JP2963467B2 - Discharge lamp lighting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device connected to a phase control dimmer to control dimming of a discharge lamp.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. 63-81795, a conventional discharge lamp lighting device slices an output voltage waveform of a dimmer at a predetermined voltage level to thereby control the dimmer. The flow angle is detected, and the dimming degree is changed by controlling the opening / closing operation of the switching element in the discharge lamp lighting circuit operating at the high frequency voltage based on the detected flow angle.

[Problems to be solved by the invention]

However, a sufficient starting voltage is required to light the discharge lamp, and when the flow angle of the phase control dimmer is expanded to a certain degree or more, the starting operation is performed to ensure that the discharge lamp is started. Can be started. However, when the discharge lamp shifts from a state in which the discharge lamp is not lit to a state in which the discharge lamp is started, a load fluctuation occurs, and the phase control dimmer receives the influence thereof, and the distribution angle becomes narrow, and the light is turned off again. There was a defect that would. Furthermore, when the discharge lamp is not yet lit, the output waveform of the phase control dimmer is unstable, so that the lighting operation may be started with an incorrect waveform and the start may fail. The above prior art does not consider these points.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above two disadvantages and to obtain a discharge lamp lighting device that reliably lights even when connected to a phase control dimmer.

[Means for solving the problem]

The above object is achieved by setting the flow angle of the phase control dimmer for starting the starting operation to A, the flow angle of the phase control dimmer for turning off the discharge lamp after lighting to B, and the relationship of A> B. Is done.

In addition, the detection of the flow angle when the discharge lamp is not yet lit is performed by connecting a series circuit of a downhole and a switch element to the secondary side of the rectifier circuit, and periodically opening and closing the switch element. It is configured to determine whether to start the discharge lamp based on the flow angle during the period when the switch element is closed. Furthermore, the period during which the switch element is open is set to 20 ms.
As described above, a stable output waveform of the phase control dimmer is obtained.

[Action]

When the discharge lamp is not lit, the power supply smoothing capacitance of the lighting circuit is simply connected to the dimmer and becomes a capacitive load, so that the output voltage waveform of the phase control dimmer becomes unstable.
Therefore, if an attempt is made to turn on the discharge lamp when the detected distribution angle exceeds a certain value, an erroneous waveform is detected, and the discharge lamp cannot be turned on reliably.
Therefore, a reversible load is connected to the power supply, and the power is periodically interrupted to suppress the power loss of the reluctance load. By detecting the flow angle during the period when the current flows through the anti-recessive load, that is, during the period when the output waveform of the phase control dimmer is stable, reliable startability can be obtained. In addition, the period during which the current flows through the anti-recessive load is at least
In other words, a more stable waveform can be obtained by setting two cycles of the waveform after full-wave rectification of the commercial power supply.

4 When the discharge lamp is turned on, the load viewed from the dimmer fluctuates, and the distribution angle becomes narrow. Therefore, it is necessary to set the flow angle for turning off the discharge lamp to a value smaller than the flow angle at that time.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. First
FIG. 2 is a circuit diagram showing one embodiment of a discharge lamp lighting device according to the present invention, FIG. 2 is a diagram showing voltage waveforms in the above embodiment, FIG. 3 is a diagram showing a relationship between opening and closing of a switch element and a flow angle;
FIG. 4 is a circuit diagram showing another embodiment of the present invention. First
In the figure, 1 is an AC power supply, 2 is a phase control dimmer, 3 is a full-wave rectifier, 4 is a partial smoothing circuit, 5 and 6 are flow angle detection resistors, 7 is a flow angle detection circuit, 8 is a control circuit, 9 Is a load shaft, 10 and 11 are switch elements, 12 is a diode, 13
Is a resonance capacitor, 14 is a current limiting choke coil, 15 is a discharge lamp having filaments 16 and 17, 18 is a preheating capacitor, and 19 is a preheating choke coil.

An AC voltage whose flow angle is controlled is input from the AC power supply 1 to the full-wave rectifier 3 via the phase control dimmer 2. A voltage waveform obtained by dividing the output voltage of the full-wave rectifier 3 by the flow angle detection resistors 5 and 6 is shown in FIG.
It is. The waveform 22 is obtained by slicing the waveform 20 at a certain constant voltage level as indicated by a dashed line 21.
The above function is performed by the flow angle detection circuit 7 shown in FIG. When the flow angle of the phase control dimmer 2 obtained by the flow angle detection circuit 7 is larger than about 90 °, the control circuit 8 controls the opening and closing of the switch element 11, and the resonance capacitor 13 and the current limiting choke coil 14. Resonance occurs between the preheating capacitor 18 and the preheating choke coil 19, and the filaments 16 and 17 of the discharge lamp 15 are preheated. Further, a high voltage is generated at both ends of the parallel circuit of the preheating capacitor 18 and the preheating choke coil 19, and the discharge lamp 15 is turned on. In addition, a current is supplied to the load shaft 9 while periodically controlling the opening and closing of the switch element 10 to stabilize the waveform of the phase control dimmer 2.
In FIG. 3, a waveform 23 indicates an output waveform of the flow angle detection circuit 7, and a waveform 24 indicates a drive waveform of the switch element 10. The switch element 10 is closed during a high voltage period. As shown in FIG. 3, the switch element 10 is closed and the second waveform 25
Shows a stable flow angle, but the waveform during the period in which the switch element 10 is open is irregular, and particularly when the flow angle is erroneously detected as a waveform 26, it is sufficient to start the discharge lamp 15. No voltage is obtained and startup fails. Therefore, take a time of 20 ms or more so that at least two waveforms fall within the period in which the switch element 10 is closed, and fetch the data of the flow angle in synchronization with the period in which the switch element 10 is closed. Thereby, the discharge lamp 15 can be started stably.

