JPS5838492A - Device for firing 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 up all of the discharge lamps using high frequency and is capable of dimming. The AC power source is controlled by full phase control, and the output full-wave rectified DC voltage is input to the inverter, and a discharge lamp such as a fluorescent lamp is fully used with the inverter to generate 2 to 3 KI-■z.
Attempts have been made in the past to turn on the light at the above-mentioned high frequency and to perform full dimming by changing the phase angle, since this provides good dimming with less flicker. As such a device, the device shown in FIG. 1 has been known. In FIG. 1, ■ is an AC power supply, 2 is a dimming device that controls the entire voltage phase of the AC power source 1, and is connected to a bidirectional Zyrister 3 and a control device 4 that controls the entire conduction start phase of this. It has become. Reference numeral 6 denotes an inverter, which here is constituted by a push-pull type transistor inverter having a resonant circuit, and its input is the full DC voltage rectified by the output full-wave rectifier 5 of the dimming bag ff2. 7 is a discharge lamp, such as a fluorescent lamp, having a preheating electrode 7f. The inverter 6 has an output winding of 8s and a collector winding of 8cl.
, 8cz, pace feedback winding 8h, filament winding 8f
i, an output transformer 8 consisting of a leakage transformer, switching transistors 9a and 9b, a high frequency choke coil xO, and a JNM capacitor 11. bias resistors 12a, 12b, etc.). That is, the midpoint of the collector windings 8c1 + 8c2 is connected to the positive output end of the full-wave rectifier 5. This output end is connected to each pace of switching transistors 9a and 9b via pace bias resistors 12a and 12bt. Switching transistor 9 a r
The pace 9b is connected across the pace return winding 8b. switching transistor fi 9 a *
Each collector of 9b has collector winding m 8 ct *8c
2 is connected to one end of each. This collector winding 8cl
, 8c2 are connected to both ends of the resonant capacitor 11. Both emitters of the switching transistors 9a and 9b are commonly connected to the negative output terminal of the full-wave rectifier 5 through the high-frequency choke coil IO. Further, both ends of the secondary winding 8B of the output transformer 80 are connected to the discharge lamp 7, and each of the preheating electrodes 7f of the discharge lamp 7 is connected to a filament winding 8f. On the other hand, reference numeral 13 denotes an auxiliary DC power supply, which is composed of an auxiliary winding 8 of an output transformer 8, a rectifier circuit 14, a capacitor 16, and a diode 15. That is, both ends of this auxiliary winding 8 are connected to the input terminal of a rectifier circuit 14, and a capacitor 16 is connected between its positive output terminal and negative output terminal. Further, the positive side output terminal is connected to the positive side output terminal of the full wave rectifier 5 via the diode 15, and the negative side output terminal of the full wave rectifier 5 and the negative side output terminal of the rectifier circuit 14 are connected to the positive side output terminal of the full wave rectifier 5. connected in common. Next, the operation of the discharge lamp lighting device of FIG. 1 configured as above will be explained. When the AC power source 1 is turned on, the bidirectional thyristor 3 changes its conduction start phase to the phase 01, for example, as shown in FIG. DC power is supplied for a period TI. During the period TI, the inverter 6 has a bias resistor 12a. 12b υ pace current is supplied, pace return winding #8b
The well-known self-oscillation occurs due to the above action, and a high frequency iE fE ' is generated in each winding of the output transformer 8, and preheated by the filament winding 8f. ffM7f' (z preheat,
All discharge lamps 7 are lit. Further, the degree of dimming is performed by changing the conduction start phase 01 by the dimming device t2. During the period T+fi, no DC power is supplied to the inverter 6 from the dimmer 2, so during the period T□ when the dimmer 2 is supplying DC fit power, the voltage to the auxiliary winding 8 is fully rectified. A capacitor 16' is charged via a circuit 14' to a voltage V at its terminals. p
It is designed to be supplied to the input of the inverter 6 during the T2 period, and the input voltage to the inverter 60 is as shown in Figure 2 (A).
It becomes as shown in . The period T2 during which the voltage of this capacitor 16 is applied to the inverter 6 is due to Since the terminal voltage Vop of the capacitor 16 is set to 5 so that the Ij lamp 7 is turned off, the discharge lamp 7 is turned off, the preheating electrode 7f of the discharge lamp 7 is preheated by the filament winding 8f, and the preheating voltage is As shown in Figure 2). Note that FIG. 2 ←) shows the entire discharge current of the discharge lamp 7. As described above, it is possible to properly set the terminal voltage VOP and capacitance fat of the capacitor 16, and also to preheat the preheating electrode 7f during the pause period of the discharge flow, so that the dimming of the discharge lamp 7 can be adjusted. This is intended to achieve smooth heating, to completely suppress wear of the preheating electrode 7f, and to extend the life of the discharge lamp 7. However, in such a conventional discharge lamp lighting device, the DC voltage from the dimmer η2 becomes low and the inverter 60
When the input voltage reaches the voltage of the capacitor 16, the γ of the capacitor 16 increases due to fluctuations in the AC power supply l.

If the pressure is high, the discharge of the discharge lamp 7 tends to continue without stopping. If the discharge continues, not only will dimming not be performed smoothly, but the charge in the capacitor 16 will be rapidly discharged, and the voltage at its terminals will suddenly drop. If the voltage of the capacitor 16 is set low to prevent the discharge from continuing, the input voltage of the inverter 60 will drop, and the voltage of the filament winding 8f will drop, causing the preheating electrode 7f to drop. It becomes impossible to preheat the equipment sufficiently. Furthermore, since the capacitor 16 requires all 111-solution capacitors of large IJM, the lighting device tends to be large in size, and the life of the electrolytic capacitor tends to be shortened. The present invention completely eliminates the above-mentioned conventional drawbacks, and provides a complete discharge lamp lighting device that can perform smooth dimming by sufficiently preheating the inverter during the period when DC power is supplied from the dimming device. The entire purpose is to DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a discharge lamp lighting device of the present invention will be described based on all the drawings. FIG. 3 is a circuit diagram showing the entire configuration of one embodiment. In this FIG. 3 VC, when explaining the configuration,
Components that are the same as those in FIG. 1 will be given the same reference numerals and their explanations will be omitted, and portions that are different from FIG. 1 will be described with emphasis on all parts. As is clear from the comparison between this Figure 3 and Figure 1,
The auxiliary DC power supply 13 in FIG. 1 is removed, and the parts indicated by reference numerals 17 onwards are newly added to the circuit in FIG. 1. In other words, 17 is a preheating control circuit. DC power supply 18 obtained by fully step-down rectifying and smoothing the output of 2, and resistor 19
a-19d, the trigger circuit 19 is connected to the transistor 19e, and the output of the trigger circuit 19 changes from "L" to r i
The delay circuit 20 starts a delay operation when the value changes to -1, J, and is composed of a monostable multivibrator or the like having a predetermined delay time. That is, the resistors 19a and 19c are connected in series between the positive output terminal and the negative output terminal of the full-wave rectifier 5, and the connection point between the resistors 19a and 19c is connected to the transistor 19e via the resistor 19bk. Connected to the pace of. The collector of the transistor 19e is connected to the positive terminal of the DC power supply 18 through the resistor 19d, and is also configured to output a signal to the monostable multi-pie break 20. The emitter of transistor 19e is connected to the negative electrode of DC power supply 18. A voltage from a DC power supply 18 is applied to the monostable multivibrator 20 . This monostable multi-pie break 20
The output of the transistor 220 of the preheating circuit 21 is supplied to the transistor 220 of the preheating circuit 21. It is comprised of a transistor 22 controlled by the output of the preheating control circuit 17, a rectifier circuit 23, and a preheating transformer 24. In this preheating circuit 21, the emitter of the transistor 22 is connected to the negative electrode of the DC power supply 18 and the negative output terminal of the rectifier circuit 23. The collector of the transistor 22 is connected to the positive output terminal of the rectifier circuit 23. One input terminal of the rectifier circuit 23 is connected to the primary winding 2 of the preheating transformer 24.
