JP2006059608A - Discharge lamp control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp control device in which energy saving can be achieved. <P>SOLUTION: Respective neon transformers 8 of the discharge lamp control device 1 are connected to a CPU 5 via a photocoupler (optical sensor). The photocoupler is composed of light emitting elements 31a to 33a connected to the CPU 5, and light receiving elements 31b to 33b connected to the neon transformers 8. In the CPU 5, on/off control of the photocoupler is carried out by a control signal Sx, and the discharge lamp is controlled by lighting (light control)/flashing on and off. That is, during outputting of the control signal Sx of H level, the photocuopler becomes to have on state, and have a state that circuits of the neon transformers 8 are short-circuited. On the other hand, during outputting of the control signal Sx of L level, the photocoupler becomes to have off state, and have a state that resonance circuits 30 of the neon transformers 8 are resonated, and that the output voltage Vb of high frequency is induced onto the secondary side of a transformer 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge lamp control device that drives and controls a discharge lamp such as a neon tube or an argon tube.

  Conventionally, discharge lamps (discharge tubes) are installed in buildings, signboards, etc. as night illumination. The discharge lamp is made of, for example, a neon tube or an argon tube, and is connected to the discharge lamp control device so as to be lit, flashing, and dimming controlled. This type of discharge lamp control device is a type that directly rectifies the output (AC voltage) of the commercial power source and transforms it directly to a high voltage with a converter transformer, or reduces the flickering of the discharge lamp and improves the luminous efficiency. There is a type that performs high-frequency conversion and transformation by an inverter transformer after full-wave rectification of the output. Then, the discharge lamp control device supplies the transformed high voltage to the secondary discharge lamp to light (dim) and blink the discharge lamp.

  Here, this type of discharge lamp control device is disclosed in Patent Document 1, for example. This discharge lamp control device performs lighting (dimming) / flashing control of the discharge lamp by performing on / off control, that is, phase control, of the output of the commercial power supply itself. That is, the discharge lamp control device has a switching element that can turn on and off the output of the commercial power supply, and outputs a control signal synchronized with the commercial power supply to the switching element, so that the output of the commercial power supply is output when the control signal is at the H level. It flows to the primary side of the transformer and controls the discharge lamp on the secondary side.

Further, when phase control is used in a discharge lamp control device using an inverter transformer, as shown in FIG. 6, the AC voltage waveform W1 is controlled in phase by controlling the AC voltage waveform W1 of the commercial power supply using a control signal. A converted voltage waveform W2 indicated by the alternate long and short dash line in FIG. As a result, the output voltage Vout on the secondary side is output at a high frequency having a value corresponding to the phase, and the discharge lamp is lit with a luminance corresponding to the output voltage Vout. And the brightness | luminance of a discharge lamp is controlled by changing the timing of this phase.
JP-A-7-160211 (page 3-4, Fig. 1)

  However, when phase control of the commercial power supply is used for controlling the discharge lamp, a switching loss is generated as much as the output of the commercial power supply is cut, and the commercial power supply power is wasted. In particular, since a large amount of current (for example, 1 A) flows from a commercial power source, when phase control is used for discharge lamp control, a switching loss becomes significant, and in order to save energy by suppressing the switching loss. A countermeasure was needed.

  As an example of a discharge lamp control device that transforms the output of a commercial power source with an inverter transformer, there is a discharge lamp control device shown in FIG. 7, for example. The discharge lamp control device includes a power supply control device 51 that performs on / off control (phase control) on the output of a commercial power supply, and a transformer 53 that corresponds to the number of discharge lamps 52. By the way, each transformer 53 is equipped with a full-wave rectifier circuit and a smoothing circuit. However, when phase control of a commercial power supply is used, it takes time to charge the capacitor forming the smoothing circuit and the capacitor in the inverter circuit. Even if 53 is activated, the output voltage Vout is not immediately output. Therefore, the output voltage Vout has a time lag as shown in FIG. 6 and the on-time of the output voltage Vout is shortened. As a result, the dimming performance is lowered and flickering occurs.

  Further, since each transformer 53 has a built-in full-wave rectifier circuit, the transformer 53 itself is in a large size state. Therefore, since the discharge lamp control device, that is, the entire system becomes large, there is a demand for miniaturizing the transformer 53 and the system as much as possible. Further, when each transformer 53 is connected to the power supply control device 51, it is necessary to connect each transformer 53 to the power supply control device 51, and there is a problem that a lot of wiring work is required. In particular, when the transformer 53 is added, the wiring work increases accordingly, and the problem that the wiring work becomes troublesome becomes remarkable.

  An object of the present invention is to provide a discharge lamp control device capable of saving energy.

