JPS6054199A - Dimmer for 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 (Technical Field of the Invention) The present invention relates to a dimmer for a discharge lamp that controls the brightness of a discharge lamp and saves power consumption.

(2) Prior Art and Problems Conventionally, an AC thyristor, such as a trybook, is used as an element for switching on and off the power of a dimmer for a discharge lamp, and a system is often used to perform full phase angle control and dimming. FIG. 1 shows a conventional circuit in comparison with the present invention, with the zero-cross pulse circuit 11 enclosed in a double frame removed.

A control circuit of the trybook B is provided between the power source 1 and the discharge lamp fixture 7. In other words, diodes 51°52 connected in the butt direction and diodes 5g+5 connected in opposite directions.
4'f, installed in parallel, diodes 5j+52 and 55+"
A triac 6 is inserted between each connection point of 4, and a resistor 8 and a capacitor 90 shunt are provided on the outside. The power supply waveform is input from the waveform detection circuit 2 installed in parallel to the power supply into the phase control circuit 3, and a predetermined phase is set, and gate turn-off (GTO) is performed.
Via the drive circuit 4, the gate of the triac 6 is cut off for a certain period of time in each half cycle of the waveform to perform dimming control.

As shown in Fig. 2, the discharge lamp fixture 7 includes a discharge lamp 7-2 and a starting lamp 7-3 installed in parallel on the secondary side of a single-winding transformer 7-1, and a phase advancing lamp on the primary side. A capacitor 7-4 is connected.

FIGS. 3(cL) to (1) are explanatory diagrams of the operation of the conventional example shown in FIG. 1. The figure (α) μ shows the voltage waveform during conventional phase control. That is, after the triac 6 is disconnected for a time T1 from OV, conduction starts at the set phase.

However, as shown in the current value flowing through the discharge lamp fixture 8 in Figure (b), an inrush current occurred when the gate of the triac 6 was turned on, damaging the triac 6 and causing an abnormality in the noise absorption coil (not shown). (generated a high-pitched sound). Figure (6) shows the case where the phase advance capacitor 7-4-i is removed, and although there is no problem with the waveform, the power factor cannot be improved.

(3) Purpose of the Invention The purpose of the present invention is to provide a new invention which improves the above-mentioned drawbacks, and to provide an effective and trouble-free dimming method for discharge lamps with capacitive input impedance that can improve the power factor. It is an object of the present invention to provide a discharge lamp dimmer that can be used.

(4) Structure of the Invention In order to achieve the above object, the discharge lamp dimmer of the present invention is a discharge lamp with capacitive input impedance that dims using an element that controls the setting phase of each half cycle of an AC power supply. The device is characterized in that it is provided with means for detecting a zero-crossing point of the AC power source, and is controlled so that the element is turned on at the zero-crossing point to start discharging and cut off at a set phase point.

(5) Embodiment of the invention Fig. 1 fJ, til! As described above, this is an example circuit of the present invention compared with the conventional example.

In the figure, the difference from the conventional example is that a zero-cross pulse circuit 11 surrounded by a double frame is provided. In other words, the waveform from the waveform detection circuit 2 is guided to the zero-crossing circuit 11, which detects the zero-crossing point and outputs a pulse in response to the zero-crossing point. Contrary to FIG. 3 (α), the triac 6t is made conductive after the zero cross point to discharge the discharge lamp, and after the elapse of time T1 corresponding to a predetermined phase, the gate of the triac 6 is turned off, thereby causing discharge. It controls the dimming of the electric light fixture 7.

FIGS. 4(α) and 4(b) are operational waveform diagrams of the embodiment of the present invention. The figure (6) shows the voltage waveform applied to the discharge lamp fixture 7 during dimming, and the figure (6) shows the current waveform. In other words, when the AC power waveform reaches zero volts, a pulse is output. The triac is turned on, the discharge lamp starts discharging f, and is turned off after the elapse of time T1.In this case, the relationship between the conduction period and the non-conduction period is opposite to that of the conventional example shown in FIG. 3(cL). With this configuration, no inrush current is generated as shown in the current waveform in FIG. 6(b), so there are no problems such as damage to the trybook or generation of high-pitched noise in the noise absorption coil. The light can be changed freely by arbitrarily setting the discharge time T1.

