JPH0118560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp lighting device, and more particularly to a discharge lamp lighting device used by being connected to a dimmer.

2. Description of the Related Art Conventionally, a discharge lamp lighting device that dims and lights a discharge lamp by inputting phase-controlled power is known, for example, as shown in FIG. 1. This kind of device 1
comprises a rectifier 2 and an inverter lighting circuit 3, controls the lighting phase angle φ _A of each half cycle by a dimmer 5 connected to a commercial power supply 4, and inputs this output voltage to control the lighting phase angle φ A of a discharge lamp 6, e.g. Turn on the fluorescent lamp.

However, according to this type of device 1, dimming lighting of the discharge lamp 6 is performed by controlling the ignition phase angle (conduction angle) by the dimmer 5, and adjusting the ignition phase angle φ _A and π radian in each half cycle. Widen the conduction period between
Although the light intensity of the discharge lamp 6 is varied by narrowly changing it, the upper limit of the dimming lighting range is regulated by the discharge starting voltage of the discharge lamp 6. Therefore, when the secondary voltage is set to a certain constant value, The drawback was that it was extremely narrow.

The present invention was developed in view of the above-mentioned drawbacks of the prior art, and provides a discharge lamp that has a wide dimming range and that does not flicker even with sudden changes in power waveform distortion, etc. The purpose is to provide an electric light lighting device.

In order to achieve this object, the present invention provides a discharge lamp lighting device that dims and lights a discharge lamp with a voltage that controls the ignition phase angle of each half cycle of an AC power source.
means for detecting a change in the firing phase angle for each half cycle, means for distinguishing between steady and transient changes in the firing phase angle, and for steady changes in the firing phase angle; The extinguishing phase angle is determined according to the ignition phase angle, and the extinguishing phase angle is determined so that the phase angle difference from the ignition phase angle becomes a constant value in response to a transient change in the ignition phase angle. A phase control circuit is provided.

Embodiments of the invention will be described below with reference to the accompanying drawings.

FIG. 2 is a block diagram showing the configuration of a discharge lamp lighting device according to the present invention, and this discharge lamp lighting device 11 includes a rectifier 12, an inverter lighting circuit 1
3, and an internal phase control circuit 14 provided between the rectifier 12 and the inverter lighting circuit 13, the power whose phase is controlled by the dimmer 5 is inputted through two power supply wirings, and the discharge lamp 6, e.g. Dim and turn on the light lamp.

Here, the dimmer 5 is a device that continuously changes the brightness of the discharge lamp 6 by controlling the ignition phase angle φ _A of each half cycle in the voltage waveform of the commercial power supply 4 connected to its input side. As is widely known in the past, it is composed of a thyristor or the like. The control range of the ignition phase angle φ _A is, for example, from zero to 0.5π for each half cycle, from the relationship with the discharge starting voltage of the discharge lamp 6.
It is set to around radians.

Also, of the discharge lamp lighting device 11, the rectifier 12
Various discharge lamp lighting circuits including an inverter lighting circuit 13 have been proposed in the past, in which the alternating current output of the dimmer 5 is full-wave rectified by a rectifier 12, and this rectified voltage is made up of transistors, thyristor inverters, etc. The inverter lighting circuit 13 converts the voltage into a high frequency voltage (for example, several kHz or more) and lights the discharge lamp 6. A phase control circuit 14 is connected between the rectifier 12 and the inverter lighting circuit 13 via input terminals a, c and output terminals b, d.

FIG. 3 is an explanatory diagram of one embodiment of this phase control circuit 14, in which figure A is a block diagram and figure B is a block diagram.
is a circuit diagram roughly corresponding to Figure A, and furthermore, the fourth
The figure is a waveform diagram of each part of this phase control circuit. This phase control circuit 14 generates an extinguishing phase angle φ B in relation to the ignition phase angle φ _A of each half cycle of the output waveform of the rectifier 12, and generates an extinguishing phase angle φ _B in relation to the ignition phase angle φ B normally performed by the dimmer 5. For steady changes in the angle φ _A , the extinction phase angle φ _B is changed in response to the change, while for rapid transient changes in the ignition phase angle φ _A due to waveform distortion of the power supply voltage, etc. Then, the extinguishing phase angle φ _B is varied so that the phase angle difference φ ₀ between the extinguishing phase angle φ _B and the firing phase angle φ _A becomes _a constant value. A means for cutting the latter half of a half cycle and detecting a change in the firing phase angle φ _A of each half cycle _;
A _means for determining whether a steady change or a transient change in _the firing phase angle _φ This firing phase angle φ _A
and means for determining the extinction phase angle φ _B such that the phase angle difference φ ₀ with respect to the arc extinguishing phase angle φ B becomes a constant value.