  In order to solve the above problem, in the invention according to claim 1, the input voltage input from the power source is rectified by a rectifier circuit, and the input voltage smoothed by the smoothing circuit after rectification is transformed to a high voltage by a transformer. In the discharge lamp control device for lighting or blinking the discharge lamp connected to the secondary side of the transformer with the high voltage, the input voltage after rectification is connected between the rectifier circuit and the transformer. The present invention includes a switching element that turns on / off the application of the input voltage to the transformer, and a control circuit that controls the application of the input voltage to the transformer by controlling the on / off of the switching element.

  According to the present invention, when the switching element is controlled to be in the ON state, the input voltage is short-circuited and application of the input voltage to the transformer is restricted, and no voltage is applied to the discharge lamp. On the other hand, for example, when the switching element is controlled to be turned off by the control signal, application of the input voltage to the transformer is permitted, and a high voltage from the transformer is applied to the discharge lamp so that the discharge lamp is turned on or blinked. Become. Therefore, even if the discharge lamp lighting (dimming) / flashing control is performed, the input voltage itself is not controlled, so that it is not necessary to perform a process of cutting the input voltage. It does not occur and energy saving can be achieved.

  According to a second aspect of the present invention, in the first aspect of the present invention, the primary winding of the transformer having an intermediate tap is connected in parallel between the input terminals of the pair of resonant second switching elements. Similarly, a resonance capacitor is connected in parallel between the input terminals of the second switching element, and the second switching element is alternately induced at the resonance frequency of the primary winding of the transformer. A resonance circuit having both ends of a feedback winding connected to a control terminal of the second switching element is provided. The control circuit performs on / off control of the switching element based on a control signal, so that the resonance circuit resonates with the input voltage. The gist of the invention is to control the application of the input voltage to the transformer.

  According to the present invention, when the input voltage is applied to the discharge lamp control device, the magnetic field is alternately induced in the primary winding and flows in the feedback winding when the operation of the invention of claim 1 is applied. The second switching elements are alternately turned on by the current, and the resonance circuit enters a resonance state. Therefore, a high voltage is generated in the secondary winding of the transformer, and the discharge lamp is turned on or blinked by this high voltage. Therefore, even in such a resonance type discharge lamp control device, an energy saving effect associated with a reduction in switching loss can be obtained.

According to a third aspect of the present invention, the gist of the invention according to the first or second aspect is that the switching element is connected to a downstream side of the smoothing circuit.
By the way, a capacitor or the like is used in this type of smoothing circuit, and when the input voltage is smoothed by the smoothing circuit when the discharge lamp control device is operated, a charging time for the capacitor is required. However, according to the present invention, in addition to the operation of the invention described in claim 1 or 2, since the switching element is arranged on the downstream side of the smoothing circuit, the smoothing circuit ( The smoothing time of the capacitor) is not related, and the response of the secondary high voltage output to the control signal is improved. Accordingly, the time lag is reduced between the signal output of the control signal and the secondary high voltage output, the output time of the high voltage output is sufficiently secured, and the dimming performance is prevented from being lowered.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, each of the second switching elements includes a stable voltage supply circuit that supplies the input voltage as a stable voltage. The gist is that it is connected to the downstream side of the stable voltage supply circuit.

  By the way, when a capacitor is used in the stable voltage supply circuit, it takes time to charge the capacitor when the stable voltage supply circuit stabilizes the voltage applied to the transformer when the discharge lamp control device operates. However, according to the present invention, in addition to the operation of the invention described in claim 2 or 3, since the switching element is arranged on the downstream side of the stable voltage supply circuit, the switching element can be controlled stably by the control signal. Regardless of the charging time for the voltage supply circuit (capacitor), the responsiveness of the secondary high voltage output to the control signal is improved. Therefore, the time lag is further reduced between the signal output of the control signal and the secondary high voltage output, and the dimming performance deterioration suppressing effect is further enhanced as the output time of the high voltage output is secured.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the transformer and the switching element are connected in a set, and at least the set is made. A plurality of transformer units including a transformer and a switching element are provided, and the rectifier circuit is shared among the plurality of transformer units by connecting the plurality of transformer units in parallel to the rectifier circuit. This is the gist.

  According to this invention, in addition to the operation of the invention according to any one of claims 1 to 4, since the rectifier circuit is shared among a plurality of transformer units, a rectifier circuit is provided for each transformer unit. Compared to the case of preparation, the apparatus is downsized.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the switching element includes a light emitting element connected to the control circuit side and light from the light emitting element. And an optical sensor comprising a light receiving element connected to the transformer side.

  According to this invention, in addition to the operation of the invention according to any one of claims 1 to 5, the transformer and the control circuit are connected by the optical sensor, that is, an electrically separated circuit. . Therefore, for example, even if an overcurrent flows to the transformer side, it does not flow to the control circuit side, so that it is difficult for the control circuit to be destroyed due to the overcurrent flow.

