(Means for Solving the Problems) According to the present invention, in a fluorescent lamp lighting control device that applies a tube voltage for discharge after preheating a filament serving as an electrode to turn it on, the secondary side is provided with a tube voltage for the tube voltage. A magnetic leakage transformer for a power supply having a winding and a winding for a DC power supply, a transformer for a heater that transforms power supplied from the winding for the tube voltage for preheating a filament, and a transformer for the heater. A controlled winding of a magnetic amplification transformer connected in series with the primary winding, a rectifier that rectifies the power supplied from the winding for the DC power supply, and a DC power supply from the rectifier after the preheating time of the filament has elapsed. A fluorescent lamp lighting control device is provided that includes a timer circuit that supplies voltage to a control winding of the magnetic amplification transformer.

(Function) In the present invention, a timer circuit using the time constant of an integrator circuit applies direct current to the control winding of the magnetic amplification type transformer at the initial stage of energization to reduce the impedance of the controlled winding a, thereby reducing the impedance of the heater winding. The filament is preheated by a transformer, and after the preheating, the control winding is turned off and the impedance of the controlled winding is increased to stop preheating and apply the increased tube voltage to the fluorescent lamp.

(Example) Next, an example of the present invention will be described in detail using the drawings.

The drawing is a circuit diagram of a control device showing an embodiment of the present invention, and is used for lighting fluorescent lamps FLI and FL2.

In the figure, TI is a magnetic leakage transformer, a secondary winding P is connected to a high frequency power source, and has secondary windings S1 and s2 wound with a predetermined number of turns. S2 supplies power for lighting the lamp to a timer circuit, which will be described later, and has constant current characteristics against load fluctuations.

T2 is a magnetic amplification type transformer, and the winding M is the controlled winding.
1 has windings L1 and L2 that serve as control windings, and winding L
By changing the magnetization characteristics of the iron core by passing DC current through L and L2, the glue actance of the winding M is changed,
The current passing through the winding M can be controlled by varying the impedance.

Tg is a heater transformer, which supplies power to the negative winding P3 and transforms the secondary windings sgt, S! The filaments of the fluorescent lamps FLI and FL2 are preheated by the electric power from G2.5&5, and the secondary winding P3 and the winding M are connected in series, and the electric power is supplied from the primary winding P of the transformer T1. is configured to be supplied with

TM is a timer circuit, and the secondary winding S of the transformer T1
This circuit operates using DC power obtained by rectifying the power from transistors Q1. Q2゜Q3 and R4 which becomes an integrating circuit. In addition to C3, it has resistors, capacitors, etc.
Winding of transformer T2, 1. By temporally controlling the direct current to L2 and changing the impedance of the winding M, the fluorescent lamp F
L1. This controls the filament preheating of FL2 and the supply of tube voltage.

Here, when the power from the winding S2 rectified by the diode bridge D1 is supplied to the timer circuit TM,
It is smoothed by capacitor C1, but transistor Q3
A capacitor C3 is connected to the base of the transistor Q, and since there is R4 which acts as a resistance of the integrating circuit, the rise of the base voltage is delayed within a predetermined time immediately after the switch is turned on, and the transistor Q
3 is in the off state. Therefore, when transistor Q2 is turned on, transistor Q1 is also turned on, and winding L1. of transformer T2 is turned on. The structure is such that by passing a current through L2, the magnetization of the iron core is strengthened and brought into a saturated state, thereby reducing the impedance of the M winding. Note that, after a predetermined time has elapsed since the switch is turned on, the transistor JQs is turned on due to the rise in the terminal voltage of the capacitor C3, so that, contrary to the above, the transistor Q2. Q is turned off, thus releasing the saturation state of the transformer T2 and increasing the impedance of the M winding of the controlled winding.

Next, the operation of this embodiment configured as described above will be explained.

Fluorescent lamp FL1. To light up FL2, first turn on switch Sw.
, the timer circuit TM is supplied with power from the winding S2 as described above, and the winding LL of the transformer T2 is
, t,2, and the impedance of the winding M decreases, causing the transformer T connected in series to
A sufficient current passes through the primary winding S1 of g, and the secondary winding Sg
1°S52. Heat the filaments connected to S, 5g, respectively. Then, since the transformer T3 takes power for heating the filament from the primary winding S1 of the transformer T1, the terminal voltage of the primary winding S1 decreases due to the characteristics of the magnetic leakage transformer, and is controlled to be below the discharge starting voltage of the fluorescent lamp. It turns out.

