JP5645303B2 - Remote control one converter power supply circuit - Google Patents

Description

  The present invention relates to a remote control one-converter power supply circuit.

  As a conventional technique, an AC-DC converter that realizes a power factor improving function and a function of obtaining a stable direct current by turning on and off one switching element using a control IC (Integrated Circuit) is known. (For example, refer to Patent Document 1). A load driven by a direct current is connected to the AC-DC converter. However, the conventional AC-DC converter cannot finely control the driving of the load.

JP 2006-136076 A

  An object of the present invention is to provide a remote control one-converter power supply circuit capable of continuously controlling driving of a connected DC load while realizing power factor improvement and generation of a DC current with a single converter. There is.

[1] In order to achieve the above object, the present invention provides a one-converter circuit that performs power factor improvement and generation of a direct current based on a reference voltage by a single converter and supplies the direct current to a direct current load. receives an operation to instruct the driving state of the DC load, an operating unit for generating a control signal corresponding to the operation amount of the operation to generate a pre-Symbol reference voltage based on the control signal which the operating portion is generated The converter circuit that outputs the generated reference voltage to the one converter circuit, and the DC current that the one converter circuit supplies to the DC load so that the reference voltage and the voltage fed back from the DC load are equal. And a remote control one-converter power supply circuit including a control circuit for controlling the power supply.
[2] In order to achieve the above object, the present invention further includes a feedback amplifier circuit that amplifies the signal output from the conversion circuit, and a filter circuit that averages the signal output from the feedback amplifier circuit. A remote control one-converter power supply circuit according to [1] above is provided.
[3] The control circuit includes: a switch circuit that is turned on and off based on first and second switch signals; a power supply circuit that supplies a direct current to the DC load by turning on and off the switch circuit; The first and second switch signals based on a reference voltage are output to the switch circuit, and the power supply circuit stores electrical energy based on a direct current from a rectifier circuit when the switch circuit is on, A storage circuit that outputs a direct current based on the stored electrical energy, a first capacitor connected in series with the direct current load and charged by the direct current from the storage circuit, and in parallel with the direct current load And a second capacitor that is charged by the DC current from the storage circuit, and the DC load has the switch circuit turned on. When driven by a direct current from the storage circuit and the first capacitor, and driven by a direct current from the second capacitor when the switch circuit is off, [1] or [2] Remote control one converter power supply circuit.

  The present invention can continuously control the driving of the connected DC load while realizing the power factor improvement and the generation of the DC current with a single converter.

FIG. 1 is a circuit diagram of a remote control one-converter power supply circuit according to an embodiment of the present invention. FIG. 2A is a graph of the PWM signal input to the PWM level conversion circuit according to the embodiment of the present invention, and FIG. 2B is a graph of the reference voltage VRef input to the one converter circuit.

[Embodiment]
(Configuration of power supply circuit)
FIG. 1 is a circuit diagram of a remote control one-converter power supply circuit according to an embodiment of the present invention. The remote control one-converter power supply circuit 10 mainly includes a one-converter circuit 30 that performs power factor improvement and generation of a direct current based on the reference voltage VRef with a single converter and supplies the direct-current to a direct-current load. A PWM level conversion circuit 50 that generates a reference voltage VRef from a PWM (Pulse Width Modulation) signal as a control signal for controlling the driving state of the DC load, and outputs the generated reference voltage VRef to the one converter circuit 30. It is roughly structured.

  Further, as shown in FIG. 1, the remote control one-converter power supply circuit 10 includes a rectifier circuit 20 and a buffer amplifier 60 as a feedback amplifier circuit that amplifies the PWM signal that has been level-converted and output from the PWM level conversion circuit 50. And a filter 70 that averages the PWM signal amplified and output from the buffer amplifier 60 so as to have a voltage of 2.5 to 2.7 V in accordance with the duty ratio. .

  The direct current load (constant current load) connected to the output terminal of the one converter circuit 30 is not particularly limited, but is an illumination device such as an organic EL (Organic Electro-Luminescence) or LED (Light Emitting Diode). For example, an LED series circuit 40 in which a plurality of light emitting diodes (LEDs) 41,.

  In the remote control one-converter power supply circuit 10, a controller 80 is connected to the connector 51 of the PWM level conversion circuit. For example, the controller 80 is configured to output a PWM (Pulse Width Modulation) signal corresponding to the operation amount by operating the volume 81. For example, the remote control one-converter power supply circuit 10 performs dimming of a lighting device connected in accordance with the PWM signal. For example, the controller 80 can select any manufacturer or type as long as it outputs a PWM signal corresponding to the operation amount of the volume 81.

