JP2012064410A - Lighting device and lighting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device and lighting fixture whose size avoids enlarging, although they can operate in accordance with the length of an off period.SOLUTION: The lighting device and fixture comprise a timer capacitor C3 to be charged only during an on period for which electric power is applied to a lighting circuit for lighting a light source and the light source is lit and a time constant circuit 6 having a discharge resistor R2 connected between both ends of the timer capacitor C3. A control circuit 3 for controlling the lighting circuit differentiates the control content during the on period in response to whether or not the voltage Vc across the timer capacitor C3 at the start point of the on period is higher than a prescribed changing voltage. The timer capacitor C3, assuming the case where an oscillator and counter are used in timing the length of an off period, can have less capacity and a smaller size than the capacitor required for the power supply of the oscillator and counter during the off period. In short, enlarging in size is avoided as compared to the case of using the oscillator and counter in timing the length of the off period.

Description

  The present invention relates to a lighting device and a lighting fixture.

  Conventionally, the operation when the light source is turned on next is determined according to the length of time during which the power supply from the external power supply is turned off and the light source is turned off (hereinafter referred to as “light-off period”). There is provided a lighting device for switching (see, for example, Patent Document 1).

  Specifically, if the length of the extinguishing period is longer than a predetermined time, the light source is turned on with rated power, and if the length of the extinguishing period is shorter than the predetermined time, the light source is turned on with preset power.

Japanese Patent No. 3508175

  Here, when the length of the extinguishing period is measured using an oscillator and a counter that are generally included in a microcomputer used for control, power is supplied to the oscillator and the counter for at least the predetermined time after the power supply is turned off. Need to be supplied. That is, it is necessary to use a capacitor or the like having a relatively large capacitance in order to store power necessary for the operation of the oscillator and the counter for at least the predetermined time, which may cause an increase in size.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a lighting device and a lighting fixture that can be operated according to the length of the extinguishing period but can be prevented from being enlarged. is there.

  The lighting device of the present invention includes a lighting circuit that turns on a light source by power converted from power input from an external power source, a control circuit that controls the lighting circuit, and power that is input from the power source to the lighting circuit. A control power supply circuit that generates power for operating the control circuit only during a period in which power is input from the power supply to the lighting circuit, and the power supply From at least the power source to the lighting circuit, and a timing resistor that is charged only during a period in which power is input from the power source to the lighting circuit, and a discharging resistor connected between both ends of the timing capacitor. A time constant circuit that discharges the time-measurement capacitor through the discharging resistor during a period in which no input is made, and the control circuit supplies the lighting circuit from the power source. Voltage across the timing capacitor is characterized in that to vary the contents of control for the subsequent the lighting circuit in accordance with whether or not higher than a predetermined switching voltage at the input of the power is started.

  In this lighting device, it is desirable to include a power supply capacitor that is charged by the control power supply circuit and serves as a power supply for the control circuit.

  Moreover, the lighting fixture of this invention is equipped with one of said lighting apparatuses, and the fixture main body holding the said lighting device, It is characterized by the above-mentioned.

  According to the present invention, the time constant circuit enables control according to the length of the extinguishing period when power is not input from the power source to the lighting circuit. In addition, when the oscillator and the counter are used to measure the length of the extinguishing period, a time-capacitance capacitor having a smaller capacitance and smaller than a capacitor required as a power source for the oscillator and the counter during the extinguishing period can be used. That is, an increase in size can be avoided as compared with the case where an oscillator and a counter are used for measuring the length of the extinguishing period.