However, when the discharge lamp 15 is turned on, the load state viewed from the phase control dimmer 2 changes and affects the flow angle, so that the flow angle becomes narrower than before lighting. Therefore, by stopping the drive of the switch element 11, by setting the flow angle at which the discharge lamp 15 is turned off to be smaller than the flow angle at the time of starting the discharge lamp 15, even when the flow angle becomes narrow when turned on, It can be stably turned on without being turned off again.

While the resonance circuit is used in the lighting circuit of the embodiment shown in FIG. 1, the other embodiment shown in FIG. 4 is realized by a self-excited two-piece push-pull circuit. Further, it can be used for various circuits such as a half bridge circuit and a full bridge circuit. In FIG. 4, 31 is a switch element, 30 is a downhole, 32
Is a current limiting choke coil, 33 is a transformer, 34 is a resonance capacitor, 35 and 36 are transistors, and the same reference numerals as those shown in FIG. 1 denote the same or equivalent parts. In another embodiment shown in FIG.
When the angle reaches 90 ° or more, the base current is supplied to the transistors 35 and 36 by closing the switch element 31 to start oscillation and turn on the discharge lamp 15. As described above, the present invention can be applied not only to a separately excited circuit but also to a self-excited circuit.

〔The invention's effect〕

As described above, in the discharge lamp lighting device according to the present invention, the input terminal is connected to the AC power supply via the phase control dimmer, and the input terminal, the rectifier circuit, the smoothing circuit, and the discharge lamp lighting device operating at high frequency. A discharge lamp connected to an output of the discharge lamp lighting circuit, and a circuit for detecting a flow angle of a phase control dimmer connected between secondary terminals of the rectifier circuit; When the discharge angle becomes not less than the predetermined value A, the discharge lamp is turned on when the flow angle is equal to or more than the predetermined value A. When the discharge angle is not more than the predetermined value B when the discharge lamp is turned on, the discharge lamp is turned off. , A and B satisfy A> B, so that it is possible to obtain a discharge lamp lighting device capable of obtaining stable lighting even when connected to a phase control dimmer.

[Brief description of the drawings]

1 is a circuit diagram showing an embodiment of a discharge lamp lighting device according to the present invention, FIG. 2 is a diagram showing a voltage waveform in the above embodiment, and FIG. 3 is a diagram showing a relationship between opening and closing of a switch element and a flow angle. FIG. 4 is a circuit diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... AC power supply 2 ... Phase control dimmer 3 ... Rectifier circuit 4 ... Smoothing circuit 7 ... Flow angle detection circuit 9 ... Temperature 10 ... Switching element 15 ... Discharge lamp

────────────────────────────────────────────────── (5) References JP-A-63-81795 (JP, A) JP-A-3-101096 (JP, A) JP-A-3-233895 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) H05B 41/38-41/42

Claims (3)

(57) [Claims] An input terminal is connected to an AC power supply via a phase control dimmer, said input terminal, a rectifier circuit, a smoothing circuit, a discharge lamp lighting circuit operating at a high frequency, and said discharge lamp lighting circuit. And a discharge lamp connected to the output of the rectifier circuit, a circuit for detecting the flow angle of the phase control dimmer is connected between the secondary terminals of the rectifier circuit, and when the discharge lamp is not lit, the flow angle is When the discharge lamp is turned on when the discharge angle becomes equal to or more than a predetermined value A, the discharge lamp is turned off when the distribution angle becomes equal to or less than a predetermined value B when the discharge lamp is turned on. Is a discharge lamp lighting device in which A> B. 2. The flow angle detection circuit according to claim 1, wherein a series circuit of a shaft and a switch element is connected in parallel, and the switch element periodically opens and closes. 2. The discharge lamp lighting device according to claim 1, wherein whether to turn on said discharge lamp is determined based on a detected value of the flow angle detected when said lamp is closed. 3. The discharge lamp according to claim 2, wherein the switch element is closed for at least 20 ms in one cycle during the switching operation during the non-lighting state. Lighting device.