JPS59173998A - Device for dimming 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 dimming device.

In a configuration in which a discharge lamp is turned on by applying an alternating pressure, the phase of the alternating lightning pressure is controlled immediately before dimming is performed.

For example, in Fig. 1, A is the waveform of the power supply voltage and Lfc
In this case, the phase of the voltage applied to the discharge lamp is controlled 1 for each half wave as shown in B, and the wavefront of one voltage waveform is cut 11f for dimming. However, even if it is possible to perform dimming by shortening the wavefront cutting time of a single voltage waveform using such a dimming means, if the wavefront cutting time is shortened, for example, If the maximum amplitude value of the voltage waveform is included and the ff1 head is turned off, the discharge lamp may suddenly go out. Furthermore, if the wave crest is cut in this way, it may become difficult to start the next time it is used.

In order to avoid this inconvenience, one conventional method used a voltage with a sufficiently high wave follo I/' as the voltage applied to the discharge lamp.
I try to do that. With this, even if the force amplitude is lower than the maximum amplitude value, the starting voltage can be higher than the starting voltage of the discharge lamp. Lz
-L In order to generate high voltage like this, it is necessary to step up the power supply voltage, and if a transformer is used as a stabilizer, the secondary voltage of the transformer must be adjusted. The stand must be made much higher than in the case where no light is used, and the capacity of the transformer must be increased, which inevitably leads to an increase in size.

It is an object of the present invention to enable dimming without the need to increase the voltage applied to the discharge lamp too high and without the difficulty of turning off and starting the discharge lamp.

The invention is characterized in that the heavy pressure applied to the discharge lamp is dimmed by cutting both the wave crest and wave tail portions of each half-wave waveform of the voltage, leaving the maximum amplitude portion. do.

As shown in Part 2 A, if ~A is the power supply's voltage waveform, then the voltage applied to the discharge lamp is waveformed at each half wave as j/j-# head portion W as shown in B. When cutting the tail portions W and , the maximum amplitude portion PM should be left intact. When applying phase-controlled heavy pressure to the discharge lamp in this way, there is no need to cut off the pressure.
The wave crest portion W1. It is obvious that the light can be adjusted by appropriately changing the brightness zone of the weight portion W2. However, since the PM residue of the maximum amplitude portion is subtracted, the voltage with the maximum amplitude is normally applied to the IC discharge lamp. However, it is said that the maximum value of the maximum value is the value required for re-igniting the discharge lamp, so it is very likely that the discharge lamp will go out due to dimming, and it will also be difficult to start it. Therefore, dimming is possible without using the heavy pressure applied to the discharge lamp and the high pressure of L''1: wave height as in the past - the difficulty of starting up and going out. Toichi &, R Yonafu.

Referring to FIG. 3, the embodiment of this invention is as follows: -1 is a female N source terminal -211 -t transformer -3 discharge lamp -4 is an impedance element for stabilizing lightning strikes, which means that the impedance of transformer 2 is The alternating current voltage applied to the power supply terminal 1, which may be used for both purposes, is stepped up by the transformer 2 and applied to the discharge lamp 4. It is well known that a single discharge lamp lighting device has a configuration in which four discharge lamps are subjected to heavy pressure f/rl, thereby starting the discharge lamp and maintaining the lighting state.

In the configuration shown in the figure, a circuit is opened between ll- and the power supply terminal l and the transformer 2 (the parts between them are designated as a and b), and a bidirectional switching device 5 is inserted between them. do. Specifically, the switching device 5 is constituted by a full-wave rectifier 6 and a transistor≠1 switching element 7, and each AC input terminal of the full-wave rectifier M6 is connected to one of the parts a and b described above. According to the configuration, one switching element 2 is turned on, and h is one lightning source terminal 1 and transformer 2. If you turn off the connection once and for all, the spear's connection will be severed. Therefore, when the voltage applied to the power supply terminal l is 0, f'L7 - at its wave crest and wave tail in each half-wave waveform of heavy pressure - the switching element wa is turned off, h is applied to the first discharge lamp 4, and the lightning pressure is the second. It will be easy to understand that the voltage will have a waveform as shown in B in the figure.

The wavefront of the voltage waveform described above, '19. The configuration for cutting the tail is illustrated in the following 1/77 Figure 3. The alternating current voltage applied to the power supply terminal l is stepped down to an appropriate value by a transformer 9 and full-wave rectified by a full-wave rectifier circuit 10.

The voltage obtained by full-wave rectification is ■. is given by a smoothing capacitor 121 via a diode 1 - where the smoothness f'I is given. - A smoothed direct lightning pressure element (for example, a Zener I diode) 13 is given - 71 Here, the force pressure is converted to pressure.Then, it is used as an operating link for comparator 4, and a reference lightning pressure E is created by the variable resistor 15 and resistor 16.This reference pressure is The magnitude Il- of E can be adjusted as appropriate by adjusting the resistance value of the variable resistor 15.

IA is given to the half terminal of the deductive amplifier constituting the reference voltmeter go comparator 14.

Voltage ■, one resistor, and 1B can be used to divide the voltage and create a non-lightning pressure corresponding to the city pressure. FIG. 4 shows the waveform of the voltage . FIG. 4 also shows the relationship between the voltage (2) and the basic lightning pressure (E). Voltage Comparator] Is it input to one terminal of 4? Ru. Comparator 14 digits Voltage L V as above
Assume that the input voltage is greater than the basic lightning pressure E (C) and the output is O.Other than this, try outputting a -H level.The voltage V is divided by the resistor 19.20 A corresponding voltage is applied to the output terminal of the calibrator 14 and the base of the transistor 2 constituting the switching element.