It is a circuit block diagram which shows the principal part of embodiment of this invention. It is a circuit block diagram which shows the same as the above. It is explanatory drawing which shows an example of an operation | movement same as the above.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In the present embodiment, as shown in FIG. 2, a rectifier circuit 11 formed of, for example, a diode bridge that rectifies AC power input from an external AC power supply 7, and an output of the rectifier circuit 11 is smoothed and boosted. A well-known boost converter (boost chopper circuit) 12 that generates DC power of voltage, and an inverter circuit that turns on the discharge lamp 21 by converting the DC power output from the boost converter 12 into AC power and outputting it to the discharge lamp 21 13. The boost converter 12 has a capacitor C1 connected between the output terminals, and operates so as to maintain the voltage (that is, output voltage) Vdc across the capacitor C1 at a predetermined target voltage Vdc1 as shown in FIG.

  Furthermore, the present embodiment includes a control circuit 3 configured by a microcomputer that controls the inverter circuit 13, a control power supply circuit 4 that generates power necessary for the operation of the control circuit 3 by stepping down the output of the boost converter 12, And a capacitor C <b> 2 (hereinafter referred to as “power supply capacitor”) that is charged by the control power supply circuit 4 and serves as a power supply for the control circuit 3. The control power supply circuit 4 is a circuit in which, for example, a capacitor between output terminals is omitted in a known buck converter (step-down chopper circuit). The control power supply circuit 4 monitors the output voltage Vdc of the boost converter 12 and supplies power from the AC power supply 7 to the rectifier circuit 11 only during a period in which the output voltage Vdc of the boost converter 12 is equal to or higher than a predetermined operating voltage Vdc2. Is output and power is output to the power supply capacitor C2. Further, the control power supply circuit 4 maintains the voltage Vdd across the power supply capacitor C2 at a predetermined control voltage Vdd1 by known feedback control during power output. The control voltage Vdd1 is made somewhat higher than the minimum voltage (hereinafter referred to as “essential voltage”) Vdd2 required for the operation of the control circuit 3. As the capacitor C1 of the boost converter 12 and the power supply capacitor C2, for example, an aluminum electrolytic capacitor can be used.

  Further, the present embodiment includes a light emitting diode 22. The light emitting diode 22 is turned on by being supplied with the output of the control power supply circuit 4 via the control circuit 3, for example. The control circuit 3 includes a switching element (not shown) inserted in a power supply path from the control power supply circuit 4 to the light emitting diode 22. By turning on / off the switching element, the light emitting diode 22 is turned on / off. Control. That is, the light sources that are turned on according to the present embodiment are the discharge lamp 21 and the light emitting diode 22, and the rectifier circuit 11, the boost converter 12, the inverter circuit 13, and the control power supply circuit 4 constitute a lighting circuit.

  Further, when the input of power from the AC power supply 7 to the rectifier circuit 11 is started, the control circuit 3 has elapsed time (hereinafter referred to as “OFF”) after the input of power from the AC power supply 7 to the rectifier circuit 11 is stopped. The operation is switched according to time. In order to enable the above-described operation, the present embodiment includes a power supply detection circuit 5 that detects input of power from the AC power supply 7 to the rectifier circuit 11 and a time constant circuit 6 for counting off time. .

  The power supply detection circuit 5 is connected to the cathodes of two diodes Da and Db each having an anode connected to one input terminal of the rectifier circuit 11. The power supply detection circuit 5 determines whether or not AC power is input to the rectifier circuit 11 based on the inputs from the two diodes Da and Db, and the input voltage to the control circuit 3 according to the determination result. Switch. Since the power supply detection circuit 5 as described above can be realized by a known technique, detailed illustration and description thereof are omitted.

  As shown in FIG. 1, the time constant circuit 6 is a parallel circuit of a capacitor (hereinafter referred to as “timer capacitor”) C3 and a discharge resistor (hereinafter referred to as “discharge resistor”) R2. Is provided. The control circuit 3 has a charging terminal 31 for outputting a voltage for charging the time measuring capacitor C3. The charging terminal 31 is connected to the parallel circuit through a series circuit of a diode D1 for preventing backflow and a resistor R1. It is connected to one end. The other end of the parallel circuit is connected to the ground.