(Configuration of rectifier circuit)
As shown in FIG. 1, the rectifier circuit 20 includes a diode bridge 21 formed of, for example, four diodes. The rectifier circuit 20 performs full-wave rectification on the AC voltage input from the commercial AC power supply 11 through the input terminal and converts the AC voltage into a DC voltage. This DC voltage is supplied to the one converter circuit 30 through the output terminal of the rectifier circuit 20.

(One converter circuit configuration)
As shown in FIG. 1, the one converter circuit 30 is a circuit that generates a constant DC current by stepping up or down an input voltage to a desired voltage, and includes a ripple current removing capacitor 22, a transformer Tr, and a rectifier diode D1. , A switching element (MOSFET) Q, a primary capacitor C1, a backflow prevention diode D2, a secondary capacitor C2, and a control IC 31.

  In the illustrated example, a power supply circuit is configured by the ripple current removing capacitor 22, the transformer Tr, the rectifier diode D1, the primary capacitor C1, the backflow prevention diode D2, and the secondary capacitor C2. The transformer Tr, the primary capacitor C1, and the secondary capacitor C2 constitute an accumulation circuit. The direct current whose power factor has been improved by the one converter circuit 30 is output to the LED series circuit 40 through the output terminal.

  As shown in FIG. 1, the control IC 31 is composed of an integrated circuit that improves the power factor by aligning the input voltage from the rectifier circuit 20 and the waveform of the input current flowing through the switching element Q. This type of control IC 31 is not particularly limited. For example, a circuit that is integrated into an IC for harmonic current suppression or power factor improvement, such as FA5500 and FA5501 manufactured by Fuji Electric Co., Ltd., is used. Can do.

  According to the illustrated example, the control IC 31 is provided with a power supply voltage input VCC terminal, a ground connection GND terminal, a feedback signal input FB terminal, and first and second switch signals for switching drive. An OUT terminal for switching, an IS terminal for detecting switching current, a ZCD terminal for detecting zero current, and a MUL terminal for voltage input proportional to the full-wave rectified voltage are shown. The control IC 31 generates a control pulse based on input signals to the VCC terminal, FB terminal, MUL terminal, IS terminal, and ZCD terminal. The power factor is improved by changing the magnitude of the output current in accordance with the time during which the switching element Q that is on / off controlled by the control pulse is turned on.

  A capacitor C3 is connected between the VCC terminal and the GND terminal of the control IC 31 as shown in FIG. One end of the capacitor C3 is connected to the auxiliary power supply voltage VCC, and the other end of the capacitor C3 is connected to the ground. A positive terminal (+) of the rectifier circuit 20 is connected between one end of the capacitor C3 and the auxiliary power supply voltage VCC via a resistor R1. A connection point between the resistor R1 and the capacitor C3 is connected to the second winding Tr2 of the transformer Tr via a backflow preventing diode D4.

  Between the positive terminal of the rectifier circuit 20 and the GND terminal of the control IC 31, as shown in FIG. 1, it is connected to a voltage dividing resistor composed of resistors R2 and R3. The output of the voltage dividing resistor is connected to the MUL terminal of the control IC 31. A sine wave full-wave rectified voltage (voltage waveform proportional to the absolute value voltage of the commercial AC power supply 11) obtained by dividing the full-wave rectified voltage of the rectifier circuit 20 by the resistors R2 and R3 is input to the MUL terminal. This prevents the generation of lowering and harmonic current.

  As shown in FIG. 1, the remote control one-converter power supply circuit 10 has a single transformer Tr. The transformer Tr is composed of a first winding Tr1 and a second winding Tr2. One end of the first winding Tr1 is connected to the positive terminal of the rectifier circuit 20. The other end of the first winding Tr1 is connected to one end (negative terminal) of the LED series circuit 40 through a series circuit including a rectifier diode D1, a primary capacitor C1, and a backflow prevention diode D2. A charging diode D3 is connected to one end of the first winding Tr1 and a connection point between the primary capacitor C1 and the cathode of the backflow prevention diode D2. When the switching element Q is in the OFF state, the primary capacitor C1 is charged by circulating current through the closed circuit of the rectifier diode D1, the primary capacitor C1, the charging diode D3, and the primary winding Tr1 of the transformer Tr.