That is _, when the output voltage V _io of the rectifier 12 as shown in FIG.

The level determination circuit 21 detects a change in the firing phase angle φ _A in each half cycle, and is connected to a resistor R ₁ ,
R ₁ ′ and transistor T _r1 , the input voltage
When V _io falls below the determination level, that is, from time t ₀ to time t ₁ shown in FIG. 4B, a rectangular output is produced. The rising time t ₀ of this output is constant, but the falling time t ₁ becomes correspondingly longer as the ignition phase angle φ _A increases, and is determined by a predetermined maximum value of the ignition phase angle φ _A , e.g. The falling point becomes long until around 0.5π radian. The output of this level determination circuit 21 is applied to a clear circuit 22, a first integration circuit 23, and a second integration circuit 24.

The clear circuit 22 is composed of a capacitor C ₂ , a resistor R ₂ and a transistor T _r2 , and outputs a clear signal at the rising time t ₀ of the output of the level determination circuit 21 (FIG. 4C), which is applied to the first integrating circuit 23. .

The first integrating circuit 23 consists of a resistor R ₃ and a capacitor C ₃ , and integrates the output of the level determination circuit 21. When the clear signal is applied to the first integrating circuit 23, the integrated output is cleared and then The output of the level determination circuit 21 is integrated again. That is, as shown in FIG. 4D, the first integrating circuit 23 starts integration after being cleared by the clear signal, and at the falling point t ₁ of the output of the level determining circuit 21.
It continues to integrate until then, holds that integrated value, is cleared by the next clear signal, and starts integrating again.
The output voltage of the first integrating circuit 23 changes depending on the length of the output voltage of the level determination circuit 21 (from the rising time _t0 to the falling time _t1 ). That is, as the ignition phase angle φ _A increases, the maximum output voltage V 23 of the first integrating circuit 23 increases, and on the other hand, as the ignition phase angle φ _A decreases, the maximum output voltage V ₂₃ increases accordingly. Voltage V ₂₃ becomes smaller. At this time, steady changes in the ignition phase angle φ _A over a long period of time, which are normally performed by the dimmer 5 for dimming adjustment, and sudden shortening of the ignition phase angle φ _A due to fluctuations in power supply voltage distortion, etc. The maximum output voltage V ₂₃ of the first integrating circuit 23 changes in response to time fluctuations (transient changes), and this output V ₂₃ is applied to the differential amplifier 25 and the timer circuit 26 .

On the other hand, the second integration circuit 24 is composed of resistors R ₄ , R ₄ ' and a capacitor C ₄ , and is configured with a low-pass filter, integrates the output of the level determination circuit 21, stores it, and outputs the stored integral output. is added to the differential amplifier 25. Therefore, in this second integrating circuit 24, similarly to the first integrating circuit 23,
The output of the level judgment circuit 21 is integrated, but since this second integration circuit 24 is composed of a low-pass filter, a sudden shortening of the firing phase angle φ _A (that is, the fall timing t ₁ of the level judgment circuit output) It does not respond to time fluctuations, but responds to long-term changes in the ignition phase angle φ _A , integrates the output of the level judgment circuit 21, stores it, and outputs it to the differential amplifier 25. Add. Therefore, the first integrating circuit 23 and the second integrating circuit 24 determine whether the ignition phase angle φ _A is a steady change or a transient change.

The differential amplifier 25 receives the outputs of the first integrating circuit 23 and the second integrating circuit 24, and when a difference occurs between the two input values, the difference is amplified and added to the timer circuit 26. That is, when the ignition phase angle φ _A changes over a long period of time, the length of the output voltage of the level determination circuit 21 changes accordingly, and the output of this level determination circuit 21 is
3 and the second integrating circuit 24, both input voltages of the differential amplifier 25 become equal and the output becomes zero, so the first integrating circuit 23
Only the output of will be applied to the timer circuit 26. On the other hand, if the ignition phase angle φ _{A suddenly fluctuates back and forth for a short time while the ignition phase angle φ A is} stopped at a certain value, the first
Since the output of the integrating circuit 23 fluctuates, the output of the first integrating circuit 23 does not fluctuate.
4, this differential amplifier 25
A negative correction value is output from the first integrating circuit 2, while the first integrating circuit 2
When the output of the second integrating circuit 24 becomes smaller than the output of the second integrating circuit 24, a positive correction value is output from the differential amplifier 25, and this correction amount is added to the timer circuit 26.