Next, when a predetermined period of time has elapsed after the switch Sw is turned on, the timer circuit TM operates the winding L1. The power supply to L2 is stopped, the impedance of the winding M increases, and the power supply to the transformer T5 decreases, and the Isogo voltage of the primary winding S1 of the transformer T1 rises to the voltage required to start discharging. Thermionic electrons are released from the filament, which has been preheated, and the fluorescent lamp begins to discharge.

During this time, the capacitor C5 of the timer circuit TM is charged and maintains a predetermined terminal voltage, so the operation of the transistors Ql, Q2, and Q3 causes the transformer T
The power supply to No. 2 #iLt and L2 remains stopped, and the lighting of the fluorescent lamp continues.

In addition, when turning off the switch Sw and turning off the fluorescent light,
The electric charge stored in the capacitor C3 of the timer circuit TM is transferred to the diode D5. The voltage is discharged through the resistor R1, etc., and the terminal voltage of the capacitor C3 is kept at zero.

Although the present invention has been described above with reference to the embodiments described above, various modifications can be made within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

(Effects of the Invention) According to the present invention, the semiconductor 0
By controlling the timer circuit, the impedance of the controlled winding of the magnetic amplification transformer is reduced in the initial stage of energization, the heater transformer is activated to preheat the filament, and the voltage applied from the magnetic leakage transformer is lower than the discharge start voltage. Then, the timer circuit increases the impedance of the controlled winding to cut off the power to the heater transformer, and the magnetic leakage transformer increases the voltage applied to the fluorescent lamp to turn it on. By setting the time constant, the timing between preheating the filament and applying the tube voltage can be properly controlled. Therefore, the tube voltage is applied after sufficient preheating, which causes abnormal stress on the filament. The effect of maintaining a long lifespan of fluorescent lamps can be achieved without adding any additional energy. Furthermore, since the preheating of the filament is completely stopped after the fluorescent lamp is turned on, the electric power used while the lamp is turned on can be reduced, which has the advantage of saving energy.

In addition, a flashing test of a fluorescent lamp (lighting on for 30 seconds, 159
When the circuit of this example was used to perform a flashing test (second pause), compared to the same type of flashing test using the conventional rabbit start method,
A lifespan more than 5 times longer has been achieved.

[Brief explanation of the drawing]

The drawing is a circuit diagram of an embodiment of the present invention. T1...Magnetic leakage transformer, T2-...Magnetic amplification transformer, T5...Heater transformer, TM...Timer circuit, FLl, FL2...Fluorescent lamp.

Claims (3)

[Claims] (1) A fluorescent lamp lighting control device that applies a tube voltage for discharge after preheating a filament serving as an electrode to turn it on, which has a winding for the tube voltage and a winding for a DC power source on the secondary side. A magnetic leakage transformer for power supply, a heater transformer that transforms the electric power supplied from the tube voltage winding for preheating the filament, and a magnetic amplification type connected in series with the primary winding of the heater transformer. a controlled winding of the transformer; a rectifier that rectifies the power supplied from the DC power supply winding; and after the preheating time of the filament elapses, the DC voltage from the rectifier is applied to the control winding of the magnetic amplification transformer. What is claimed is: 1. A fluorescent lamp lighting control device comprising: a timer circuit that supplies (2) The energization control of the timer circuit is performed by applying direct current to the control winding of the magnetic amplification transformer at the initial stage of lighting, reducing the impedance of the controlled winding, preheating the filament by the heater transformer, and applying voltage. The fluorescent lamp according to claim 1, characterized in that after the preheating, the control winding is de-energized and the tube voltage from the magnetic leakage transformer is applied to the fluorescent lamp. Lighting control device. (3) Claims (1) and (3) wherein the timer circuit is a semiconductor circuit using a time constant of an integrating circuit.
2) The fluorescent lamp lighting control device described above.