  As shown in FIG. 1, the backflow prevention diode D2 prevents the charging current to the primary capacitor C1 from backflowing. A secondary capacitor C2 is connected in parallel with the LED series circuit 40 between the anode of the backflow prevention diode D2 and the negative terminal of the rectifier circuit 20. The drain of the switching element Q is connected to the connection point of the rectifier diode D1 and the primary capacitor C1. The source of the switching element Q is connected to the ground via a current detection resistor R4. The connection point of the source of the switching element Q and the resistor R4 is connected to the IS terminal of the control IC 31 via the resistor R5, and detects the switching current of the switching element Q. The gate of the switching element Q is connected to the OUT terminal of the control IC 31 via the resistor R6.

  As shown in FIG. 1, the second winding Tr2 of the transformer Tr is in a state of being electrically insulated from the first winding Tr1 that is the primary winding. One end of the second winding Tr2 is connected to the ground. The other end of the second winding Tr2 is connected to the ZCD terminal of the control IC 31 via a resistor R7, and the value of the current flowing through the transformer Tr is detected. When the switching element Q changes from the on state to the off state, the second winding as the secondary winding is generated by a voltage proportional to the induced voltage of the first winding Tr1 induced in the second winding Tr2 as the secondary winding. It is configured such that a current flows through Tr2. When it is detected that the current of the transformer Tr has returned to zero based on the voltage from the second winding Tr2, the switching element Q is turned on.

  As shown in FIG. 1, a series circuit composed of resistors R8, R9, and R10 is connected to one end (positive terminal) of the secondary capacitor C2. A non-inverting input terminal of the inverting amplifier 32 is connected to a connection point between the resistor R9 and the resistor R10. The resistors R9 and R10 constitute a current detection circuit that detects a current flowing through the LED series circuit 40.

  The inverting input terminal of the inverting amplifier 32 is connected to a resistor R11 as an input resistor for determining an amplification factor and a resistor R12 as a feedback resistor, and the resistor R11 is connected to the filter 70. The one converter circuit 30 converts the voltage level of the current flowing through the LED series circuit 40 detected by the resistor R8 by using the resistors R9 and R10 and inputs the voltage level to the non-inverting input terminal of the inverting amplifier 32, and inputs it to the non-inverting input terminal. The feedback control is performed so that the obtained voltage becomes equal to the reference voltage VRef input to the inverting input terminal of the inverting amplifier 32. The remote control one-converter power supply circuit 10 can dimm the light emitting diode 41 of the LED series circuit 40 by this feedback control. A capacitor C4 for filtering the full-wave rectified ripple waveform included in the direct current is connected in parallel to the resistor R12. Next, generation of the reference voltage VRef will be described.

(Regarding the generation of the reference voltage VRef)
FIG. 2A is a graph of the PWM signal input to the PWM level conversion circuit according to the embodiment of the present invention, and FIG. 2B is a graph of the reference voltage VRef input to the one converter circuit. 2A and 2B, the horizontal axis indicates time t, and the vertical axis indicates voltage V. The frequency of the PWM signal output from the controller 80 is, for example, 1 KHz.

  For example, the PWM signal shown in FIG. 2A has a voltage V of 10 V at times t1 to t2 and times t3 to t4, and a voltage V of 0 V at times t2 to t3. FIG. 2A shows a case where the times t1 to t2, the times t2 to t3, and the times t3 to t4 are equal to each other with a duty ratio of 50%.

  For example, the light emitting diode 41 of the LED series circuit 40 is turned off (light control depth 0%) when the reference voltage VRef is 2.7V, and is turned on (light control depth 100%) when the reference voltage VRef is 2.5V. As described above, the remote control one-converter power supply circuit 10 is configured. Further, for example, the light control depth of 50% is realized when the duty ratio of the PWM signal input from the controller 80 is 50% as shown in FIG. 2A, and the reference voltage VRef at this time is shown in FIG. As shown in 2 (b), the voltage is 2.6V. The control IC 31 performs feedback control so that the voltage value input to the inverting input terminal of the inverting amplifier 32 is equal to the voltage value input to the non-inverting input terminal. Therefore, the control IC 31 outputs the LED from the one converter circuit 30 based on the reference voltage VRef. The direct current supplied to the series circuit 40 changes, and the light-emitting diode 41 can be dimmed.

