JPH0317999A - Electric discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To obtain a wide dimming range by a method wherein the luminance of an electric discharge lamp is changed at a larger rate of change than the rate of change in the current flow phase angle of a phase control dimmer. CONSTITUTION:To improve the startability, the lighting circuit is held out of functioning when the output of a phase control dimmer, which is applied across the input power terminals 25, 26, is below 50%. At the same time, to widen the dimming range, data of the phase control dimmer and data of the output frequency are provided to be combined by the logic circuit 16 so that the luminance can be adjusted over a wider range such as 30% through 100% when the available dynamic range of the current flow phase angle of the phase control light adjustment unit 21 is 50% through 100%. Thus, light adjustment over a wide range is possible even if the output of the phase control light dimmer 21 is limited to 50% through 100%. The lighting circuit is held out of functioning when the output of the phase control light dimmer 21 falls below 50%. Accordingly, a decrease in the life time of the electric discharge lamp 7 due to startability troubles is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for lighting a discharge lamp using an electronic circuit, and more particularly to a discharge lamp lighting device suitable for dimming a discharge lamp. [Prior Art] As described in Japanese Unexamined Patent Application Publication No. 63-81795, in the conventional device, when the output of a phase control dimmer is applied to the power input terminal, the power input terminal and the rectifying/smoothing The voltage waveform between the circuit's low-voltage side output is resistance-divided using two resistors connected in series, and then input manually to a voltage comparator. 'f! The L voltage comparator compares a certain reference voltage with the above voltage, counts the number of clocks from the clock generator input to the counter during periods when the output of the voltage comparator is positive and negative, and calculates the difference between the counted numbers. is calculated, obtains dimming information, digitally calculates the reference clock according to this dimming information, creates a switch opening/closing control signal, and performs dimming while controlling the duty of opening/closing the switch. Ta.

[Problem to be solved by the invention]

In the above conventional technology, when the output of the phase control dimmer applied to the power supply terminal is 50% or less, the peak power supply voltage drops and the voltage applied to the discharge lamp also decreases, resulting in the start of the lamp. sex has decreased. Therefore, the lighting circuit was made not to operate when the flow angle of the phase control dimmer was 50% or less. Therefore, the brightness control of the discharge lamp III
1@Open also had the disadvantage of being subject to restrictions.

An object of the present invention is to provide a device that can provide a wide dimming range.

[Means to solve the problem]

To achieve the above purpose, in order to improve startability, when the output of the phase control dimmer applied to the power input terminal is less than 50%, the illuminated garden path is not activated, and the dimming is disabled. In order to widen the range, the data of the phase control dimmer and the output frequency data are combined. j
# is connected using a logic circuit, and the flow angle change range of the phase control dimmer that can be used is 50% to 100%, for example, the brightness is 30% to 100%, etc. It was made to be wider.

[Rules]

Determine the relationship between brightness and output frequency in advance, and set 100% of the data coming from the phase control dimmer to the frequency corresponding to 100% of the brightness, and 50% of the data coming from the phase control dimmer to the frequency corresponding to 100% of the brightness. For example, a logic circuit is used to adjust the frequency to correspond to 30% of the brightness, thereby widening the brightness control range.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on Figure +m.

FIG.
is a capacitor, 5 is a preheating choke, 6 is a preheating capacitor, 7 is a discharge lamp equipped with discharge lamp electrodes 8 and 9, l
O is a switch element, 13 is a voltage waveform detection circuit consisting of resistors 11 and 12, and 19 is an adjustment consisting of a voltage comparator 14, a counter 15, a logic circuit 16, a reference voltage power source 17, and a clock generator 8. Optical information detector, 20 is a clock generator, 21 is a phase control dimming circuit 1, 22 is an AC power supply, 23 is a control signal for the switch cable 10, 24 is a manual terminal for the dimming information detector 9, 25 and 26 are tunyuan human power terminals, and 27 is a control terminal of the switch element 10.

First, the basic operation of lighting the discharge lamp 7 of this circuit will be explained. For starting operation, the switch element 10 is connected to the control circuit 2.
3, the choke 3, preheating choke 5, capacitor 4, and preheating capacitor 6 resonate, and the preheating choke 5 and preheating capacitor 6 are connected in parallel via the discharge lamp electrodes 8 and 9. Flow current through the circuit. In this way, the discharge lamp electrodes 8 and 9 are preheated. Further, the voltage across the parallel circuit of the preheating choke 5 and the preheating capacitor 6 is applied to the discharge lamp 7 to turn it on. The dimming of this circuit is performed by controlling the opening/closing period of the switch element 10 using the control signal 23 of the switch control circuit 2.

According to the circuit configuration shown in Figure ↓, when the output of the phase control dimmer 21 is applied to the power supply terminals 25 and 26,
The voltage waveform of the voltage waveform between the power source terminal 25 (re) and the output on the substitute voltage side on the rectified and smoothed (b) road is resistively divided using the resistors 1l and 12, and the waveform is the waveform shown in Figure 2 (a). Tomuru. In the waveform diagram of FIG. 2(a), the broken line indicates a waveform that is not subject to flow angle control. Therefore, the voltage comparator 14 outputs the waveform shown in FIG. 2(b). In addition, in the waveform diagram of Fig. 2(b), the waveforms l, N, and U are output from the voltage comparator l4 when the waveforms il and h are subjected to flow angle control at the human input terminals. This shows that.

Next, the output of the voltage comparator 14 is outputted from the clock generator l8 which is inputted to the counter 15 during the positive period (FIG. 2).
The number of clocks shown in c) is counted, the flow angle of the phase control dimmer is determined from the number, and the duty is calculated. Then, dimming information is obtained from the logic port 16 set so that the duty of the phase control dimmer from 100% to 50% corresponds to, for example, the brightness of 100% to 30%. This light control information is sent to the switch control path 2, and the light is controlled by controlling the switch element 10 to change the frequency. FIG. 4 shows the results of measuring the relationship between brightness and frequency using circuit components with an excessive number of constants in the lighting circuit of this construction. Further, by setting the logic circuit in the relationship between the manually input flow angle and the output frequency as shown in FIG. 5, the dimming characteristics as shown in FIG. 3 can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to provide a dimmer that allows dimming over a wide range even if the output of the phase control dimmer used is limited to 50% to 100%. can. At the same time, if the output of the phase control dimmer is less than 50%, the operation of the lighting circuit is stopped, so it is possible to prevent the life of the discharge lamp from deteriorating due to poor starting.

[Brief explanation of the drawing]

Fig. 2 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is a waveform diagram explaining the operation of a circuit that detects dimming information, and Fig. 3 is a distribution diagram of a phase control dimmer according to an embodiment of the present invention. Figure 4 is a measurement diagram showing the relationship between angle and brightness, Figure 4 is a curve diagram representing the relationship between brightness and frequency, and Figure 5 is a curve circle representing the relationship between flow angle and frequency of a phase control dimmer. ．． 2...Switch control path, 3...Choke, 4...
- Capacitor, 5... Preheating choke, 6... Preheating capacitor, IO... Switch element, 15... Counter, l6... Logic circuit. f, x position (ku) (1)) (0) Name 3 AL.梠 System qP Decoration T! ! 5 Kushi Nishi (%) - Ikani, 8 hand system 41 ≧P Storet Kurashi Ekaku (φ) 1 - →

Claims (1)

[Claims] 1. In a discharge lamp lighting device having at least one switch element that measures a flow angle of a phase control dimmer and controls an output current based on the measurement result, the flow angle change rate of the phase control dimmer A discharge lamp lighting device characterized by changing brightness at a rate of change greater than .