JPS58169898A - 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 device that uses an inverter to convert power from a DC power source into high frequency power and applies it to a discharge lamp such as a fluorescent lamp to light it.

The electric power from the DC power source is converted to a high frequency of several KHz or higher using an inverter to light a fluorescent discharge lamp, avoiding a cold start, and lighting after the electrodes have been sufficiently preheated to prevent wear and tear on the electrodes. The inventors had previously proposed a device as shown in FIG. 1 as a lighting device for suppressing this.

In Figure 1, (1) is a commercial frequency AC power supply.

(2) is a full-wave rectifier, and (3) is an inverter, which here consists of a self-excited transistor inverter equipped with an output transformer (61).(4) C) This inverter (
3) is a control device that controls the operation. (5) is a discharge lamp, and (5A) and (5B) are electrodes.

In addition, the inverter (3) has a collector winding (6c),
Base return winding (6B), filament winding II! (
6F), a secondary winding (6th), and an output transformer (61) consisting of a leakage transformer with each winding (61), between the midpoint of the collector winding (6C) and the output side of the full-wave rectifier (2). Connected inductance + 71. Transistor (8
), (8B), the above transistors (8A), (8B
) base resistance (9A), (9B), -y rector winding @ (6c) and capacitor Ql connected in parallel.
It is composed of.

The control device (4) also includes a transformer 0.0 connected to the AC power source il+. A full-wave rectifier +141 that rectifies the output of this transformer 0, a resistor fi9 and a capacitor aυ connected to both output ends of this full-wave rectifier I, and a trigger whose one terminal is connected to the connection point of this resistor αS and capacitor ae. element (17+), a trigger circuit aυ consisting of a diode 08 whose anode is connected to the other terminal of this trigger element aη, whose anode is connected to the emitter of the transistor (8m), and whose cathode is connected to the negative current of the full-wave rectifier a4. It consists of a thyristor α9 as a switching element whose gate is connected to the cathode of this diode, and a timer device (1), and the output signal of this control device (4) is connected to the resistor (9).
A).

(9B), the transistors (8A) and (8B
) is input to the base of

Furthermore, the timer device ■ consists of a series circuit of a diode 3υ and an electrolytic capacitor @ connected to the output line of the full-wave rectifier I, and a resistor (c) and a capacitor (2) connected in parallel with the electrolytic capacitor (2). ), the connection point of this capacitor @ and resistor @, and the above thyristor (
Zener diode (c) connected between +9 gates
It consists of a series circuit of a diode (2) and a diode (2).

Next, detailed operation will be explained. When AC power +11 is supplied, a voltage as shown in FIG. 3(A) is applied to the inverter (3) via the full-wave rectifier (2).

At the same time, a predetermined voltage is generated in the transformer 0 of the control device (4), and the direct all pressure of the pulsating flow, which is also full-wave rectified, is supplied from the full-wave rectifier α. A trigger circuit αυ including a resistor α9, a capacitor αe, and a trigger element aη operates similarly to a well-known phase control pulse generator, and generates a trigger pulse at a predetermined phase every half cycle of the AC power supply 11+. That is, the capacitor α is connected to the capacitor α via the resistor O9.
When e is charged and its carrier voltage rises and reaches the breakover voltage at trigger element a, trigger element a becomes conductive and the charge in capacitor αe is transferred to trigger element αη and the gate of thyristor 0 via the diode or the like. is applied to become the trigger pulse. Such an operation is performed once every half cycle of the AC power supply +11. Here, for example, trigger circuit 0 is
At the phase shown at 01 in Figure 0).

When a trigger pulse is generated, the switch element αl.

(Here it consists of a thyristor.).

Conducts at phase θ, through resistors (9A) and (9B).

Inverter 13+ transistor (8A), (8B
) with one phase of the base current θ. Continue to supply until nearby.

During the period when the conohose current is not supplied, the collector winding (6) of the output transformer (6) is
The DC output of the full-wave rectifier (2) is applied to 6C), and the pace feedback winding of the output transformer (6) @ (ISB)
The Nyori transistors (8A) and (8B) alternately open and close to start one oscillation, and the output voltage (
6) A high frequency AC voltage as shown in FIG. 2(b) is generated in each winding.

At this time, the electrodes (5A) and (5B) of the discharge lamp (5) are connected to the filament winding Iiii! provided in the output transformer (6). (
6F) output voltage. However, the voltage applied from the secondary winding (6S) to both ends of the discharge lamp (5) is.

Since the discharge is insufficient to start discharging the lamp (5), the discharge lamp (5) does not light up yet.

After preheating of these electrodes (5A) and (5B) has started.

After a predetermined period of time has elapsed, the timer device of the control device (4)
The voltage charged to the capacitor @ through the resistor @ exceeds the Zener voltage of the Zener diode (c). For this reason, thyristor a! J is through a diode (E),
Since it receives a continuous trigger signal, the thyristor (19) is conductive during almost the entire period of the AC power supply (1). Therefore, the transistor (8) of the inverter (3)
A) and (8B) also operate correspondingly, and a voltage as shown in FIG. 3e is generated in each winding of the output transformer (6). At this time.

The electrodes (5A) and (5B) of the discharge lamp Ql are already sufficiently preheated, and the discharge lamp (5) is turned on.

In this way, the discharge lamp (5) has electrodes (5M), (5B)
In order to start the discharge when the electrode (
5A) and (5B) had little damage.

However, in such a device, the inverter (3) oscillates during the phase θ1 to 80 shown in FIG. In phase θ1, since oscillation starts suddenly when the voltage value of the AC power source +1+ is high, noise is likely to occur when oscillation starts in each half cycle of the AC gL source (1), especially when the output voltage (6), Choke coil (7).

The noise from condenser 4 was particularly loud.

The present invention aims to eliminate the above-mentioned drawbacks and provide a device that suppresses noise from the lighting device even during the period when the electrodes of the discharge lamp are being preheated.

The details of this invention will be explained below according to Examples.

FIG. 3 is a circuit diagram showing one embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the operation of this invention. In explaining the configuration in FIG. 3, the same or similar parts as in FIG. 1 will be given the same reference numerals and their explanation will be omitted, and the parts different from those in FIG. 1 will be mainly described. As is clear from comparing Figures 1 and 3, the trigger circuit 0u in Figure 1 is removed and a trigger circuit with a new trigger configuration is provided at the same location, and a transistor is used as the switch element a field. It is.

This trigger circuit at+ includes a resistor aS and a capacitor ae connected to both output terminals of a full-wave rectifier I, and a trigger element a1. A thyristor gradient whose gate is connected to the other terminal of the trigger element fin, whose anode is connected to the positive terminal of the full-wave rectifier I via a resistor (to), and whose cathode is connected to the negative terminal of the full-wave rectifier (2).

On the other hand, the anode of the iris resistor is connected to the base of the transistor O1 as a switching element via the resistor (to) and the diode +II, and the collector of the transistor is connected to the emitter of the transistor (8M) and (8B).
The emitter of transistor a9 is connected to the negative terminal of full-wave rectifier +21. Further, the output of the timer device (2) is connected to the base of the transistor (11) via a diode (1).

Next, detailed operation will be explained. First, AC power supply 111
When is supplied, the voltage shown in Fig. 4 (A) is applied to the inverter (3) via the full-wave rectifier (2), as in the conventional device shown in Fig. +41, and at the same time the voltage shown in Fig. 4 (A) is applied to the A predetermined voltage is also generated in Miko, and a full-wave rectified pulsating DC voltage is supplied from the full-wave rectifier (14).
9. The capacitor αG, ) trigger element aη generates a trigger pulse at a predetermined phase every half cycle of the AC power supply il+ by the same operation as the trigger circuit l1121tJυ of the conventional device shown in FIG.

For example, if a trigger pulse is generated at the phase shown in FIG. 4(A), the thyristor (3) becomes conductive at the phase θ, and the voltage of the AC power source (1) becomes 0. Continues to conduct until the phase of . At this time, the voltage applied to the anode of the thyristor (c) is as shown in FIG. 4 (b). The voltage at the anode of this thyristor ■ is applied to the base of the transistor, which is a switch element (1'J), through a resistor (total) and a diode, so that transistor 0 is in phase from θ0 to θ as shown in FIG. , conducts for a period of T, and this T
, the inverter (
3) Supply base current to transistors (8M) and (8B). However, the inverter (3) also operates in accordance with this, and a voltage as shown in FIG. 4 is generated in each winding of the output transformer (6).

At this time, the electrodes (5M) and (5B) of the discharge lamp (5) are preheated by the output voltage of the filament winding (6F) provided on the output side of the output transformer (6). However, since the voltage applied from the secondary winding (6S) to both ends of the discharge lamp (II) is insufficient to start discharging the discharge lamp (5), the discharge lamp (5) does not light up.

When a predetermined period of time has elapsed after the preheating of the electrodes (5A) and (5B) was started, a resistor (ha ) exceeds the Zener voltage of the Zener diode (c).

For this reason, transistor a! Since J receives a continuous base current through the diode (to), it conducts throughout almost the entire period of the AC power supply (1), and the transistors (8B) and (8B) of the inverter +3) ) also operates correspondingly, and a voltage as shown in FIG. 4 (f) is generated in each winding of the output transformer (6). At this time, the electrodes (5M) and (5B) of the discharge lamp (5) are already heated by the middle molecules, and the discharge lamp (5) is lit. In this way, since the inverter (3) starts oscillating when the DC voltage is low during preheating of the electrodes (5A) and (5B), there is no sudden voltage change when the oscillation starts, and noise can be suppressed.

In the embodiment shown in FIG. 113, the resistor a9. Capacitor Jin...
The termination phase of the preheating of the electrodes (5A) and (5B) is determined by the time it takes for the terminal voltage of the capacitor αe to reach the breakover voltage of the trigger element a'rI using the trigger element a1. and period T, but as shown in Figure 6 (0), the instantaneous value of the AC power source il+ is a constant value vc
It is also possible to set the end phase of preheating by detecting that the preheating temperature has reached . In this case, since the preheating end phase θ can be made constant regardless of the frequency of the AC power source (1), the preheating voltage can be made constant regardless of the frequency of the AC power source (1)9. When the voltage of the AC power supply (1) drops, the phase 0. is delayed, so the preheating period T
1 becomes longer, the preheating voltage increases, and the starting of the discharge lamp (5) can be ensured. This embodiment is shown in FIG.

When a predetermined voltage is applied to the transformer (13) of the control device (4), the voltage obtained by dividing the instantaneous value of the pulsating DC voltage by the resistor (1) and 0υ becomes the voltage lower than the Zener voltage of the Zener diode (to). Phases θ0 to 01 shown in Fig. 6 are open because no trigger signal is applied to the thyristor, and the transistor as is a resistor.

(2) A base current is supplied through the diode 11s, making it conductive. When the phase θ is reached, the instantaneous value of the pulsating current voltage becomes higher than the Zener voltage, so the SIRISK (5) becomes conductive when the gate signal is applied and continues to conduct until the first phase θ. The transistor (Ii) is opened from phase θ to θ in response to the operation of the thyristor (5). Therefore, the voltage of the transistor α9 becomes the same as that shown in FIG. 4 (c). θ.From θ,
Up to this point, the transistors (8A) and (8A) of the inverter (3)
B) supplies the base current. In this case as well, the timer device
After a predetermined period of time has elapsed, transistor 0 is turned on continuously, inverter (3) is operated continuously, and discharge lamp (5) is turned on.
The same is true for lighting up.

In the above explanation, the DC voltage that can be supplied to the inverter (3) is a full wave of pulsating current! In the case of IR, GTE0 (gate turn-off thyristor) etc. were used.

Full-wave rectifier I is also used when phase-controlled AC voltage is supplied by a dimmer, etc. that controls the phase from the latter half of the AC power supply (Figure 6 shows the full-wave rectified voltage at 2+).
It is clear that the apparatus of the present invention can be applied when considering the following situations.

Furthermore, if the DC voltage supplied to the inverter 13) is smoothed by connecting a capacitor to the output terminal of the full-wave rectifier (2) as shown in Figure W43, and smoothed to a DC voltage with less ripple, it is also shown in Figure ε). As shown, a similar effect was obtained by setting the oscillation start phase 0o to the phase where the DC voltage is the lowest.

In addition, the dimming device does not only control the phase of the AC power supply (1), but also uses full-wave rectification of the pulsating voltage to supply the voltage to the inverter (3), and the period during which the oscillation operation of the inverter (3) is stopped is controlled by the AC power source (1). Even if there is a dimmer device installed in the latter half of the power supply (1) that changes the oscillation stop period, the discharge lamp (5) is turned on and the discharge lamp (6) generates in each winding. It is clear that the device of the present invention can be applied when considering a situation where the voltage applied is low as shown in Fig. 6e.

In the above description, the case where there is one discharge lamp is shown, but it goes without saying that the invention can be similarly applied to the case where there are two or more lamps.

As described above, according to the device of the present invention, when starting a discharge lamp, the oscillation start phase during preheating of the electrodes and poles and the phase where the voltage value of the DC voltage applied to the inverter is the lowest are set. Noise can be reduced. In addition, since the DC voltage is a pulsating DC voltage and the end phase of the oscillation is set to the first half of the pulsating DC voltage and the voltage value is above a predetermined value, the voltage of the AC power source decreases and preheating occurs. This has the effect of increasing the voltage and ensuring reliable starting.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of a conventional device, FIG. 2 is an explanatory diagram of its operation, FIG. 3 is a circuit diagram showing the configuration of an embodiment of the device according to the present invention, and FIG. FIG. 5 is a main circuit diagram showing the configuration of another embodiment of the present invention, and FIG. 6 is an explanatory diagram of the operation. In the figure, (1) is an AC power supply, (2) is a full-wave rectifier, (3j is an inverter, (4) is a control device, (5) is a discharge lamp, (5m), (5B) is an electrode, ( 6) is the output transformer. (6F) is the filament winding, (111 is the trigger circuit, @ is the resistor, and @ is the Zener diode. The same symbol indicates the corresponding part. Shin Kuzuno - Master of Literature

Claims (1)

[Scope of Claims] +1) An inverter that converts power supplied from a DC power source into high-frequency AC power, a discharge lamp having a preheating electrode that is heated and lit by the output of the inverter, and when starting the discharge lamp, the the output of the inverter for a period longer than the high frequency AC voltage generated by the inverter. and a control device that repeatedly stops the discharge lamp and preheats the electrodes before starting lighting of the discharge lamp, wherein when the discharge lamp is in a preheating state before starting lighting of the discharge lamp, the oscillation start phase of the inverter is set to A discharge lamp lighting device characterized in that the voltage of a DC power supply applied to an inverter is set to the lowest phase. (2) The discharge lamp lighting device according to claim 1, wherein the DC power source is a pulsating DC power obtained by full-wave rectification of a commercial AC power source. (3) The discharge lamp lighting according to claim 2, characterized in that the oscillation period of the inverter is set to the first half phase of the pulsating DC voltage and the voltage value is equal to or less than a predetermined value. Device. (4) The discharge lamp lighting device according to claim 2 or 3, characterized in that a period for stopping the output of the inverter is provided for each half cycle of the commercial AC power supply. (5) Output of the inverter The discharge lamp lighting device according to any one of claims 2 to 4, characterized in that the period for stopping the inverter is provided after a predetermined phase of each half cycle of the commercial AC power supply. (6) Inverter 6. The discharge lamp lighting device according to claim 1, wherein the period during which output is stopped is reduced after a predetermined period of time after power is supplied from the DC power source.