  For example, the PWM level conversion circuit 50 includes a connector 51, a photocoupler 52, resistors R13 to R16, diodes D5 and D6, and a Zener diode D7.

  The PWM level conversion circuit 50 is, for example, a circuit that converts the level of a 0-10V or 12V PWM signal output from the controller 80 into a 2.5-2.7V PWM signal.

  The photocoupler 52 is schematically configured to include, for example, diodes D5 and D6 and a light receiving element 53. In this photocoupler 52, the diode D5 or D6 is turned on according to the PWM signal adjusted by the resistor R13 connected between the diode D5 and the connector 51, and the light received by the light receiving element 53 is received by the light receiving element 53. A signal corresponding to light is output.

  One end of the output terminal of the photocoupler 52 is connected to the resistor R14, and the other end is connected to the resistor R16. The connection point between the resistors R14 and R15 is connected to the auxiliary power supply voltage VCC. The other end of the resistor R15, which is different from one end connected to the auxiliary power supply voltage VCC and the resistor R14, is connected to the other end of the resistor R16, which is different from the one end connected to the light receiving element 53, and the connection point further includes a Zener diode D7. Is grounded. The Zener diode D7 is arranged for the purpose of stably generating a voltage of 2.5 V with the cathode grounded.

  A connection point of the resistor R16 connected to the light receiving element 53 is connected to the buffer amplifier 60. When the photocoupler 52 is off, the voltage 2.5 V generated by the Zener diode D7 is output to the buffer amplifier 60. When the photocoupler 52 is on, the divided value (0.2V) divided by the resistors R14 and R16 is added to the voltage 2.5V generated by the Zener diode D7, and the voltage 2.7V is buffer amplifier. 60. That is, a voltage of 2.5 to 2.7 V is output to the inverting input terminal of the buffer amplifier 60. Since the PWM level conversion circuit 50 can generate a voltage of 2.5 to 2.7 V according to the PWM signal, the remote control one converter power supply circuit 10 outputs the output of the PWM level conversion circuit 50 to the one converter circuit. 30 may be output.

  The buffer amplifier 60 is, for example, a 1 × amplification amplifier that performs negative feedback amplification, and its output is output to the filter 70.

  The filter 70 forms an integrating circuit by the resistor R17 and the capacitor C5 in order to average the PWM signal. The cut-off frequency of the filter 70 is set to about 50 Hz with 5% as a guide because the frequency of the PWM signal is 1 KHz.

(Operation of one converter power supply circuit)
First, the power factor improvement and the operation of supplying a constant direct current to the LED series circuit 40 will be described with reference to the drawings.

  When the commercial AC power supply 11 is applied to the remote control one converter power supply circuit 10, the power supply voltage from the commercial AC power supply 11 is supplied to the rectifier circuit 20. The power supply voltage is full-wave rectified by the rectifier circuit 20, and then the full-wave rectified DC current is supplied to the one converter circuit 30. A direct current is supplied to the control IC 31 to start the operation, and a gate voltage is applied to the switching element Q.

  In FIG. 1, when the switching element Q is in the ON state, a switching current flows to the ground through the switching element Q. The current energy at that time is accumulated in the first winding Tr1 of the transformer Tr. Thereafter, when the switching element Q is turned off, the inflow of current to the first winding Tr1 is stopped, and the current energy accumulated in the first winding Tr1 is released through the rectifier diode D1, and is supplied to the primary capacitor C1. Accumulated. The primary capacitor C1 functions as a first output power supply when the switching element Q is in an on state. The current energy stored in the primary capacitor C1 is released, and a current flows in the closed circuit of the switching element Q, the secondary capacitor C2, and the primary capacitor C1 to supply a charging current to the secondary capacitor C2, and the switching element Q, LED A current flows in the closed circuit of the series circuit 40, the backflow prevention diode D2, and the primary capacitor C1.

  On the other hand, the output of the voltage dividing resistor composed of the resistors R9 and R10 which are current detection circuits of the LED series circuit 40 is input to the non-inverting input terminal of the inverting amplifier 32 as shown in FIG. The control IC 31 performs feedback control so that the output of the voltage dividing resistor input to the non-inverting input terminal becomes equal to the reference voltage VRef input to the inverting input terminal of the inverting amplifier 32.