  Further, the control circuit 3 has a timing input terminal 32 to which the voltage Vc across the clock capacitor C3 is input, and an input switching terminal 33 for switching on and off the input of the voltage across the clock input terminal 32. The timing input terminal 32 is connected to one end of the parallel circuit via a PNP-type first transistor Q1. The base of the first transistor Q1 is connected to the ground via an NPN-type second transistor Q2, and the input switching terminal 33 is connected to the base of the second transistor Q2.

  The operation of this embodiment will be described below.

  The control circuit 3 operates only during a period (hereinafter referred to as “control period”) Tc1 in which the voltage Vdd across the power supply capacitor C2 is equal to or higher than the essential voltage Vdd2, and stops during the other period Tc0. Further, during the control period Tc1, and during the period (hereinafter referred to as “lighting period”) Tp1 in which it is determined by the power feeding detection circuit 5 that AC power is input to the rectifier circuit 11, the control is performed. The circuit 3 turns off the light emitting diode 22 and operates the inverter circuit 13 to turn on the discharge lamp 21 or turns on the discharge lamp 21 while turning off the discharge lamp 21 and turns on the light emitting diode 22. Either of these operations is performed alternatively. Further, the control circuit 3 charges the timer capacitor C3 to the predetermined voltage Vc1 only by setting the output voltage V31 of the charging terminal 31 to the H level only during the lighting period Tp1. The period Tcc1 in which the time measuring capacitor C3 is charged substantially coincides with the lighting period Tp1, and the period Tcc0 in which the time measuring capacitor C3 is discharged substantially coincides with the extinguishing period Tp0.

  When the input of AC power to the rectifier circuit 11 is stopped, the control circuit 3 turns off the one that is lit between the discharge lamp 21 and the light emitting diode 22 based on the change in the output of the power supply detection circuit 5. At the same time, the output voltage V31 of the charging terminal 31 is set to the L level to stop the charging of the time measuring capacitor C3. Thus, during the period when both the discharge lamp 21 and the light emitting diode 22 are extinguished (hereinafter referred to as “extinguishing period”) Tp0, the voltage Vc across the clock capacitor C3 is equal to the voltage across the clock capacitor C3. It decreases with a time constant corresponding to the capacitance and the resistance value of the discharging resistor R2.

  Next, when the input of AC power to the rectifier circuit 11 is resumed and the voltage Vdd across the power supply capacitor C2 reaches the essential voltage Vdd2, the control circuit 3 is connected to the input switching terminal 33 that is normally maintained at the L level. The output voltage V33 is temporarily set to the H level. Then, the first transistor Q1 is turned on, and the voltage across the clock capacitor C3 (hereinafter referred to as “time clock voltage”) Vc is input to the time input terminal 32. The timed voltage Vc at this time becomes lower as the immediately preceding extinguishing period Tp0 is longer. The control circuit 3 compares the timekeeping voltage Vc input to the timekeeping input terminal 32 with a predetermined switching voltage Vc2, and determines whether to perform the discharge lamp lighting operation or the light emitting diode lighting operation thereafter according to the comparison result. decide. Specifically, the control circuit 3 stores a non-volatile memory (not shown) that stores which one of the discharge lamp lighting operation and the light emitting diode lighting operation was performed before the input of the AC power to the rectifying circuit 11 is stopped. Z). Then, the control circuit 3 performs an operation different from the operation stored in the non-volatile memory after that if the clock voltage Vc is equal to or higher than the switching voltage Vc2 at the time of the comparison, and at an appropriate timing. Rewrite the above nonvolatile memory. On the other hand, if the measured voltage Vc is less than the switching voltage Vc2 at the time of the comparison, the control circuit 3 performs the operation stored in the nonvolatile memory thereafter. In the example of FIG. 3, in the second lighting period Tp1, the control circuit 3 performs an operation different from that of the first lighting period Tp1 because the timing voltage Vc is equal to or higher than the switching voltage Vc2 at the start. Further, during the third lighting period Tp1, the control circuit 3 performs the same operation as the second lighting period Tp1 because the clock voltage Vc is less than the switching voltage Vc2 at the start. For example, when the control circuit 3 performs the discharge lamp lighting operation before the input of the AC power to the rectifier circuit 11 is stopped, if the voltage Vc across the clock capacitor C3 is equal to or higher than the switching voltage Vc2, Performs a light-emitting diode lighting operation. If the timekeeping voltage Vc is less than the switching voltage Vc2, the discharge lamp lighting operation is performed thereafter. The switching voltage Vc2 is, for example, the voltage across the clock capacitor C3 when the length of the extinguishing period Tp0 is 2 seconds. In this case, different operations are performed before and after the turn-off period Tp0 whose length is less than 2 seconds, and common operations are performed before and after the turn-off period Tp0 whose length is 2 seconds or more.