  According to the present invention, a switching element that turns on / off application of the input voltage after rectification to the transformer side is provided, and the switching element is turned on / off by a control signal synchronized with the input voltage, whereby the input voltage to the transformer is set. Since the discharge lamp is controlled to be turned on (dimming) and blinked by controlling the application of energy, energy saving can be achieved.

(First embodiment)
Hereinafter, an embodiment of a discharge lamp control apparatus embodying the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a schematic configuration of the discharge lamp control device 1. The discharge lamp control device 1 has an input side connected to the commercial power source 2 and an output side connected to the discharge lamp 3, and turns on the discharge lamp 3 based on an input AC voltage (for example, about 100 V) Va input from the commercial power source 2. It is a device that controls light) and blinking. In the discharge lamp control device 1, a plurality of discharge lamps 3 are connected in parallel, and a plurality of (three in this example) discharge lamps 3, 3,. As the discharge lamp 3, for example, a neon tube or an argon tube is used, and when there are three discharge lamps as in this example, those having emission colors of R, G, and B are used.

  FIG. 3 is a circuit diagram showing an electrical configuration of the discharge lamp control device 1. The discharge lamp control device 1 is unitized by housing various devices constituting the device 1 in the case 4. The discharge lamp control device 1 includes a CPU 5 that controls the device 1 in an integrated manner, a ROM 6 that stores a control program for operating the device 1 and a lighting / flashing method of the discharge lamp 3 (hereinafter referred to as pattern data). It has. The CPU 5 operates based on the control program stored in the ROM 6 and controls the lighting (light control) and blinking of the discharge lamp 3.

  The discharge lamp control device 1 also includes a filter circuit 7 that performs noise removal processing (filter processing), overvoltage protection processing, and the like on the input AC voltage Va input from the commercial power supply 2. Furthermore, the discharge lamp control device 1 converts the input AC voltage Va into a high frequency and then transforms it to a high voltage, and supplies a plurality of inverter transformers (hereinafter referred to as neon transformers) that supply the transformed high voltage to the secondary discharge lamp 3. 8). The commercial power source 2 corresponds to a power source, the CPU 5 corresponds to a control circuit, and the neon transformer 8 corresponds to a transformer unit. Further, the input AC voltage Va corresponds to the input voltage.

  Connected to the output side of the filter circuit 7 is a full-wave rectifier circuit 9 for full-wave rectification of the input AC voltage Va from the commercial power supply 2. The full-wave rectifier circuit 9 is configured by bridge-connecting diodes, and full-wave rectifies the input AC voltage Va from which noise has been canceled by the filter circuit 7. A smoothing circuit 10 that smoothes the rectified input AC voltage Va is connected to the output side of the full-wave rectifier circuit 9. The smoothing circuit 10 is composed of an electrolytic capacitor, and smoothes and outputs the input AC voltage Va after full-wave rectification.

  A ripple capacitor 11 that absorbs the ripple of the input AC voltage is connected to both ends of the smoothing circuit 10. A control power supply circuit 12 that generates power for the CPU 5 is connected to both ends of the smoothing circuit 10. The control power circuit 12 generates drive power for the CPU 5 based on the input AC voltage Va and supplies it to the CPU 5. The filter circuit 7 is connected to a zero cross detection circuit 13 that detects whether or not the value of the input AC voltage Va is zero. The zero-cross detection circuit 13 sequentially monitors the input AC voltage Va, and detects a zero value at the time of rising of the input AC voltage Va (that is, when the voltage value becomes zero in the rising waveform), thereby generating a zero-cross signal (H level signal) Sa. Is output to the CPU 5.

  FIG. 4 is a circuit diagram showing an electrical configuration of the neon transformer 8. Here, since the three neon transformers 8 have the same circuit configuration, only one neon transformer 8 will be described here, but the other configurations are the same. The neon transformer 8 includes a transformer 14 that transforms the primary side input AC voltage Va to a high voltage and outputs it to the secondary side. The transformer 14 includes a primary winding 15 on the input side and a secondary side on the output side. Winding 16 is included. A resonant capacitor 17 constituting an inductance component of the transformer 14 and an LC resonance circuit is connected in parallel to both ends of the primary winding 15.

  The midpoint (intermediate tap) of the primary winding 15 is connected to the output terminal of the full-wave rectifier circuit 9 via the inductor 18. The inductor 18 is formed of a coil, for example, and makes the input AC voltage Va constant. A first FET 19 and a second FET 20 are connected to one end and the other end of the primary winding 15, respectively. For example, MOSFETs are used for the first FET 19 and the second FET 20, the drain terminal is connected to the primary winding 15, and the source terminal is connected to GND.