  Further, the control IC 31 generates a switching signal for driving the switching element Q based on the voltage input to the FB terminal and controls the switching element Q, so that the control IC 31 flows to the first winding Tr1 that is the primary winding of the transformer Tr. The average value of the current is equal to the voltage waveform of the commercial AC power supply 11, and it is possible to improve the power factor and suppress the harmonic current. Further, the remote control one-converter power supply circuit 10 can supply a constant direct current to the LED series circuit 40.

  Next, the dimming operation of the light emitting diode 41 of the LED series circuit 40 by the remote control one converter power supply circuit 10 will be described.

  The user operates the volume 81 of the controller 80 to dimm the light emitting diode 41.

  The controller 80 outputs a PWM signal based on the operation amount of the volume 81. This PWM signal has a duty ratio based on the operation amount.

  The PWM signal is input to the PWM level conversion circuit 50 via the connector 51. The PWM level conversion circuit 50 converts the level of the input PWM signal and outputs it to the buffer amplifier 60. Specifically, when the photocoupler 52 is off, the PWM level conversion circuit 50 outputs the PWM signal level-converted to a voltage of 2.5 V generated by the Zener diode D7 to the buffer amplifier 60, and the photocoupler 52 is turned on. At this time, the PWM signal level-converted to a voltage 2.7 V obtained by adding the divided voltage value (0.2 V) divided by the resistors R 14 and R 16 to 2.5 V is output to the buffer amplifier 60.

  The level-converted PWM signal input to the buffer amplifier 60 is negative feedback amplified and output to the filter 70. The filter 70 averages the amplified PWM signal so as to have a voltage of 2.5 to 2.7 V according to the duty ratio, and outputs the averaged voltage to the one converter circuit 30 as a reference voltage VRef.

  As described above, the control IC 31 of the one converter circuit 30 converts the voltage level of the current flowing through the LED series circuit 40 detected by the resistor R8 using the resistors R9 and R10, and the non-inverting input terminal of the inverting amplifier 32. The feedback control is performed so that the voltage input to the non-inverting input terminal becomes equal to the reference voltage VRef input to the inverting input terminal of the inverting amplifier 32. By this feedback control, the light emitting diode 41 emits light at a light control depth corresponding to the operation amount of the volume 81 of the controller 80 because the direct current supplied from the one converter circuit 30 changes.

  Depending on the controller 80, even if the volume 81 is completely reduced, the dimming depth does not become 0%. Therefore, a variable resistor is added between the resistor R14 of the PWM level conversion circuit 50 and the auxiliary power supply voltage VCC. Thus, the voltage value output to the buffer amplifier 60 may be controlled.

(effect)
The remote control one-converter power supply circuit 10 described above is a one-converter type that performs power factor improvement and DC current generation with a single converter, but can dimm the light-emitting diode 41 connected to this circuit. .

  Further, the remote control one-converter power supply circuit 10 is connected by adding simple circuits such as a PWM level conversion circuit 50, a buffer amplifier 60, and a filter 70 as compared with the case where the dimming function is incorporated in the control IC 31. Since the light emitting diode 41 can be dimmed, the cost is reduced.

  Furthermore, since the remote control one-converter power supply circuit 10 performs dimming based on the PWM signal output from the controller 80, various commercially available controllers can be used, and the versatility is high.

  Furthermore, the remote control one-converter power supply circuit 10 can generate a constant direct current by stepping up or down the input voltage to a desired voltage according to the connected direct current load.

  In the above embodiment, the power supply circuit of the lighting device has been illustrated, but the present invention is not limited to this. In the case of a constant current load, the present invention can be effectively used as a power circuit for driving a DC motor such as an air conditioner, a refrigerator, a ventilation fan or a pump, for example. In the case of a constant voltage load, For example, it can be used as a general-purpose DC voltage power source. Therefore, the present invention is not limited to the above embodiments, and various design changes are possible.

DESCRIPTION OF SYMBOLS 10 ... Remote control one converter power supply circuit, 11 ... Commercial alternating current power supply, 20 ... Rectifier circuit, 21 ... Diode bridge, 22 ... Capacitor, 30 ... One converter circuit, 32 ... Inverting amplifier, 33 ... Error amplifier, 34 ... Multiplier, 35 ... Comparator, 36 ... Flip-flop, 37 ... Driver, 38 ... Zero current detector, 40 ... LED series circuit, 41 ... Light emitting diode, 50 ... PWM level conversion circuit, 51 ... Connector, 52 ... Photo coupler, 53 ... Light receiving element, 60 ... Buffer amplifier, 70 ... Filter, 80 ... Controller, 81 ... Volume, C1 ... