JPS5854547A - Lighting device for electric-discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp lighting device that lights a discharge lamp using high frequency and is dimmable.

The AC power supply is controlled by phase control, etc., and the DC voltage obtained by full-wave rectification of the output is input to an inverter, and a discharge lamp such as a fluorescent lamp is lit at a high frequency of 2 to 3 KHz or higher using an inverter. Attempts have been made in the past to perform light control by changing the angle because it provides good light control with less flicker. As such a device, the device shown in FIG. 1 has been known.

In the first figure of Jin, lt! AC power supply, 2 is AC power supply 1
This is a dimming device that controls the voltage phase of the thyristor (2), a bidirectional thyristor 3, and a control device 14 that controls the conduction start phase t of the bidirectional thyristor 3.

In addition, 6 is an inverter, here it is constructed with a push-pull type transverse inverter having a resonant circuit.
Its input is a DC voltage obtained by rectifying the output of the dimmer 2 by a full-wave rectifier 115.

The inverter 6 has an output winding 118g, a collector winding 8c1.
8c3, pace feedback winding 8b, filament winding 8f,
, 8f, and an output transformer 8 composed of a leakage transformer and a switching transistor 9m,
9b, high frequency choke coil 10. Resonant capacitor 11
, bias resistors 12a, 12b, etc.

In other words, the connection point with the collector windings 8cl and eeel is connected to the positive output end of the full-wave rectifier 5. The positive side output end of this full-wave rectifier *5 is also connected to the bases of switching transistors 9m and 9b via negative resistances 12m and 12bl, respectively. One end of each collector winding II 8es e 8cl is connected to the collectors of switching transistors 9m and 9b, respectively. The terminals of the switching transistors 9m and 9b are respectively connected to both ends of the pace feedback winding 118b. A resonance 1 capacitor 11 is connected between each end of the collector winding 8cl @Be. A switching transistor 9a.

Both emitters of 9b are connected to the negative output end of the full-wave rectifier fIt5 via a high-frequency choke coil 10.

Thus, the Tagata transformer 8, the switching transistors 9m and 9b, the high frequency choke coil 10, the resonant capacitor 11, and the bias resistor 12a.

12b and a plurality of impurities 6 are formed.

Also, the filament winding 8f of the output transformer 8.

8fl is connected to preheating electrodes 7ft, 7f, of the discharge lamp 7. As this discharge lamp 7, for example, a fluorescent lamp is used.

The output transformer 8 is also provided with an auxiliary winding 8.
Both ends of this auxiliary winding 8 are connected to the input end of a rectifier circuit 14. A capacitor 16 is connected between the positive and negative output terminals of this rectifier circuit 14, and the positive output terminal is connected via a diode 15 to the positive output terminal of the full-wave rectifier fil:5. There is. The negative output terminal of the full-wave rectifier [15] and the negative output terminal of the rectifier circuit 14 are commonly connected.

Thus, the auxiliary winding 1II8, together with the rectifier circuit 14, the diode 15, and the capacitor 16, constitutes an auxiliary DC power supply.

In the apparatus configured as described above, when the AC power supply 1 is turned on, a full-wave rectified voltage is generated at the output end of the full-wave rectifier 5, as shown in FIG. The bidirectional thyristor 3 changes its conduction start phase to, for example, the second phase by a signal from the control device 4.
When the phase is set to 01 as shown in the figure), DC power is supplied to the inverter 6 via the full-wave rectifier 15 for a period of TI. A bias resistor 12a is connected to the bases of the switching transistors 9m and 9b of the inverter 6 during the period TI.
.

12b) is supplied with a pace current and the pace return winding 8b
etc.), the well-known method (self-oscillation is performed, a high frequency voltage is generated in each winding of the output transformer 8, and the preheating electrode 7 fl *
Preheat by 7 fmt and turn on the discharge lamp 7.

Further, the degree of dimming is performed by changing the conduction start phase 01 by the dimming device [12].

During the TI period, DC power is not supplied from the dimmer fk2 to the inverter 6, and during the TI period when DC power is supplied from the dimmer 2, the voltage across the auxiliary winding 8 is changed to the rectifier circuit. The capacitor 16 is charged via the capacitor 14 and its terminal voltage Vcp is supplied to the input of the inverter 6 during the Tx period, and the input voltage of the inverter 6 is as shown in FIG.
As shown in Table 6b), the terminal voltage Vcp of the capacitor 16 is set so that the discharge lamp 7 is turned off during the TI period when the voltage of the capacitor 16 is applied to the inverter 6. goes out, and the preheating electrode 7 of the discharge lamp 7
f1* 71B is filament winding 1! 8ft t
It is preheated by 8ft, and the preheating voltage is as shown in Figure 2 (6).
K as shown in .