  A diode 21, a resistor 22, and an electrolytic capacitor 23 are connected in series between the output terminal of the inductor 18 and GND. Here, the electrolytic capacitor 23 is an element that supplies a stable voltage to the gate terminal side of the first FET 19 and the second FET 20. A Zener diode 24 is connected between the resistor 22 and the intermediate terminal of the electrolytic capacitor 23 and the GND to hold the voltage divided on the upstream side at a constant voltage value. The first FET 19 and the second FET 20 constitute a second switching element, and the electrolytic capacitor 23 corresponds to a stable voltage supply circuit.

  Both terminals of the Zener diode 24 are connected in parallel with a first voltage dividing resistor 25 and a second voltage dividing resistor 26 that use a bias voltage applied to the gate terminals of the first FET 19 and the second FET 20 as a constant voltage value. In the first voltage dividing resistor 25, the middle point of the resistors 25a and 25b is connected to the gate terminal of the first FET 19, and in the second voltage dividing resistor 26, the middle point of the resistors 26a and 26b is connected to the gate terminal of the second FET 20. Yes. A diode 27 is interposed between the output terminal of the inductor 18 and the cathode terminal of the Zener diode 24 with the anode facing the Zener diode 24 side.

  The secondary winding 16 is wound with a larger number of turns than the primary winding 15 in order to boost the voltage on the primary side. One end of the secondary winding 16 is connected to the discharge lamp 3 (see FIG. 1) via a current limiting capacitor 28. In addition, the neon transformer 8 includes a feedback winding 29 through which a current flows due to mutual induction with the primary winding 15. One end of the feedback winding 29 is connected to the middle point of the first voltage dividing resistor 25 (that is, the gate terminal of the first FET 19), and the other end is connected to the middle point of the second voltage dividing resistor 26 (that is, the gate of the second FET 20). Terminal). The primary winding 15, the resonance capacitor 17, the first FET 19, the second FET 20, and the feedback winding 29 constitute the self-excited resonance circuit 30 of this example.

  In the above configuration, when the input AC voltage Va is supplied from the commercial power supply 2 to each neon transformer 8, a bias voltage is applied to the gate terminals of the first FET 19 and the second FET 20, but between the gate and source of the first FET 19 and the second FET 20. The one with the smaller threshold voltage is turned on first. For example, if the first FET 19 is turned on first, the current flows through the resonance circuit 30 simultaneously with the current flowing through the inductor 18, the primary winding 15, and the first FET 19. At this time, the voltage due to the resonance current is fed back via the feedback winding 29, so that the first FET 19 is kept on and the second FET 20 is kept off.

  After a while, since the resonance current is inverted, the gate voltage of the first FET 19 becomes equal to or lower than the threshold voltage. Instead, the gate voltage of the second FET 20 becomes higher than the threshold voltage, and the second FET 20 is turned on. An antiphase resonance current flows. Also at this time, the voltage due to the resonance current is fed back through the feedback winding 29, the second FET 20 is kept off, and the second FET 20 is kept on. Then, when the first FET 19 and the second FET 20 are alternately turned on and off, the primary winding 15, the feedback winding 29 and the resonance capacitor 17 resonate, and the accompanying AC voltage is generated in the secondary winding 16. To do.

  The secondary winding 16 is in a state where a current in the same direction as the current flowing through the primary winding 15 flows, and induces a high-frequency voltage boosted by the turn ratio between the primary winding 15 and the secondary winding 16. The high-frequency output voltage Vb is supplied to the discharge lamp 3 through the current limiting capacitor 28. And when the output voltage Vb becomes more than a starting voltage, the discharge lamp 3 will be in the state which turned on or blinked.

  As shown in FIGS. 3 and 4, each neon transformer 8 is connected to the CPU 5 via photocouplers (photosensors) 31 to 33. The photocouplers 31 to 33 include light emitting elements 31 a to 33 a connected to the CPU 5 and light receiving elements 31 b to 33 b connected to the neon transformer 8. Each of the light receiving elements 31b to 33b is paired with each of the light emitting elements 31a to 33a, the collector terminal is connected to the positive electrode of the electrolytic capacitor 23 via the resistor 22a, and the emitter terminal is the negative electrode of the electrolytic capacitor 23, that is, GND. It is connected to the. Each of the light receiving elements 31 b to 33 b is connected in parallel to the upstream side at both ends of the Zener diode 24. Note that the photocouplers 31 to 33 correspond to switching elements.

