JP2014158329A - Power supply device and illuminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC power supply device in which malfunction due to variation and resetting of the voltage of a commercial power supply is prevented, and to provide an LED lighting device.SOLUTION: A DC voltage conversion circuit 21 converts an AC voltage from a commercial AC power supply (e) into a DC voltage. A constant current circuit 22 is supplied with power by the DC voltage conversion circuit 21, and outputs a constant current to an LED 14. Power supply detection means 23 detects any one of the voltage V1 of the commercial AC power supply (e) or an electrical quantity corresponding to the voltage V1. DC voltage detection means 24 detects any one of the output voltage from the DC voltage conversion circuit 21 or an electrical quantity corresponding to the voltage V2. Control means 25 reduces the output current from the constant current circuit 22, when the state where the detection value of the power supply detection means 23 is less than a predetermined value sustains less than a predetermined time, and the detection value of the DC voltage detection means 24 is less than a predetermined time.

Description

  Embodiments described herein relate generally to a power supply apparatus having a constant current circuit that outputs a constant current to a load, and an illumination apparatus including the power supply apparatus.

  Conventionally, in an LED lighting device, for example, an AC voltage from an external power source such as a commercial AC power source is rectified and constant by a constant voltage circuit such as a step-up chopper circuit, and a constant voltage operated by this constant voltage is used. There is a configuration in which a constant current is supplied to a series circuit of LEDs by a current circuit to light these LEDs.

  In such a configuration, for example, when the fluctuation of the external power supply voltage occurs, the output current from the constant current circuit is changed, and when the external power supply is restored, the output current from the constant current circuit is restored. ing.

JP 2011-9383 A

  However, fluctuations in the external power supply voltage within a predetermined short period of time usually require time for determination of fluctuations and are not easily detected with certainty, and may be ignored for control purposes. Therefore, when the external power supply voltage fluctuates within this predetermined short period of time, the output voltage from the constant voltage circuit fluctuates so that malfunctions such as fluctuation (overcontrol) of the output current from the constant current circuit do not occur. It is desirable to make it. In particular, when the external power supply voltage drops for a short time and then recovers and rises, it is desirable to prevent the output current from the constant current circuit from becoming excessive.

  The problem to be solved by the present invention is to provide a power supply apparatus that prevents malfunction caused by fluctuation and recovery of the voltage of the external power supply, and a lighting apparatus including the power supply apparatus.

  The power supply device of the embodiment includes a DC voltage conversion circuit, a constant current circuit, a power supply voltage detection unit, a DC voltage detection unit, and a control unit. The DC voltage conversion circuit converts an AC voltage from an external power source into a DC voltage. The constant current circuit is fed by a DC voltage conversion circuit and outputs a constant current to the load. The power supply voltage detecting means detects either the voltage of the external power supply or an electrical quantity corresponding to this voltage. The direct-current voltage detection means detects either the output voltage of the direct-current voltage conversion circuit or an electrical quantity corresponding to the output voltage. The control means reduces the output current of the constant current circuit when the detection value of the power supply voltage detection means is less than a predetermined value for less than a predetermined time and the detection value of the DC voltage detection means is less than a predetermined value.

  According to the present invention, the output current of the constant current circuit is reduced when the detection value of the power supply voltage detection means is less than the predetermined value for less than the predetermined time and the detection value of the DC voltage detection means is less than the predetermined value. By doing so, it can be expected to prevent malfunction caused by fluctuation and recovery of the voltage of the external power supply.

It is a block diagram which shows the power supply device of 1st Embodiment. It is a block diagram which shows the power supply device of 2nd Embodiment. It is a block diagram which shows the power supply device of 3rd Embodiment.

  The configuration of the first embodiment will be described below with reference to the drawings.

  In FIG. 1, 11 indicates an LED lighting device as a lighting device. The LED lighting device 11 includes a DC power supply device 12 as a power supply device electrically connected to, for example, a commercial AC power source e, which is an external power source, And a module 15 having a series circuit of LEDs 14 as light emitting elements as a plurality of loads that can be attached to and detached from the DC power supply device 12 through contacts 13 and 13. The LED lighting device 11 is configured to light the LED 14 by supplying a constant current from the DC power supply device 12 to the LED 14 (module 15). Note that the module 15 may be connected to the DC power supply device 12 alone, or a plurality of modules 15 may be connected in parallel. Further, the module 15 may be formed of a light emitting element such as an organic EL instead of the LED 14, for example.