The timer circuit 26 is integrated with the differential amplifier 25 and determines the extinguishing phase angle φ _B in response to steady changes in the ignition phase angle φ _A , while the ignition phase angle φ For transient changes in _A , the extinguishing phase angle φ _B is determined so that the phase angle difference φ ₀ from the ignition phase angle φ _A is a constant value. transistor
PUT, resistor R _6A and capacitor C ₆ on the anode side (A side), resistor R _6G and Zener diode ZD ₆ on the gate side (G side), cathode side (K
The first integrating circuit ₂₃ and the differential amplifier 25 are further connected to the anode side. Resistor R _6A and capacitor C ₆ on the anode side form the integrator circuit, resistor R _6G on the gate side and Zener diode ZD ₆
constitute a constant voltage source, respectively. This timer circuit 26 provides a timer output (extinction phase angle φ _B control signal) at a phase angle related to the ignition phase angle φ _A of the input voltage V _io . That is, the anode side capacitor C ₆ in this timer circuit 26 is connected to the first capacitor C 6 .
Since the outputs of the integrating circuit 23 and the differential amplifier 25 are integrated, when the output of the differential amplifier 25 is zero, as shown by the solid line in FIG. The output voltage starts at , then rises, resulting in a sawtooth-shaped output voltage. Since a constant voltage E is applied to the gate side of this timer circuit 26 (timer gate voltage waveform in FIG. 4D),
The time t ₁₁ when this constant voltage E exceeds the anode side voltage
Then, the programmable union transistor PUT becomes conductive, and the timer output (extinguishing phase angle φ _B control signal) is output from the resistor R _6K . At the time point _t11 when the timer output is generated, as the ignition phase angle φ _A gradually increases, the output voltage of the first integrating circuit 23 increases correspondingly, and the rising angle of the anode side voltage of the timer circuit 26 also increases. becomes larger, so the point at which this timer output occurs
t ₁₁ will also be faster. However, when the ignition phase angle _φA is stopped at a certain value, if the ignition phase angle _φA changes rapidly back and forth due to fluctuations in the power supply waveform, etc., the correction value becomes Because it comes out of the amplifier 25 and is added to the anode side of this timer circuit 26, the slope angle of the timer anode curve changes. That is, when the ignition phase angle φ _A slightly changes by +Δφ _A , the inclination angle of the timer anode curve becomes smaller, so that the point of intersection with the timer gate straight line shifts backward, and the minute period corresponding to +Δφ _A +
The output generation of the timer 26 is delayed by Δt ₁₁ (4th
(dotted and dashed lines in Figures A and D), while the firing phase angle φ _A is -
When there is a minute change by Δφ _A , the effect is exactly opposite to that described above, and the output generation of the timer circuit 26 is accelerated by the minute period −Δt ₁₁ corresponding to −Δφ _A (two-dot chain lines in Fig. 4 A and D). . Therefore, the interval between the ignition phase angle φ _A and the timer output generation time t ₁₁ is maintained at a constant value. The outputs of these timer circuits 26 are applied to a control switch 28 via a control circuit 27.

The control output circuit 27 consists of a thyristor SCR ₇ , and when the output from the resistor R _6K of the timer circuit 26 is input to the gate of this thyristor SCR ₇ , it becomes closed and the output voltage is changed to the control switch 28.
Add to. This control switch 28 consists of a transistor T _r8 , and since the output of the control output circuit 27 is applied in the opposite direction between the emitter and base of this transistor T _r8 , the input terminal C and the output terminal d of this control switch 28 Switch between the closed state and the open state. Therefore, the level determination circuit 21
At the output terminal b connected through a diode 29 to the input voltage V _io , an output voltage V _put of a so-called double-cut waveform appears, in which the latter half of each half cycle of the input voltage V io is cut off at the extinction phase angle φ _B . This output voltage V _put
Since the extinction phase angle _{φ B of} φ _B ) also decreases from π radian to 0.5π radian, but if the ignition phase angle φ _A is stopped at a certain value, even if the ignition phase angle φ _A changes rapidly back and forth, , the extinction phase angle φ _B also fluctuates in the same direction by the same amount as the amount of variation, so the phase angle difference (conduction period) φ ₀ between the extinction phase angle φ _B and the firing phase angle φ _A is a constant value. (Figure 4). Note that when the ignition phase angle φ _A of the input voltage V _io is zero (at full light), the control switch 28 remains closed, so the input voltage V _io is applied to the output terminal b via the diode 29. Output voltage of intact waveform
V _put appears.

Next, the operation of the above embodiment will be further explained.