  As shown in FIG. 3, the light emitting elements 31a to 33a have anode terminals connected to a power source and cathode terminals connected to transistors 34 to 36 via resistors. For example, FETs are used for the transistors 34 to 36, and their base terminals (control terminals) are connected to the output terminals 5 a to 5 c of the CPU 5. Further, the output terminals 5a to 5c of the CPU 5 are connected to a power source via resistors 37a to 37c, respectively. Inside the CPU 5, switch elements 38a to 38c are incorporated so as to form a pair with the output terminals 5a to 5c.

  The CPU 5 drives and controls the neon transformer 8 by performing on / off control of the photocouplers 31 to 33 based on the control program of the ROM 6. This will be described below. The CPU 5 controls the light emission / non-light emission of the light emitting elements 31a to 33a by controlling the on / off of the internal switch elements 38a to 38c by the control signal Sx in order to control the on / off of the photocouplers 31 to 33. . First, when the switch element 38a (38b, 38c) in the CPU 5 is turned on by the H level control signal Sx, the transistor 34 (35, 36) is turned on, and the light emitting element 31a (32a, 33a) is turned on. Become. Then, the light receiving element 31b (32b, 33b) receives light, the photocoupler 31 (32, 33) is turned on, and a current that should flow into the base terminals of the first FET 19 and the second FET 20 is short-circuited. Accordingly, the neon transformer 8 becomes inoperative and no voltage is supplied to the discharge lamp 3.

  On the other hand, when the switch element 38a (38b, 38c) in the CPU 5 is turned off by the L level control signal Sx, the transistor 34 (35, 36) is turned off, and the light emitting element 31a (32a, 33a) is in the non-light emitting state. It becomes. Then, the photocoupler 31 (32, 33) is deactivated, and the input AC voltage Va of the commercial power supply 2 is applied as a bias voltage to the base terminals of the first FET 19 and the second FET 20, and the primary winding 15 and the feedback winding 29. Then, resonance occurs in the resonance capacitor 17, and a high-frequency output voltage Vb is generated from the secondary winding 16.

  The CPU 5 outputs a control signal Sx in synchronization with the cycle of the input AC voltage Va of the commercial power supply 2. This operation will be described below. First, when the CPU 5 inputs a zero-cross signal from the zero-cross detection circuit 13 to perform lighting control (dimming control), the transistor 34 (35, 36) is turned off by the H-level control signal Sx. The light emitting element 31a (32a, 33a) is turned off, and this timing is determined according to the luminance of the discharge lamp 3. That is, if the luminance of the discharge lamp 3 is high, the falling timing of the control signal Sx is close to the voltage zero point Pa of the input AC voltage Va as shown in FIG. 2, and if the luminance of the discharge lamp 3 is low, the rising edge of the control signal Sx. The falling timing is a position away from the voltage zero point Pa of the input AC voltage Va.

  Therefore, when controlling the discharge lamp 3, the CPU 5 sets when to output the L-level control signal Sx from the start of control (that is, the time T1 shown in FIG. 2) according to the luminance, and the elapsed time from the start of control. Outputs an L level control signal Sx on condition that the time T1 has been reached. Therefore, when the L-level control signal Sx is output, the photocouplers 31 to 33 are turned off and the neon transformer 8 is operable, and resonance is caused by supplying the input AC voltage Va of the commercial power supply 2. The circuit 30 transmits and the discharge lamp 3 is lit. In addition, when there are a plurality of discharge lamps 3, it is possible to change the luminance of each discharge lamp 3 by changing the timing of the L level output of the control signal Sx.

  Further, the CPU 5 controls the signal level of the control signal Sx so that the rising timing at which the control signal Sx changes from the L level to the H level is synchronized with the falling zero point Pb (see FIG. 2) of the input AC voltage Va. Here, since the frequency of the commercial power source 2 is 50 Hz or 60 Hz, the half-cycle time Tb (see FIG. 2) of the input AC voltage Va is uniquely determined. Therefore, if the time T1 from the voltage zero point Pa of the input AC voltage Va to the output of the L level control signal Sx is known, the time T3 at which the control signal Sx should be raised to the H level is uniquely determined.

  Therefore, the CPU 5 calculates the time T3 at which the control signal Sx should be raised again based on the time T1 until the control signal Sx of L level is output and the time T2 of the half cycle of the input AC voltage Va. If the counter determines that the elapsed time has reached time T3, the control signal Sx is raised. Therefore, the signal level of the control signal Sx is synchronized with the input AC voltage Va of the commercial power supply 2. When the H level control signal Sx is output, the photocouplers 31 to 33 are turned on, the neon transformer 8 is deactivated, the input AC voltage Va is cut before the resonance circuit 30, and the resonance circuit 30 is turned on. There is no resonance, and the discharge lamp 3 is not supplied with the output voltage Vb.

Next, the operation of the discharge lamp control device 1 having the above configuration will be described.
First, when the commercial power source 2 is supplied, the control power source circuit 12 starts driving with the input AC voltage Va of the commercial power source 2 to supply power to the CPU 5, and the CPU 5 is started by the power source. The CPU 5 executes the control program of the ROM 6 and drives and controls the neon transformer 8 via the photocouplers 31 to 33 so that the discharge lamp 3 is lit (dimmed) and blinks with the pattern data written in the ROM 6. The pattern data here is data that determines how the discharge lamp 3 is turned on and blinking, that is, the brightness of the discharge lamp 3, the order of light, the number of blinks, the lighting time, and the like.

  Here, when the CPU 5 is activated, the control signal Sx is output so as to be synchronized with the input AC voltage Va of the commercial power source 2. At this time, when the zero-cross signal Sa is output from the zero-cross detection circuit 13 as the input AC voltage Va of the commercial power supply 2 rises, the H-level control signal is output from that point until the timing at which the L-level control signal Sx should be output. Sx is output. In this state, the photocouplers 31 to 33 are turned on, and the current supplied from the commercial power supply 2 is short-circuited by the photocouplers 31 to 33. Therefore, no current is supplied to the resonance circuit 30 and the output voltage Vb is not generated on the secondary side of the transformer 14.

  On the other hand, when the L-level control signal Sx is output after the time T <b> 1 has elapsed, the photocouplers 31 to 33 are turned off, and the current from the commercial power supply 2 flows to the resonance circuit 30. Then, the resonance circuit 30 is in a resonating state, whereby a high-frequency output voltage Vb is induced in the secondary winding 16, and the discharge lamp 3 is turned on by the high-voltage output voltage Vb. Then, the L level control signal Sx is repeatedly output, so that the discharge lamp 3 is lit with a luminance corresponding to the L level period width of the control signal Sx. For example, in the case of dimming control, this period width is By changing, the luminance of the discharge lamp 3 is adjusted.

  In this example, each discharge lamp 3 is turned on (dimmed) and blinked by on / off control of the photocouplers 31 to 33. Therefore, since control is not applied to the input AC voltage Va itself of the commercial power supply 2, it is not necessary to perform a process for cutting the input AC voltage Va. Therefore, switching loss does not occur, which contributes to energy saving. In particular, in this type of discharge lamp control device 1, a current of about 1 A flows from the commercial power source 2, so that when the switch itself is turned on / off, the loss is very large and the energy efficiency is not very good. Since there is no such a thing, energy saving is especially remarkable.

  When the control method of this example is used, the photocouplers 31 to 33 are arranged on the downstream side of the smoothing circuit 10, and control is performed on the downstream side of the smoothing circuit 10. For this reason, the discharge lamps 3 are turned on in response to a command from the CPU 5 without waiting for the smoothing circuit 10 to be charged. Therefore, when the CPU 5 outputs the control signal Sx at the H level, the output voltage Vb is immediately applied from the secondary side. As a result, the lighting response of each discharge lamp 3 is accelerated. Therefore, as shown in FIG. 2, the time lag between the H level output of the control signal Sx and the output of the output voltage Vb is reduced, the output time of the output voltage Vb is sufficiently secured, and the deterioration of the dimming performance is suppressed. The

  By the way, when the dimming control of the discharge lamp 3 is performed using the phase control described in the background art, the phase control applies control to the input AC voltage Va itself of the commercial power supply 2 for each transformer. A circuit (a filter circuit in this example) and a full-wave rectifier circuit are respectively disposed. Therefore, when phase control is used, it is necessary to prepare a protective circuit, a full-wave rectifier circuit, and the like for each neon transformer 8, which causes a problem that the discharge lamp control device 1 becomes large. Moreover, the device for performing phase control (the power supply control device shown in FIG. 6) and the neon transformer 8 exist as separate components, and wiring work for wiring each neon transformer 8 to the power supply control device is necessary. Therefore, there is a concern that the wiring work is troublesome.

  However, if dimming control is performed by on / off control of the photocouplers 31 to 33 as in this example, this control is configured to apply control to the voltage after full-wave rectification and smoothing. The filter circuit 7, the full wave rectifier circuit 9, the smoothing circuit 10, and the ripple capacitor 11 in the example can be shared among the plurality of neon transformers 8. Accordingly, the size of the discharge lamp control device 1 is reduced as compared with the case where the filter circuit 7 and the full-wave rectifier circuit 9 are prepared for each neon transformer 8. In addition, the sharing of the discharge lamp control device 1 becomes only the wiring for the commercial power supply 2 by this sharing, which leads to simplification of the wiring work.

According to the configuration of the above embodiment, the following effects can be obtained.
(1) Photocouplers 31 to 33 are provided between the CPU 5 and the neon transformer 8, and the photocouplers 31 to 33 are controlled to be turned on / off by a control signal Sx, so that each discharge lamp 3 is turned on (dimmed) and blinked. Accordingly, since the neon transformer 8 can be controlled without using the phase control described in the background art, it is not necessary to control the input AC voltage Va itself that has been performed at the time of phase control. , Energy saving can be achieved.