Transistor 21 collector I, Emitsu J 1141 K
ld - voltage ■. -b (when applied), the transistor 21 is connected to the base of the switching element 7.

In the above configuration, in the range where the voltage 2 is lower than the reference voltage E, the output of the comparator 14 is FiH, and therefore the base voltage 7 is connected to the base of the transistor 21 via the resistor 19.
5: The supplied h2 transistor J21 is turned on.

When this is turned on, the switching element 7 is turned off, so that the voltage applied to the power supply terminal 117) is applied to the transformer 2. When the voltage ■ exceeds the reference voltage E, one comparator 14
When the force output becomes 0, the 20 resistors are short-circuited, and the base current flows through the runges 21, turning it off forever. Then, the switching element 7 is turned on and the voltage source terminal 1 is turned on.
voltage is applied to the transformer 2. Voltage ■ is reference voltage E
The lower range exists at the wavefront and wavetail of each half-wave waveform of voltage ■. Therefore, the waveform of the voltage applied to the transformer 2, that is, the voltage applied to the discharge lamp 3, has a lifetime waveform as shown in B of FIG. As a result, the wave crest,
The tail of the wave is cut and the pressure of love is applied to the discharge lamp f'L
I noticed that the light was a little darker than usual. That is, since the light is to be dimmed, Ao and the amount of dimming can be changed by adjusting the standard pressure E.

In the 31st configuration, one comparator 14 is used to compare one voltage V and the reference voltage E and cut off the wave front and wave tail of each half fg1 waveform of 1'C voltage. 441 circuit may be used instead of L/'+, for example, as shown in the 6th line, every half wave of one voltage - until the voltage crosses zero or the required time T1 elapses. - and similarly, even if the voltage applied to the discharge lamp is cut until it does not cross K0 after the required time T2 has elapsed, it is possible to cut the first wave crest and the first wave tail. In configuration 3-, the cutting time between the wave crest and the wave tail is the same, so when setting the times TI and T* using the 441 circuit as described above, if each time is set appropriately, the cutting time between the wave crest and the wave tail is the same. It is possible to vary the cutting time.

This shows an example of the configuration when the fifth circuit 441 is used. Power> The same figure as the first 3M is omitted. 31, 32. -441 circuit 31 with ld/fima circuit
The timer circuit 32 sets the time T and the time TP. Both circuits 31.32 digits (8 digits - programmers)
The configuration uses unijunction transistors (hereinafter referred to as PUT) 33.34. The time setting depends on the time constant fl determined by the capacitor 35.degree. 36 and the resistor 3'/3B. This type of timer circuit has a well-known structure.

When the voltage waveform of the power supply Mizuko crosses the army, it is T for an hour.
, it is considered as -PUT 33 Gaon.

Is it because the tote transistor 〃4〕 is turned on and pulled? −
f-I! ? Transis J iL2 which was supposed to be f-on
Kaofu and Sa'FIru. Scary, the switching element 7 is turned on by the IC, and the AC voltage at the lightning source terminal l is changed to the transformer 2.
Nami is applied to minus. When time 'I'2 has elapsed, -PUT 3a is turned on next. When the transistor 43 turns on, the transistor 44 also turns on, and the transistor 65 turns on from fLK. Since the transistor J15 is connected in parallel with the transistor i42, the transistor 42 was previously turned off, and when the motor transistor L5 is turned on, the transistor 942 is short-circuited, and the switching element 7 is turned off. I end up.

By kneading, application of the AC voltage from the power supply terminal l to the one transformer 2 is stopped. When this cross-hat voltage waveform crosses the wing, PUTs 33 and 34 are both turned off f'L. Repeat the fear below. As a result of the above, a voltage is applied to the discharge lamp 3 as shown in FIG. 6, when the time .

Note that the maximum amplitude portion of the voltage waveform is made to exist between the negative time T1 and the time Tp and t, as in the case of the third male. Also, as mentioned above, when the period of a half wave of the voltage waveform is T, one hour T and the time (T-T) do not necessarily have to be the same.

As described in detail above, the present invention has the effect of making it possible to dim the discharge lamp without causing difficulty in turning it off and starting it.

[Brief explanation of the drawing]

The 1st M is a waveform for explaining the conventional dimming principle.
&ld Waveform M for explaining the dimming principle of this invention - No. 3 A is a circuit diagram showing an embodiment of this invention, No. 41 is a waveform for explaining operation - Fig. 5 is another embodiment of this invention FIG. 6 is a waveform diagram of the circuit illustrating an example of the operation. l...AC power supply terminal-2...Transformer-3...
...Discharge lamp, 5... Switching device-7...
... Switching element-13... Constant voltage element,
]4... Comparator, 15 ・Variable resistor -31, 32
・・・・・・Ima circuit-37゜38・・・Variable resistance patent applicant Meiji National Industries Co., Ltd. Agent Kinnosuke Nakazawa Figure 5, Garden 6

Claims (1)

[Claims] a snow pressure applying means for starting the discharge lamp and applying an alternating lightning pressure to keep it lit; A waveform cutting means for cutting the wavefront and the wavetail of the waveform while leaving the maximum amplitude value of the waveform, and a variable cutting time for changing the cutting time of the waveform's wavefront and wavetail for dimming by the waveform cutting means. A discharge lamp dimmer comprising means.