(6) Detailed Description of the Invention As described above, according to the present invention, the zero-crossing point of the AC power source is detected, and the discharge lamp equipment is energized from this zero-crossing point and disconnected at a set phase. By reversing the relationship between the conduction period and non-conduction period of the conventional triac in this way, no inrush current occurs even when using a discharge lamp device with a capacitive input impedance as described above, so the triac can be damaged. There will be no such trouble, and no abnormal noise will occur in the noise absorbing coil. Therefore, it will be of great help in expanding the field of use of phase advancing discharge lamp equipment.

[Brief explanation of drawings]

Fig. 1 is a configuration explanatory diagram of an embodiment of the present invention shown in comparison with a conventional example, Fig. 2 is a detailed circuit diagram of the main part of Fig. 1, Fig. 3 is an operation waveform diagram of the conventional example, and Fig. 4 1 is an operation waveform diagram of the present invention.
In the figure, 1 is an AC power supply, 2 is a waveform detection circuit, 3 is a phase control circuit, 4 is a GTO drive circuit, and 5. -54 is a diode, 6
is triac, 7 is discharge lamp equipment, 7-1 is transformer%
Y-2n release! 7-5 is a starting pair, 7-4 is a phase advance capacitor v, an au resistor, 9 is a capacitor, and 11 is a zero-cross pulse circuit. Patent applicant Shiratori Seisakusho Co., Ltd. Agent Patent attorney 1) Yoshishige Saka 1 Figure 2 Figure 3 @ Figure 4 Procedural amendment (voluntary) Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case 1988 Patent application No. 162796 2, Title of the invention: Dimmer for discharge lamps 5, Relationship with the case of the person making the amendment Patent applicant 4/Agent 7,77 Amended specification Title of the invention: Dimmer for discharge lamps 2. Claims: In a discharge lamp device with capacitive input impedance [, AC! , a means is provided for detecting the zero-crossing point of the AC power supply using an element whose conduction and disconnection can be controlled according to a set phase for each half cycle of the source, and the element is made conductive at the zero-crossing point to start discharging. A dimmer for a discharge lamp, characterized in that it is controlled to cut off at a set phase point. 3. Detailed Description of the Invention (1) Technical Field of the Invention The present invention relates to a dimmer for a discharge lamp that controls the brightness of a discharge lamp fixture and saves power consumption. (2) Prior Art and Problems Conventionally, it has been common to perform phase control and dimming using a Zyristor or a triac as an element for switching on and off the power of a dimmer for a discharge lamp. FIG. 1 shows a conventional circuit, in which a triac 3 is inserted between an AC power supply 1 and a discharge lamp fixture 4 via a noise absorbing coil 2, and a phase control circuit 5 connected in parallel to the power supply 1 is used to to control dimming. As shown in Fig. 3, the discharge lamp fixture 4 is provided with a discharge lamp 4-2 and a starting lamp 4-3 in parallel on the secondary side of a single-winding transformer 4-1, and a phase advancing lamp on the primary side. In some cases, a capacitor 4-4 is connected to provide capacitive input impedance to improve the power factor. FIGS. 2(cL) to 2(c) are operational waveform diagrams of the conventional example. Figure (α) shows the voltage waveform when a resistive load such as an incandescent lamp is controlled using the conventional phase control method. That is, O.V.
The triac 6 in FIG. 1 is non-conducting for 71 hours from then on, and starts conducting at the set phase after time T1. However, the current waveform flowing through the discharge lamp fixture 4 with capacitive input impedance as shown in Fig. 3 is similar to that shown in Fig. 2(b), where an excessive inrush current occurs immediately after conduction and the triac 3 is damaged. , the noise absorbing coil 2 generates an abnormally high sound. FIG. 4(c) shows a case where the phase advance capacitor 4-4 used in a discharge lamp with capacitive input impedance is removed, but although this poses no problem on the waveform, the power factor cannot be improved. (3) Purpose of the invention Purpose of the present invention 1. This is a new invention that improves the above-mentioned drawbacks. 1. To perform effective and trouble-free dimming of a capacitive input impedance discharge lamp fixture with improved power factor. An object of the present invention is to provide a discharge lamp dimmer that can perform the following functions. (4) Configuration of the emitting device In order to achieve the above object, the discharge lamp dimmer of the present invention uses an element that is controlled by the set phase of each half cycle of the AC power supply in a discharge lamp apparatus with a capacitive input impedance. and providing means for detecting a zero-crossing point of the AC power supply,