Note that FIG. 2(c) shows the discharge current of the discharge lamp 7.

As described above, by appropriately setting the terminal voltage Yap and capacity of the capacitor 16, the preheating electrodes 7f, 7fs can be preheated even during the rest period of the discharge current, and the dimming of the discharge lamp 7 can be performed. It is possible to make the process smooth and to suppress the deterioration of the electrodes of the discharge lamp 7, thereby extending the life of the discharge lamp 7.
-It is something that we aim to achieve.

However, in such conventional discharge lamp lighting devices,
The DC voltage from the dimmer [2 becomes low and the inverter 60
When the input voltage reaches the voltage of the capacitor 16, the voltage of the capacitor 16 increases due to fluctuations in the AC power supply 1, etc.
Then, the discharge of the discharge lamp 7 is likely to stop and then continue.

If the discharge continues, dimming cannot be performed smoothly.The charge in the capacitor 16 will suddenly discharge.
The ebb and flow voltage suddenly decreases, and the preheating electrode 7f,
, 7f, cannot be preheated.

Furthermore, when the voltage of the capacitor 16 is set low to prevent continuation of discharge, the input voltage of the inverter 6 decreases, the voltage of the filament windings 8f, , 8f decreases, and the preheating electrodes 7f1, 7f are preheated. You won't be able to do it enough.

Furthermore, the capacitor 16 tends to be large in size, requiring a large capacity electrolytic capacitor, and the life of the electrolytic capacitor is short.

The present invention provides a discharge lamp lighting device that eliminates the above-mentioned conventional drawbacks and performs smooth dimming by performing sufficient preheating during the period when DC power is supplied to the inverter from the dimming device. The purpose is to

Examples of the discharge lamp lighting device of the present invention will be described below.
Explain based on the surface. Fig. 3 is a circuit diagram showing the configuration of one embodiment of the same. I will focus on the parts that differ from the above.

In FIG. 3, an AC power supply 1, a light control device 2, a bidirectional thyristor 3, a control device 4, a full-wave rectifier [15, an inverter 6, a discharge lamp 7, an output transformer 8, switching transistors 9m, 9b, High frequency choke coil 10. The parts including the 11:7 capacitor 11 and the ear resistors 12m and 12b are the same as those shown in FIG. 1. In this invention, a preheating control circuit 17 and a preheating circuit 23 are newly added.

In other words, since the output voltage of the preheating control circuit 17 changes according to the input voltages of the first-class power supply 18 obtained by step-down rectifying the output of the dimmer 2, the trigger circuit 19, and the inverter 6, the voltage detection circuit 20 and this A delay circuit 21 whose delay time changes depending on the output voltage of the voltage detection circuit 20 and an output circuit 22 are formed.

In addition, a transistor 24° oscillation circuit 2 is used to turn on and off the power supply of the oscillation circuit 25 according to the signals from the preheating circuit 23 and the output circuit 22.
The preheating transformer 27 has filament windings 27fl and 27fg''ft, and generates an alternating current voltage by switching the transistor 26.

Next, the operation of the discharge lamp lighting device according to the invention that has been accomplished as described above will be explained. When the AC power supply 1 is turned on, the conduction start phase of the bidirectional thyristor 3 is controlled by a signal from the control device fi14. For example, when the phase is set to θ1 shown in FIG. DC power is supplied for a period T1 via the device ff1E5.

During this period of Ts, the inverter 6 has a bias resistance of 12 m,
12b, a pace current is supplied, and the well-known self-excited oscillation is performed by the action of the pace feedback winding 8b, and a high voltage is generated in each winding of the output transformer 8, and the discharge lamp 7 is lit.

Further, in the preheating control circuit 17, a DC power supply 18 is applied to each circuit, and the input voltage of the inverter 6 is applied to a trigger circuit 19 and a voltage detection circuit 20. For example, if the conduction start phase of the dimmer 12 is #1 shown in 4th Z (a)
If so, the trigger circuit 19 generates a trigger signal at phase a5 and applies it to the delay circuit 21 to start the delay operation.

The voltage detection circuit 20 generates an output voltage according to the average value of the DC voltage of the inverter 6 and applies it to the delay circuit 21 . After the delay time elapses in the delay circuit 21, an output occurs at a phase of θmlk, and the output is transmitted to the preheating circuit 23 via the output circuit 22.
is applied to The output voltage of the output circuit 2 at this time is as shown in FIG. 4 (b).

The transistor 24 becomes conductive depending on the output of the output circuit 22.

Then, the DC power supply 18 is applied to the oscillation circuit 25 to start oscillation, and the output of the DC power supply 18 causes the transistor 26 to switch, causing the preheating transformer 271C to generate an AC voltage.