  Then, the DC power supply device 12 generates a DC voltage conversion circuit 21, a constant current circuit 22 that operates by feeding from the DC voltage conversion circuit 21, and a voltage V1 that is an electrical quantity corresponding to the voltage of the commercial AC power supply e. A power supply voltage detecting means 23 for detecting, a DC voltage detecting means 24 for detecting the output voltage V2 of the DC voltage converting circuit 21, and a control means 25 for controlling the operation of the constant current circuit 22 are provided.

  The DC voltage conversion circuit 21 includes, for example, a high frequency blocking filter circuit 31 connected to a commercial AC power source e, a rectifier circuit 32 connected to the output side of the filter circuit 31 to rectify an AC voltage (full wave), A constant voltage circuit 33 connected to the output side of the rectifier circuit 32 and a smoothing capacitor 34 as a smoothing means for smoothing the output voltage of the constant voltage circuit 33 are provided.

  The filter circuit 31 is composed of, for example, a capacitor and a common mode choke.

  Further, the rectifier circuit 32 is configured by, for example, a bridge diode.

  The constant voltage circuit 33 is, for example, a step-up chopper circuit or a step-down chopper circuit provided with a switching element, and is configured to step up or step down the voltage rectified by the rectifier circuit 32 to obtain a constant voltage. .

  The smoothing capacitor 34 is a capacitive element such as an electrolytic capacitor, for example, and smoothes the output voltage of the constant voltage circuit 33 and outputs a predetermined DC constant voltage to the constant current circuit 22.

  The constant current circuit 22 includes a chopper circuit, for example, and outputs a DC constant current to the LED 14 (module 15). Further, a capacitor 35 is connected to the output side of the constant current circuit 22 in parallel with the LED 14 (module 15).

  Further, the power supply voltage detection means 23 detects the voltage V1 corresponding to the voltage of the commercial AC power supply e by detecting the voltage across the rectifier circuit 32, for example, and constantly outputs the detected voltage V1 to the control means 25 It is possible. That is, the control means 25 monitors the voltage V1 via the power supply voltage detection means 23. The power supply voltage detection means 23 may directly detect the voltage V1 or may detect an electrical quantity corresponding to the voltage V1. Therefore, hereinafter, the voltage V1 detected by the power supply voltage detection means 23 or the detection value by the power supply voltage detection means 23 shall refer to the voltage V1 or an electrical quantity corresponding to this voltage V1.

  Further, the DC voltage detection means 24 detects the output voltage V2 of the DC voltage conversion circuit 21 by detecting the voltage across the constant voltage circuit 33, that is, the voltage across the smoothing capacitor 34, for example, and this detected output The voltage V2 can always be output to the control means 25. That is, the control means 25 monitors the output voltage V2 via the DC voltage detection means 24. The DC voltage detection means 24 may directly detect the output voltage V2, or may detect an electrical quantity corresponding to the output voltage V2. Therefore, hereinafter, the output voltage V2 detected by the DC voltage detection means 24 or the detection value by the DC voltage detection means 24 is assumed to indicate the output voltage V2 or an electrical quantity corresponding to the output voltage V2.

  Further, the control means 25 is, for example, a microcomputer or the like, has a built-in storage means (memory) or the like, and controls the switching element of the constant current circuit 22 such as a chopper circuit by PWM control or the like. The output current is controlled to a predetermined constant current. Further, the control means 25 sets the detection value of the power supply voltage detection means 23 and the detection value of the DC voltage detection means 24 to, for example, at least 1/2 or less of the cycle of the AC voltage (AC current) of the commercial AC power supply e. Acquired sequentially in cycles.

  Then, when the power is turned on, for example, the control means 25 gradually increases the output current from the constant current circuit 22 to make the LED 14 fade-in, and the voltage V1 detected by the power supply voltage detection means 23, and The operation of the constant current circuit 22 is controlled based on the output voltage V2 detected by the DC voltage detecting means 24.

  Specifically, the control means 25 is configured such that the detected value of the power supply voltage detecting means 23 is less than a predetermined value TH1, for a predetermined time T1, for example, a predetermined cycle or more of the AC voltage (AC current) of the commercial AC power supply e, or When the voltage (current) obtained by rectifying the AC power source e continues for a predetermined cycle or more, the output current of the constant current circuit 22 is reduced. That is, when the voltage (voltage V1) of the commercial AC power source e has decreased for a predetermined time T1 or longer, the control means 25 determines that the commercial AC power source e is abnormal and the output current of the constant current circuit 22 is determined. Reduce.

  Further, the control means 25 is configured such that the detected value of the power supply voltage detecting means 23 is less than a predetermined value TH1, for a predetermined time T1, for example, less than a predetermined cycle of the AC voltage (AC current) of the commercial AC power supply e, or the commercial AC power supply If the detected value of the DC voltage detecting means 24 is less than the predetermined value TH2 when the voltage (current) obtained by rectifying e is less than a predetermined cycle, the output current of the constant current circuit 22 is reduced. That is, even when the voltage (voltage V1) of the commercial AC power supply e drops and recovers only for a short time (<predetermined time T1), the output voltage V2 of the DC voltage conversion circuit 21 serving as the power supply of the constant current circuit 22 is constant current. When there is a possibility of affecting the degree to which the output current from the circuit 22 is lowered, it is determined that the DC voltage conversion circuit 21 is abnormal, and the output current of the constant current circuit 22 is reduced.

  The reduction of the output current includes the meaning of reducing the output current from the constant current circuit 22 to 0, that is, stopping the output from the constant current circuit 22 (stopping the operation of the constant current circuit 22). .

  As a result, it is possible to prevent malfunction caused by fluctuation and recovery of the voltage (voltage V1) of the commercial AC power source e.

  That is, the fluctuation of the voltage (voltage V1) of the commercial AC power source e as described above within a predetermined short time (less than the predetermined time T1) is not easy to reliably detect due to the time required for determining the fluctuation. Therefore, it may be ignored for control purposes. On the other hand, increasing the capacity of the smoothing capacitor 34 can suppress fluctuations in the voltage (voltage V1) of the commercial AC power source e as described above for a short time (less than a predetermined time T1). Increasing the size increases the size of the smoothing capacitor 34, which increases the cost as well as the mounting space. Therefore, in the present embodiment, it is possible to prevent malfunction (abnormal operation) due to short-time fluctuation and return of the voltage (voltage V1) of the commercial AC power source e without increasing the size of the smoothing capacitor 34. Cost increase can be prevented.

  Further, the control means 25 may be provided with a plurality of predetermined values TH2 for comparing the detection values of the DC voltage detection means 24, and the output current of the constant current circuit 22 may be reduced stepwise. That is, the control means 25 determines that the detected value of the power supply voltage detection means 23 is less than the predetermined value TH1, for a predetermined time T1, for example, less than a predetermined cycle of the AC voltage (AC current) of the commercial AC power supply e, or the commercial AC power supply e When the detected value of the DC voltage detecting means 24 is less than the first predetermined value TH2a when the voltage (current) rectified is less than a predetermined cycle, the output current of the constant current circuit 22 is reduced, and this output current When the detected value of the DC voltage detecting means 24 becomes less than the second predetermined value TH2b, which is smaller than the first predetermined value TH2a, in a state where the voltage is lowered, the output of the constant current circuit 22 is stopped. As a result, fluctuation and recovery of the voltage (voltage V1) of the commercial AC power source e can be detected more accurately and reliably, and malfunction caused by this fluctuation and recovery can be prevented more reliably.

  Each of the above controls is determined by comparing the detection values of the power supply voltage detection means 23 and the DC voltage detection means 24 with the respective predetermined values by a predetermined number of times to reduce (stop) the output of the constant current circuit 22. This may be performed when the number of times continues for a predetermined number of times, or when the ratio of the number of times determined to reduce (stop) the output of the constant current circuit 22 is equal to or greater than a predetermined value.

  Further, the control means 25 reduces the output current of the constant current circuit 22 (except for stoppage), and then when the detection value of the power supply voltage detection means 23 returns to a predetermined value TH1 or more, for example, equivalent to when power is turned on. The output current of the constant current circuit 22 may be restored by control, or the output current of the constant current circuit 22 may be increased stepwise to restore. When the output current of the constant current circuit 22 is restored by the same control as when the power is turned on, for example, the output current of the constant current circuit 22 is gradually increased from 0 or a value close to 0 to turn on the LED 14 in a fade-in manner. By doing so, the LED 14 can be gradually returned to the original lighting state, and a sense of incongruity is unlikely to occur. In addition, when returning the output current of the constant current circuit 22 by increasing it step by step, the output current of the constant current circuit 22 is increased from a value close to the output current in the original lighting state, thereby returning the original lighting. It is possible to quickly return to the state.

  Next, a second embodiment will be described with reference to FIG. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, the DC power supply device 12 of the first embodiment includes current detection means 36 for detecting an output current from the constant current circuit 22, that is, a load current I.