The device is characterized in that the light is dimmed by controlling the device to conduct at the zero cross point to start discharging and cut off at the set phase point. (5) Embodiment of the invention Figure 4 shows an example circuit of the invention, Figure 5 (→, (
b) is an operation explanatory diagram. In contrast to the conventional example shown in FIG. 1, a cross pulse circuit 17 surrounded by a double frame is provided, and
The feature is that the triac No. 3 is replaced with a gate turn-off thyristor 13. That is, the waveform from the waveform detection circuit 11 is guided to the zero cross pulse circuit 13, a zero cross point is detected, and a zero cross position pulse corresponding to this is input to the gate drive circuit 18 to make the gate turn-off thyristor 13 conductive. In other words, the conventional example shown in Fig. 2 (α
Contrary to the disconnection from 0 to T1 time in Figure 5 (→), conduction is made from Ov to T1 time in Figure 5 (→). Phase control is performed, a corresponding pulse is output, this phase control pulse is input to the gate drive circuit 18, and the gate turn-off thyristor 16 is disconnected from OV by T1 time.Contrary to the conventional example, after the zeroth Subarth point The gate turn-or-thyristor 13 is made conductive to discharge the discharge lamp A4, and after the elapse of time T1 corresponding to a predetermined phase, the gate-turn-or-thyristor 16 is disconnected, thereby controlling the dimming space IJ of the discharge lamp fixture 4. In the operating waveform diagram of the conventional example shown in FIG. As shown in the current value flowing through the discharge lamp fixture 4 in )), an inrush current was generated when the triac 6 was turned on, damaging the triac 6 and causing the noise absorption coil 2 to generate an abnormally high sound. . In the operating waveform of the present invention shown in FIG. 5, the relationship between the conduction period and the non-conduction period is opposite to that of the conventional example. This configuration does not generate an inrush current as shown in the current waveform () in the same figure, so the gate turn-off thyristor 1
This eliminates the problems caused by damage to the noise absorbing coil 2 and the generation of high-pitched sounds in the noise absorbing coil 2. Light control can be freely changed by arbitrarily setting the discharge time T1. (6) Detailed Description of the Invention As described above, according to the present invention, the zero-crossing point of the AC power supply is detected, and the discharge lamp equipment is energized from this zero-crossing point and disconnected at a set phase. By reversing the relationship between the conduction period and the non-conduction period of the conventional trybook, no inrush current occurs even when applied to the discharge lamp device with the capacitive input impedance mentioned above. There will be no trouble that could damage the turn-off thyristor, and no abnormal noise will occur in the noise absorbing coil. Therefore, it has become possible to dim a discharge lamp fixture with a capacitive input impedance, which was conventionally not dimmable. 4. Brief description of the drawings Figure 1 is a configuration diagram of a conventional example, Figure 2 is an operating waveform diagram of a conventional example, Figure 3 is a circuit example of a discharge lamp fixture with capacitive input impedance, and Figure 4 is an example of implementation. An explanatory diagram of the configuration of an example, FIG. 5 is an operation waveform diagram of the present invention, in which 1 is an AC power supply, 4 is a discharge lamp equipment, 4-1 is a transformer, 4-2 is a discharge lamp, and 4-3 is Starting light, 4-4 is a phase advance capacitor, 11 is a waveform detection circuit, 121 to 124 are diodes, 13 is a gate turn-off thyristor, 14 is a resistor, 15 is a capacitor, 16 is a phase control circuit, 17 is a zero-cross pulse circuit, 18 indicates a gate drive circuit. Figure 1, M2, Figure 3, Figure 4, Figure 5 Procedures Amendment (self-motivated) Year 1982/Yen Day 2 Title of invention Discharge lamp dimmer 6 Person making the amendment Figure 4 Procedural amendment (voluntary) May 25, 1980 Patent application No. 162796 2, Title of invention Discharge lamp dimmer 3, Relationship with the person making the amendment Case Patent applicant (1) 1982 The date of May 8, 2017 is No. 4, page 4 of the amended specification.
Row ~ 7th row 1 gate turn off Sai Risk 1'5...
・Lead to the Xerox pulse circuit 15,” is changed to [-
It is characterized by replacing the turn-off thyristor 13 with a turn-off thyristor. That is, the waveform from the waveform detection circuit 11 is guided to the zero-cross pulse circuit 17 and corrected as follows.

Claims (1)

[Claims] In a discharge lamp apparatus having a capacitive input impedance that dims using an element controlled by a set phase of each half cycle of an AC power supply, means for detecting a zero-crossing point of the AC power supply is provided, and at the zero-crossing point, the A dimmer for a discharge lamp, characterized in that the dimmer is controlled so that an element becomes conductive to start discharging and is cut off at a set phase point.