  According to the above configuration, the time constant circuit 6 enables control according to the length of the extinguishing period Tp0.

  Here, in the present embodiment, since the control circuit 3 uses the power supply capacitor C2 as a power supply, the voltage across the power supply capacitor C2 is maintained even after the operation of the control power supply circuit 4 is stopped with the start of the turn-off period Tp0. The control circuit 3 is operable during the time until Vdd drops to the essential voltage Vdd2 (hereinafter referred to as “operation maintaining time”). However, in this embodiment, the length of the light extinction period Tp0 is measured by the time constant circuit 6 instead of the control circuit 3, so that the operation maintaining time is the length of the light extinction period Tp0 (ie, the operation is switched). The time until the time-measurement voltage Vc reaches the switching voltage Vc2 can be made shorter (for example, 0.2 seconds). That is, it is possible to use a small capacitor having a smaller capacitance as the power supply capacitor C2 than when using the oscillator and counter (not shown) in the control circuit 3 to measure the length of the extinguishing period Tp0. The size and shape of the power supply capacitor C2 and the time constant circuit 6 in this embodiment are smaller than the size and shape of the power supply capacitor C2 when the oscillator and the counter are used to measure the length of the turn-off period Tp0. Is possible. That is, an increase in size can be avoided as compared with the case where an oscillator and a counter are used for measuring the length of the extinguishing period Tp0.

  The lighting device described above can be held by a suitably shaped fixture body to constitute a lighting fixture (not shown).

  The control according to the length of the extinguishing period Tp0 is not limited to the switching of the light sources 21 and 22 to be lit as described above. For example, the light of the light source such as the discharge lamp 21 according to the length of the extinguishing period Tp0. Control of switching the output is also possible.

3 Control circuit 4 Control power supply circuit 6 Time constant circuit 7 AC power supply (external power supply)
11 Rectifier circuit (part of lighting circuit)
12 Boost converter (part of lighting circuit)
13 Inverter circuit (part of lighting circuit)
21 Discharge lamp (light source)
22 Light-emitting diode (light source)
C2 Power supply capacitor C3 Timing capacitor R2 Discharge resistor

Claims (3)

A lighting circuit that turns on the light source with power converted from power input from an external power source;
A control circuit for controlling the lighting circuit;
In order to determine whether or not power is input from the power source to the lighting circuit, and to operate the control circuit only during a period when it is determined that power is input from the power source to the lighting circuit A control power supply circuit for generating
At least from the power source to the lighting circuit, the capacitor includes a timing capacitor that is charged only during a period in which power is input from the power source to the lighting circuit, and a discharging resistor connected between both ends of the timing capacitor. A time constant circuit for discharging the timer capacitor through the discharging resistor during a period in which power is not input,
The control circuit determines whether the voltage across the clock capacitor is higher than a predetermined switching voltage at the time when input of power from the power source to the lighting circuit is started. A lighting device characterized in that the contents of control are different.   The lighting device according to claim 1, further comprising a power supply capacitor that is charged by the control power supply circuit and serves as a power supply for the control circuit.   A lighting fixture comprising: the lighting device according to claim 1 or 2; and a fixture main body that holds the lighting device.

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