  (2) Photocouplers 31 to 33 are disposed on the downstream side of the smoothing circuit 10, and on / off control of the photocouplers 31 to 33 is performed on the downstream side of the smoothing circuit 10. For this reason, the discharge lamps 3 are turned on in response to a command from the CPU 5 without waiting for the smoothing circuit 10 to be charged. Therefore, when the CPU 5 outputs the control signal Sx of L level, the output voltage Vb is immediately applied from the secondary side. As a result, the lighting response of each discharge lamp 3 can be accelerated. Therefore, the time lag between the L level output of the control signal Sx and the output of the output voltage Vb is reduced, the output time of the output voltage Vb can be secured sufficiently, and sufficient dimming performance that does not bother flickering is obtained. Can be secured. Note that this is also true for the electrolytic capacitor 23. If the photocouplers 31 to 33 are arranged downstream of both the smoothing circuit 10 and the electrolytic capacitor 23, the time lag is further reduced and high super performance is ensured. be able to.

  (3) If dimming control is performed by on / off control of the photocouplers 31 to 33, this control is configured to apply control to the voltage after full-wave rectification and smoothing. The wave rectifier circuit 9, the smoothing circuit 10, and the ripple capacitor 11 can be shared among the plurality of neon transformers 8. Therefore, the discharge lamp control device 1 can be reduced in size as compared with the case where the filter circuit 7 and the full-wave rectifier circuit 9 are prepared for each neon transformer 8. In addition, the sharing of the discharge lamp control device 1 becomes only the wiring for the commercial power supply 2 by this sharing, and the wiring work can be simplified.

  (4) Since the photocouplers 31 to 33 are used to control the neon transformer 8 by the CPU 5, the CPU 5 and the neon transformer 8 have a circuit configuration that is electrically separated. Therefore, for example, even if an overcurrent flows to the neon transformer 8 side due to a failure or the like, it does not flow into the CPU 5, so that it is difficult for the CPU 5 to be destroyed due to the overcurrent flow.

  (5) The discharge lamp control device 1 is unitized by accommodating various circuits (elements) constituting the discharge lamp control device 1 in one case 4. Therefore, compared to the case where various circuits exist as separate devices, attachment work, wiring work, carrying, etc. can be performed easily, and convenience can be improved.

In addition, you may change the said embodiment not only to the said structure but to the following aspects.
The circuit configuration shown in FIG. 5 may be used for the neon transformer 8 circuit. That is, the transistor 41 is connected to both ends of the Zener diode 24, the resistor 42 and the light receiving element 31b (32b, 33b) of the photocoupler 31 (32, 33) are connected in series between the resistor 22a and GND, and the resistor 42 The circuit configuration may be such that the midpoint of the light receiving element 31b (32b, 33b) is connected to the base terminal of the transistor 41.

  The discharge lamp control device 1 is not limited to a configuration in which a high voltage is output from the secondary side by resonating in a self-excited manner with the feedback winding 29. For example, the first FET 19 and the second FET 20 are controlled to be turned on / off by the CPU 5 so that a high voltage is induced on the secondary side by the mutual induction action.

  The connection position of the light receiving elements 31 b to 33 b of the photocouplers 31 to 33 is not limited to the upstream side of both ends of the Zener diode 24. For example, it may be between the intermediate tap of the primary winding 15 and the cathode terminal of the diode 27, or between the output terminal of the full-wave rectifier circuit 9 and the input terminal of the inductor 18.

  The filter circuit 7, the full wave rectifier circuit 9, the smoothing circuit 10, and the ripple capacitor 11 are not necessarily shared by the neon transformer 8. For example, only the filter circuit 7 may be shared, or the filter circuit 7 and the full-wave rectifier circuit 9 may be shared.

  The switching element is not limited to the photocouplers 31 to 33, and other elements such as FETs and MOSFETs may be used. The switching element is not limited to this type of transistor, and may be a contact type switch using an electromagnetic solenoid, for example.

-The power source is not limited to the commercial power source 2, and other power sources such as a storage battery may be used. Further, the power source is not limited to supplying an AC voltage, and may be replaced with a DC voltage.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.

  (1) In Claim 1, a primary winding of the transformer having an intermediate tap is connected in parallel between input terminals of a pair of resonant second switching elements, and the primary windings are different from each other. A mutual induction circuit in which the second switching elements are alternately turned on so that a magnetic field of a direction is alternately generated, and the control circuit performs on / off control of the switching elements based on the control signal, thereby the input The application of the input voltage to the transformer is controlled so that the mutual induction circuit can be operated by voltage.