It is connected to one end of 4c. This first volume tW 24
The other end of c is connected to one end of the collector winding Rr4 of the output quadrangle 8. The other input end of the rectifier circuit 23 is connected to one end of the collector winding 8cl. Preheating winding 24
f are connected in series with the filament winding 8f of the output transformer 8, respectively. Next, the operation of the discharge lamp lighting device of the present invention configured as above will be explained. Figure 4 (7) - Figure 4)
4 (7) is the input voltage of the inverter 6, and FIG. 4 (a) is the voltage of the collector winding 8clr 8c2 of the output transformer 8.
is the voltage of the preheating electrode 7f of the discharge lamp 7. Now, when AC power l is applied, the bidirectional thyristor 3
The conduction start phase is set to the fourth phase by the signal from the control device f4.
When θ1 is set as shown in FIG. 7, time pulsating DC power TI is supplied to the inverter 6. During this period, a pace current is supplied to the switching transistors 9a * 9b through the bias resistors 12a and 12bi, and due to the action of the pace feedback winding 8b, etc., the self-oscillation is fully performed and the output transformer 8 is A high frequency voltage is generated in each winding, and all discharge lamps 7 are lit. In addition, the degree of dimming is determined by the light control device 2 at a conduction start phase of 0.
This is done by changing 1. At this time, the voltage of the filament winding 8f is applied to the preheating electrode 7f via the preheating winding 24f of the preheating transformer 24, thereby preheating the preheating electrode 7f. On the other hand, the preheating control circuit] 7 has a tco-1rtt current power supply 18 and an inverter with 60 manpower? The IU pressure is no longer applied to the IJ jf circuit I9. l・Rep circuit 19L1 human power box 111
Since Ek is inverted, the output of the trigger circuit 19 has a phase θ. rHJ from θ1 to θ1, T1 period rL from θ1 to θ0
J, and the change in output is the phase θ. "T1" from rLJ
becomes. The output of the trigger circuit 19 is applied to the delay circuit 20, and the output changes from "L" to "T1" at θ. The delay operation fully starts at the phase where the voltage of the AC power supply l is #'J OV I/C'l. Delay j41=The delay time of the circuit 20 is set to T2 shown in FIG. After the period of 1゛2 has elapsed, the delay operation is completed, and the delay circuit 2 is activated at the phase of θ2.
The output of 0 becomes r HJ, then the tree) f becomes the opening force 11
The output continues for a period of T until the output is ``1''. The period t when the output of the delay circuit 20 is "1", the preheating circuit 2
1 transistor 22 conducts, and the voltage of the collector winding 8c of the output transformer 8 passes through the rectifier circuit 23 to the primary winding +li! of the preheating transformer 24. 24c. At this time, a voltage in phase with the filament winding 8f of the output transformer 8 is generated in the preheating winding 24f of the preheating transformer 24, and since the preheating winding M24f and the filament winding 8f are connected in series, the preheating γ1 pole The voltage at 1 of 7f is the sum of the voltages of the preheating winding 18f and the filament winding 8f. In this way, the preheating electrode 7fiJ is
- At the same time when a DC voltage is applied to the inverter 6, the filament winding 1s8f of the output transformer 8 is preheated for a period of T by the voltage Vt, and then the period T4 until the AC power source 1 becomes almost Ov is the filament winding of the output transformer 8. line 8f
voltage Vl of the preheating winding 24 of the preheating transformer 24
: Preheated with voltage of sum of IE V2 and preheated II", pole 7
The hot stones of f are expensive. Therefore, the DC voltage applied to the inverter 6 becomes approximately 0. Immediately after the discharge lamp 7 goes out at the phase where the preheating electrode 7f stops preheating, the preheating electrode 4 & 7 f i:
The temperature has reached a sufficiently high temperature, and the suspension period of the discharge current has ended.