Therefore, as shown in FIG. 4(c), the DC voltage is applied from the light control device 2, and the AC voltage is applied to the preheating transformer 27 for a period Ts of phase 0s to 0o during which the oscillation circuit 25 is oscillating. is generated, and the preheating electrode 7fl + 7fmt- is preheated by the filament winding 27fx+27f.

That is, when the conduction start phase of the light control device 2 is θl, θ
The discharge lamp 7 is lit for a period of T1 from l to 0o, and the preheating electrodes 7fl and 7fs are preheated for a period of T3 from θ3 to θ·tre out of the lighting period T10.

On the other hand, if the conduction start phase of the light control device 2 is delayed to a phase of θ3 shown in 4E, the period during which the DC voltage is applied to the inverter 6 is as short as T4, and the average voltage decreases.

When the average input voltage of the inverter 6 decreases, the output voltage of the voltage detection circuit 20 increases and the delay time of the delay circuit 21 becomes shorter than K Ts as shown in FIG. When the phase becomes 04, the preheating time T・
becomes long as shown in FIG. 4(f).

In this way, the period during which DC power is supplied to the diimperature whose conduction start phase of the dimmer &2 is slow is short, and when the period of inactivity of the sheep electric lamp 7 becomes long, the temperature of the preheating electrode 7fs * 7f is going to decrease. The temperature of the preheating electrodes 7f1 and 7fs can be kept almost constant as the preheating start phase appears earlier and the preheating period becomes longer, and during the period when DC power is not supplied from the dimmer 2 to the inverter 6, the discharge lamp 7t-
You can pause the light and perform smooth dimming.

(9) Setting the preheating end phase to a phase where the voltage of the AC power supply 1 becomes Ov is effective in widening the dimming range.

FIG. 5 shows a specific circuit diagram of the embodiment shown in FIG.

In this FIG.
, DC power supply 18, )! The J trigger circuit 19 is similar to that shown in FIG. 3, and the trigger circuit 19 includes a capacitor 19a, a resistor 19b,
19c, 19d,) Lannostar 19・, Diode 19
It is formed by f.

The voltage detection circuit 20 includes resistors 20a, 20b, and 20c.

It is formed by a 20d1 capacitor 20. and a transistor 20f. The delay circuit 21 is formed of a resistor 211° 21d, a capacitor 21b, a Zener diode 21e, and a transistor 21. The output circuit 22 is formed of a resistor 22m.
, 22b, 22d and a transistor 22c. 23 is a preheating circuit, and 24 is a transistor.

When the AC power supply 1 is applied to the discharge lamp lighting device constructed as described above and shown in FIG. A DC power supply 18 obtained by step-down rectifying the output is the preheating control circuit 1.
7, and the conduction start phase of the light control device 2 is as shown in FIG. 4 (1
When the trigger circuit 19 is set to θ shown in 1), the transistor 19 becomes conductive once in the phase of the differential circuit TE01 of the capacitor 191L and the resistor 19b to generate a trigger signal.

This trigger signal discharges the charge in the capacitor 21b of the delay circuit 21 via the diode 19f and the transistor 19, resets the delay circuit 21t, and starts the delay operation.

The voltage detection circuit 20 includes a resistor 20a and a capacitor 20.
The integration circuit detects the average voltage applied to the Inno Kai-Yu 6, and the transistor 20f amplifies it and outputs it.
When the applied voltage t≦higher in Inno 4-6, the output becomes lower.

In the delay circuit 21, the resistor 2 is connected to the output voltage of the voltage detection circuit 20.
The capacitor 21kl is charged through the capacitor 1&, and when its terminal voltage reaches the operating voltage of the Zener diode 21c, the transistor 21e iE becomes conductive and the output becomes rLJ.

Here, the delay time of the delay circuit 21 is the capacitor 21b
It changes depending on the output voltage of the sb voltage detection circuit 20 at the time when the terminal voltage reaches the operating voltage of the Zener diode 21c. That is, the higher the output voltage of the voltage detection circuit 200, the faster the charging speed and the shorter the delay time.

When the output of the delay circuit j321 completes the delay operation and decreases to rLJ, it is inverted by the output circuit 22, the transistor 24 of the preheating circuit 23 becomes conductive, and the preheating circuit 23 operates. Here, as shown in Fig. 4 (a), (b), and (C), K
, the delay time 7b of the delay circuit 21 when the conduction start phase of the dimmer fIL2 is Set! 'l', and the preheating time is T3 from the phase θ (lot).

On the other hand, as shown in FIG. 4(d), (・), and (f), the conduction start phase of the light control device 12 is delayed, and the voltage of the voltage detection circuit 200A increases when the θ field is reached, so there is a delay. circuit 2
The delay time for phase 1 is short, T1, and the preheating time is long, T for phases 0 to 00. In this way, the above operation t- can be realized.