During full light mode (φ=0) when the phase of the commercial power supply 4 is not controlled by the dimmer 5, the AC voltage of the commercial power supply 4 is directly rectified by the rectifier 12, and this output is sent to the phase control circuit 14. Figure 5 through
The waveform as shown in _A1 is inputted to the inverter lighting circuit 13 as it is, and the discharge lamp 6 is lit with the lamp current having the waveform as shown in FIG. _5A2 .

On the other hand, during dimming in which the ignition phase angle φ _A is controlled by the dimmer 5, the ignition phase angle φ _A changes from zero to
If you increase it in the direction of 0.5π radian, this dimmer 5
The output is full-wave rectified by the rectifier 12 and applied to the phase control circuit 14. In this control circuit 14, as the ignition phase angle φ _A increases, the first
The output of the timer circuit 26 decreases from π radian to 0.5π radian via the integrator circuit 23, so that the ignition phase angle φ _B of each half cycle corresponds to the ignition phase angle φ _A of the same half cycle. The latter half is cut off, and a voltage with a so-called double cut waveform as shown in FIG. _5B1 is output. This output voltage is applied to the inverter lighting circuit 13, and a lamp current as shown in FIG. _5B2 flows through the discharge lamp 6, and the discharge lamp 6 is dimmed and lit by this current. Therefore, the conduction angle can be changed over a wide range including the peak value of the power supply voltage (0.5π radian), and the dimming range is significantly widened.

However, when the ignition phase angle _φA is stopped at a certain value, if the ignition phase angle _φA suddenly changes slightly back and forth due to voltage waveform distortion in the commercial power supply 4, The amount of variation ±Δφ _A is detected by the first integrating circuit 23 and the second integrating circuit 24 , and the amount of correction for the amount of variation ±Δφ _A is output from the differential amplifier 25 and added to the timer circuit 26 . Therefore, the timer circuit 26 outputs the extinguishing phase angle φ _B control signal that fluctuates in the same direction by the same amount as the fluctuation amount ±Δφ _A , so that the extinguishing phase angle φ _B and the ignition phase angle φ _A are The phase angle difference φ ₀ becomes a constant value, and while the conventional dimmer 5 is used, it is possible to prevent the discharge lamp 6 from flickering due to sudden fluctuations in the conduction period φ ₀ .

Since the device according to the present invention is configured as described above, the second half of the same half cycle is cut at the extinction phase angle corresponding to the ignition phase angle of each half cycle controlled by dimming, and this point is Since the light intensity of the discharge lamp is adjusted by widening or narrowing the conduction period between the arc phase angle and the extinction phase angle, the light intensity of the discharge lamp can be minimized at a phase angle of around 0.5π radian, making it easier to use conventional dimmers. This has the effect of making it possible to utilize the peak value of the power supply voltage while using the LED, and significantly widening the dimming range. Moreover, if the ignition phase angle suddenly undergoes a small change (transient change) back and forth due to power waveform distortion, etc., the extinction phase angle will also change in the same direction as the small change, so the conduction period will remain constant. This has the effect of preventing the discharge lamp from flickering due to rapid fluctuations in the conduction period.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional two-wire power supply discharge lamp lighting device, Fig. 2 is a block diagram showing the configuration of the discharge lamp lighting device according to the present invention, and Fig. 3 is a diagram showing the discharge lamp lighting device of Fig. 2. FIG. 5 is an explanatory diagram of the phase control circuit in the device, where FIG. A is a block diagram, FIG. B is a circuit diagram almost corresponding to FIG. A, FIG. 4 is a waveform diagram of various parts of the phase control circuit in FIG. 3, and FIG. is an input/output waveform diagram of the inverter lighting circuit in the block diagram of FIG. 2; 1, 11... Discharge lamp lighting device, 2, 12... Rectifier, 3, 13... Inverter lighting circuit, 6...
Discharge lamp, 14... Phase control circuit, 21... Level determination circuit, 23... First integrating circuit, 24... Second
Integrating circuit, 25... differential amplifier, 26... timer circuit.

Claims (1)

[Claims] 1. In a discharge lamp lighting device that dims and lights a discharge lamp with a voltage that controls the ignition phase angle of each half cycle of an AC power supply, means for detecting a change in the ignition phase angle of each half cycle; A means for distinguishing between a steady change and a transient change in the firing angle, and a means for determining an extinction phase angle in accordance with a steady change in the firing phase angle, and a means for determining an extinction phase angle in response to a steady change in the firing phase angle, and A discharge lamp lighting device comprising a phase control circuit having means for determining an extinguishing phase angle so that the phase angle difference between the ignition phase angle and the ignition phase angle is a constant value.