  This current detecting means 36 includes an impedance element such as a resistor connected between, for example, the constant current circuit 22 and the LED 14 (contact 13 of the module 15), and can detect and output the detected load current I to the control means 25 at all times. It has become. That is, the control means 25 monitors the load current I through the current detection means 36. The current detection means 36 may directly detect the load current I or may detect an electrical quantity corresponding to the load current I. Therefore, hereinafter, the load current I detected by the current detection means 36 or the detection value by the current detection means 36 refers to the load current I or an electrical quantity corresponding to the load current I.

  Further, the control means 25 uses the detection value of the power supply voltage detection means 23, the detection value of the DC voltage detection means 24, and the detection value of the current detection means 36, for example, a predetermined AC voltage (AC current) of the commercial AC power supply e. It is sequentially acquired at a predetermined timing such as every cycle or every predetermined cycle of a voltage (current) obtained by rectifying the commercial AC power source e. The control means 25 is a constant current circuit based on the voltage V1 detected by the power supply voltage detection means 23, the output voltage V2 detected by the DC voltage detection means 24, and the load current I detected by the current detection means 36. 22 operations are controlled.

  Specifically, the control means 25 indicates that the detected value of the power supply voltage detecting means 23 is less than a predetermined value TH1, for a predetermined time T1, for example, less than a predetermined cycle of the AC voltage (AC current) of the commercial AC power supply e, or this commercial AC When the voltage (current) obtained by rectifying the power source e is less than a predetermined cycle and the detected value of the DC voltage detecting means 24 is less than the predetermined value TH2, that is, when it is determined that the DC voltage conversion circuit 21 is abnormal, the DC voltage When the state where the detection value of the current detection means 36 is equal to or higher than the predetermined value TH3 continues for a predetermined time T2 or more from the timing when the detection value of the detection means 24 becomes less than the predetermined value TH2, the output current of the constant current circuit 22 is reduced. In other words, even when the control means 25 determines that the DC voltage conversion circuit 21 is abnormal, if the overcurrent flowing from the constant current circuit 22 is within the predetermined time T2, the transient of the DC voltage conversion circuit 21 is determined. It is determined that the operation is temporary (temporary) unstable, and control for reducing (stopping) the output current of the constant current circuit 22 is suspended (disabled). As a result, the transient (temporary) unstable operation of the DC voltage conversion circuit 21, such as when the power is restored or when the smoothing capacitor 34 is not warmed up to its original operation due to use at a very low temperature. Is determined based on the overcurrent flowing from the constant current circuit 22, it is possible to more reliably prevent the output of the constant current circuit 22 from being erroneously reduced (stopped).

  Further, the control means 25 determines that the state where the detection value of the power supply voltage detection means 23 is less than the predetermined value TH1, for a predetermined time T1, for example, less than a predetermined cycle of the AC voltage (AC current) of the commercial AC power supply e, or the commercial AC power supply e When the detection value of the current detection means 36 is less than the predetermined value TH3 when the detection value of the DC voltage detection means 24 is less than the predetermined value TH2 Reduce the output current of 22. In other words, the control means 25 reduces the output current of the constant current circuit 22 when, for example, the output voltage V2 from the DC voltage conversion circuit 21 decreases excessively and the constant current circuit 22 cannot output the current. (Stop. As a result, it is possible to more reliably prevent malfunctions caused by short-time fluctuations and recovery of the voltage (voltage V1) of the commercial AC power source e.

  Next, a third embodiment will be described with reference to FIG. In addition, about the structure and effect | action similar to said each embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the third embodiment, the DC power supply device 12 includes a DC voltage conversion circuit 21 that converts an AC voltage from an external power supply (commercial AC power supply e) to a DC voltage, and a load ( LED 14) detects a constant current circuit 22 that outputs a constant current, an external power source (commercial AC power source e) voltage (voltage V1), and an electrical quantity corresponding to this voltage (voltage V1). The power supply voltage detection means 23, the current detection means 36 for detecting either the load current I or the electrical quantity corresponding to the load current I, and the state where the detection value of the power supply voltage detection means 23 is less than the predetermined value TH1 is predetermined. And a control means 25 for reducing the output current of the constant current circuit 22 when the state where the detection value of the current detection means 36 continues for a predetermined time T4 or more continues for a predetermined time T4 or more. is there.

  That is, in the third embodiment, the DC power supply device 12 of the second embodiment does not include the DC voltage detecting means 24.

  The control means 25 rectifies the detection value of the power supply voltage detection means 23 and the detection value of the current detection means 36, for example, every predetermined cycle of the AC voltage (AC current) of the commercial AC power supply e or the commercial AC power supply e. The voltage (current) is sequentially acquired at a predetermined timing such as every predetermined cycle. The control means 25 controls the operation of the constant current circuit 22 based on the voltage V1 detected by the power supply voltage detection means 23 and the load current I detected by the current detection means 36.