In the above embodiment, the preheating end phase is controlled by the AC power source 1.
Although the temperature of the preheating electrodes 7fs and 7fl was controlled to be constant by changing the preheating start phase according to the conduction start phase of the dimmer device [12], the temperature of the preheating electrodes 7fs and 7fl was controlled to be constant. As shown in the figure, the preheating start phase t may be fixed, and the preheating end phase may be changed depending on the conduction start phase of the sound dimming device 2.

In other words, as shown in FIG. 6, when the conduction start phase of the light control device 2 is θ, the preheating start phase is θ-, the preheating end phase is 07, and the period T from θ to θ1 is This is a preheating period.

Ninth, the conduction start phase of the light control device 2 is delayed and becomes θ-,
Period k Two during which DC power is supplied to the inverter 6
If it is shortened to 11, the preheating start phase is fixed at 0.The preheating end phase is delayed and the preheating period becomes 'I'1.
The length becomes m.

This operation causes the light control device fi12 to
The temperature of the preheating electrodes 7f, , 7fρ can be kept constant by changing the preheating period depending on the conduction start phase of the electrodes. In this embodiment, the trigger circuit 19 of the preheating control circuit 17 shown in FIG. The operation should be performed so that the output voltage becomes low when the input voltage becomes low.

Further, both the preheating start phase and the preheating end phase may be changed depending on the conduction start phase of the light control device fi12.

In the above description, the inverter 6 is a push-pull type transistor inverter equipped with a Takaoka wave choke coil, but other inverters can also be used.

Further, the preheating period is controlled within the period in which DC power is supplied from the light control device 2 to the inverter 6 according to the conduction start phase of the light control device 2, and the preheating electrode 7f1°7f! Although the preheating control circuit 17 and the preheating circuit 23 are shown in FIGS. 3 and 5 as means for keeping the temperature constant, the present invention is not limited to the above embodiments as long as the means can realize the purpose. .

Further, in the above embodiment, the case where one discharge lamp is used has been described, but the present invention is not limited to this, and two or more lamps may be lit.

In the embodiment, one dimmer corresponds to one inverter, but in the case of multiple inverters or multiple inverters and a full-wave rectifier, one dimmer or full-wave rectifier may be used. It may be connected to the device.

As described above, according to the discharge lamp lighting device of the present invention, DC power is applied from the dimmer to the inlet 14 and
The preheating electrode is preheated during a part of the period when the discharge lamp is lit, the preheating period t is controlled according to the conduction start phase of the light control device, and the temperature FrL of the preheating electrode is kept constant by changing the preheating power. Since I decided to set the discharge lamp to discharge during the period when direct current power is not supplied to the inverter? It has the advantage of being able to shut off light and achieve smooth dimming. −

[Brief explanation of the drawing]

1st I! iQ is a circuit diagram of a conventional discharge lamp lighting device, Figures 2(1) to 2(d) are ninth diagrams explaining the operation of the discharge lamp lighting device of No. 1@, and No. 3mg is a circuit diagram of the conventional discharge lamp lighting device. 4(a) to 4(f) are diagrams for explaining the operation of the discharge lamp lighting device of the present invention, and FIG. 5 is a circuit diagram showing an embodiment of the discharge lamp lighting device of the present invention. A circuit diagram showing a specific embodiment of the discharge lamp lighting device, FIG. 6(a)
5(d) is a diagram for explaining the operation of the discharge lamp lighting device of FIG. 5. FIG. 1... AC power supply, 2... Light control device, 5... Full wave rectifier, 6... Inverter, 7... Discharge lamp, 7f1
．． 7f, ... Preheating electrode, 8... Output Lance,
9&, 9b...Switching transistor, 1B...
・DC power supply, 19...Trigger circuit, 20...Voltage detection circuit, 21...Delay circuit, 22...Output circuit, 2
3... Preheating circuit, 24°26... Transistor, 2
5...Oscillation circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno −

Claims (2)

[Claims] (1) An inverter that inputs a pulsating DC voltage obtained by full-wave rectification of the voltage of an AC power supply, a discharge lamp having a preheating electrode that is lit by the output AC voltage of this inverter, and a space between the AC power supply and the inverter. The I! of the discharge lamp is interposed by phase control. a dimmer that performs a Qi source, a preheating circuit that preheats a preheating electrode of the discharge lamp, and a lighting device that controls at least one of a preheating start phase or a preheating end phase of the preheating electrode according to a conduction start phase of the lighting device. A discharge lamp lighting device comprising: a preheating control circuit that causes the preheating circuit to preheat the preheating electrode in a manner that varies during a period in which power is supplied to the inverter. (2) The preheating control fnrm path operates so that the preheating end phase is a phase in which the voltage of the AC power source is approximately Ov, and the preheating start phase is changed.
T! The discharge lamp lighting device according to item 1.