DC voltage is applied to the inverter 6 again, and the preheating electrode 7fi discharge lamp 7
The temperature can be set such that the temperature starts to release easily. In addition, since the filament winding 8f completely starts preheating at the same time as the DC voltage is applied to the inverter 6, the preheating electrode 7
The consumption of f can be completely suppressed, and the discharge lamp 7 can be dimmed smoothly. In the above embodiment, the case where 1 + operation start phase of the preheating circuit 2] is constant regardless of the conduction start phase of the dimmer 2, and the operation end phase is a phase where the total current fJJfi 1 + α is OV. However, the start and end phases of the operation of the preheating circuit 21 are determined by direct current M flowing through the inverter 6. It goes without saying that the change may be made at any time within the period during which the pressure is applied, or may be changed in accordance with the conduction start phase of the light control device 2; The gold is constant, and the ending phase is set when the AC power supply l is almost 0.
When the phase is changed to (2), the temperature of the preheating electrode 7f can be easily raised when the discharge lamp 7 starts discharging again after the end of the rest period, and the range of dimming can be widened. 'Furthermore, although the case where the inverter 6 is a Gutszol-type transistor inverter equipped with a high-frequency choke coil IO has been described, it is of course applicable to other inverters. As a method of increasing the preheating voltage during a part of the period, the preheating control circuit 17 and the preheating circuit 21 shown in the embodiment shown in FIG. Not done. Furthermore, the discharge lamp 7 can be used not only when lighting one lamp, but also when lighting two lamps.
All lights may be turned on. In addition, in the actual M+i example above, one dimmer has an imper of 1
Although 7 correspond to each other, it goes without saying that a plurality of inverters or inverters and the gold wave rectifier 5 may be connected to one dimmer or full wave rectifier 5. As described above, according to the discharge lamp lighting device of the present invention, the DC voltage is applied from the dimmer to the inverter.
)], the preheating electrode of the discharge lamp is fully preheated, and the preheating voltage is increased during a part of that period, so the pause period of the discharge 'rK 81''J ends and discharge 1 starts again. Since the temperature of the preheating electrode can be raised when attempting to perform the heating, the wear of the preheating 'rh-electrode can be suppressed.
It has the advantage of allowing smooth dimming.

[Brief explanation of the drawing]

Figure 1 shows a conventional discharge lamp unit (1.7, 41/(circuit diagram showing the construction, Figures 2(a) to 2(f)).
, respectively, and FIG. 1 is a diagram for explaining the operation of a conventional discharge lamp lighting device, and FIG.
i! Complete circuit diagram of Example i, Figures 4 (7) to 4
Figure 1) shows glue 111 of the discharge lamp lighting device of the present invention.
This is a diagram for illustration purposes only. 1...AC power supply, 2...Dimmer, 5...Full wave rectifier, 6...Inverter, 7...'fti: lamp, 8...Output transformer, 9a,' ) b...Switch-gong transistor, 17... Preheating control circuit, 18...
・DC 'flt'. Source, 19... Tori is the circuit, 20...
・Monostable multipipe L/-ta, 19e. 22...
・1.Transistor, 2l...preheating circuit, 23...rectifier circuit, 24...preheating lance. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shinichi 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. There is a dimmer which performs phase control to fully dim the discharge lamp; a preheating circuit which fully preheats the preheating electrodes of the discharge lamp; A discharge lamp lighting device comprising: a preheating control circuit that fully preheats the preheating electrodes of the electric lamp and operates the preheating circuit so as to increase the preheating voltage during a part of the preheating period. (2) In the preheating control circuit, the entire starting phase of the period in which the preheating voltage is increased is approximately constant, and the ending phase is AC ilfm and tl is O.
The discharge lamp A+" phantom device according to claim 1, characterized in that the phase is set to be V.