  (2) In any one of Claims 2-6, each said 2nd switching element is equipped with the constant voltage supply circuit which supplies the said input voltage as a voltage of a fixed value, The said switching element is the said constant voltage supply It is connected in parallel to both ends on the upstream side of the circuit.

  (3) In any one of Claims 1-6, the said transformer and the said switching element are connected in the state which made the group, and the transformer unit which consists of the said transformer and the switching element which made the group at least is plural. I have.

  (4) In any one of Claims 1-6, the said transformer and the said switching element are connected in the state which made the group, and the transformer unit which consists of the said transformer and the switching element which made the group at least is plural. And at least a plurality of the converter units and the control circuit are unitized by being accommodated in the same case.

  (5) In any one of Claims 1-6, the said transformer and the said switching element are connected in the state which made the group, and the transformer unit which consists of the said transformer and the switching element which made the group at least is plural. The filter circuit is shared among the plurality of transformer units by connecting the plurality of transformer units in parallel to a filter circuit for removing noise of the input voltage upstream of the rectifier circuit. Yes.

  (6) In any one of Claims 1-6, the said control circuit controls application of the said input voltage to the said transformer by carrying out on-off control of the said switching element with the control signal synchronized with the said input voltage. To do. In this case, if a capacitor is used in the smoothing circuit, for example, the capacitor capacity can be reduced.

The block diagram which shows schematic structure of the discharge lamp control apparatus in one Embodiment. The wave form diagram which shows the relationship between an input alternating voltage, a control signal, and an output voltage. The circuit diagram which shows the electric constitution of a discharge lamp control apparatus. The circuit diagram which shows the electric constitution of a neon transformer. The circuit diagram which shows the electric constitution of the neon transformer in another example. The wave form diagram which shows the relationship between the input voltage and output voltage in the past. The block diagram which shows the outline of a discharge lamp control apparatus similarly.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Discharge lamp control apparatus, 2 ... Commercial power supply as a power supply, 3 ... Discharge lamp, 5 ... CPU as a control circuit, 8 ... Neon transformer as a transformer unit, 9 ... Full wave rectifier circuit, 10 ... Smoothing circuit, DESCRIPTION OF SYMBOLS 14 ... Transformer, 15 ... Primary winding, 17 ... Resonance capacitor, 19 ... 1st FET which comprises a 2nd switching element, 20 ... 2nd FET which comprises a 2nd switching element, 23 ... Electrolysis as a stable voltage supply circuit Capacitor, 29 ... Feedback winding, 30 ... Resonant circuit, 31-33 ... Photocoupler as switching element, 31a-33a ... Light emitting element, 31b-33b ... Light receiving element, Va ... Input AC voltage as input voltage, Sx ... Control signal.

Claims (6)

The input voltage input from the power source is rectified by a rectifier circuit, the input voltage smoothed by a smoothing circuit after rectification is transformed to a high voltage by a transformer, and a discharge lamp connected to the secondary side of the transformer is connected to the high voltage In the discharge lamp control device that is lit or blinks depending on the voltage,
A switching element connected between the rectifier circuit and the transformer to turn on / off application of the input voltage after rectification to the transformer;
A discharge lamp control device comprising: a control circuit that controls application of the input voltage to the transformer by controlling on / off of the switching element. A primary winding of the transformer having an intermediate tap is connected in parallel between the input terminals of the pair of resonant second switching elements, and a resonant capacitor is also connected in parallel between the input terminals of the second switching elements. And having both ends of the feedback winding of the transformer connected to the control terminal of the second switching element to alternately induce the second switching element at the resonance frequency of the primary winding of the transformer. With a circuit,
The control circuit controls the application of the input voltage to the transformer so that the resonance circuit can resonate by the input voltage by performing on / off control of the switching element based on a control signal. The discharge lamp control device according to claim 1.   The discharge lamp control device according to claim 1, wherein the switching element is connected to a downstream side of the smoothing circuit. A stable voltage supply circuit for supplying the input voltage as a stable voltage to each of the second switching elements;
The discharge lamp control device according to claim 2, wherein the switching element is connected to a downstream side of the stable voltage supply circuit.   The transformer and the switching element are connected in a set state, and are provided with a plurality of transformer units including at least the transformer and the switching element, and the rectifier circuit includes a plurality of the transformer units in parallel. The discharge lamp control device according to any one of claims 1 to 4, wherein the rectifier circuit is shared among the plurality of transformer units by being connected to a power source.   The switching element is an optical sensor comprising a light emitting element connected to the control circuit side and a light receiving element capable of receiving light from the light emitting element and connected to the transformer side. The discharge lamp control device according to any one of claims 1 to 5, wherein

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