  Specifically, the control means 25 determines that the state where the detected value of the power supply voltage detecting means 23 is less than the predetermined value TH1, for a predetermined time T3, for example, a predetermined cycle or more of the AC voltage (AC current) of the commercial AC power source e, or this commercial AC When the detected value of the power supply voltage detecting means 23 becomes less than the predetermined value TH1 when the voltage (current) obtained by rectifying the power source e continues for a predetermined cycle or more, the detected value of the current detecting means 36 exceeds the predetermined value TH4. When the state continues for a predetermined time T4, for example, longer than the predetermined time T3 for determining whether or not the detection value of the power supply voltage detection means 23 has continued, the output current of the constant current circuit 22 is reduced. That is, even when the voltage (voltage V1) of the commercial AC power source e drops for a predetermined time T3 or more, if the overcurrent flowing from the constant current circuit 22 is within the predetermined time T4, the DC voltage conversion circuit 21 is transient ( It is determined that the operation is temporarily unstable, and the output current of the constant current circuit 22 is not reduced (stopped). Therefore, for example, when the power supply is restored, or when the smoothing capacitor 34 is not warmed up to its original operation due to use at a very low temperature, etc., the DC voltage conversion circuit 21 is in a transient (temporary) unstable operation. By determining whether or not there is based on the overcurrent flowing from the constant current circuit 22, it is possible to reliably prevent the output of the constant current circuit 22 from being erroneously reduced (stopped).

  In the above control, the detection values of the power supply voltage detection means 23 and the current detection means 36 are respectively compared with each predetermined value a predetermined number of times, and the number of times determined to reduce (stop) the output of the constant current circuit 22 It may be performed when the predetermined number of times continues or when the ratio of the number of times determined to reduce (stop) the output of the constant current circuit 22 is equal to or greater than a predetermined value.

  Then, according to at least one embodiment described above, it is possible to reliably prevent malfunction caused by fluctuation and return of the voltage (voltage V1) of the commercial AC power source e.

  In each of the above embodiments, any load other than the LED 14 can be used as the load.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

11 LED lighting device as lighting device
12 DC power supply as a power supply
14 LED as a light emitting element as a load
21 DC voltage converter
22 Constant current circuit
23 Power supply voltage detection means
24 DC voltage detection means
25 Control means
36 Current detection means

Claims (5)

A DC voltage conversion circuit that converts AC voltage from an external power source into DC voltage;
A constant current circuit that is fed by the DC voltage conversion circuit and outputs a constant current to the load;
Power supply voltage detection means for detecting either the voltage of the external power supply or an electrical quantity corresponding to this voltage;
DC voltage detection means for detecting either the output voltage of the DC voltage conversion circuit or an electrical quantity corresponding to the output voltage;
Control means for reducing the output current of the constant current circuit when the detection value of the power supply voltage detection means is less than a predetermined value for less than a predetermined time and the detection value of the DC voltage detection means is less than a predetermined value;
A power supply device comprising: Comprising current detection means for detecting either a load current or an electrical quantity corresponding to the load current;
The control means is such that when the detected value of the power supply voltage detecting means is less than the predetermined value, the detected value of the DC voltage detecting means is less than the predetermined value and the detected value of the current detecting means is less than the predetermined value. The power supply apparatus according to claim 1, wherein the output current of the constant current circuit is reduced in some cases. Comprising current detection means for detecting either a load current or an electrical quantity corresponding to the load current;
The control means is configured such that the detection value of the power supply voltage detection means is less than a predetermined value for less than a predetermined time, the detection value of the DC voltage detection means is less than a predetermined value, and the detection value of the current detection means is greater than or equal to a predetermined value. 3. The power supply device according to claim 2, wherein the output current of the constant current circuit is reduced when the state continues for a predetermined time or more after the detected value of the DC voltage detecting means becomes less than the predetermined value. The control means outputs the output current of the constant current circuit when the detection value of the power supply voltage detection means is less than a predetermined value for less than a predetermined time and the detection value of the DC voltage detection means is less than a first predetermined value. And the output of the constant current circuit is stopped when the detected value of the DC voltage detecting means becomes less than a second predetermined value smaller than the first predetermined value in a state where the output current is reduced. The power supply device according to any one of claims 1 to 3. A light emitting device as a load;
The power supply device according to any one of claims 1 to 4, which is connected to an external power supply and outputs a constant current to the light emitting element;
An illumination device comprising:

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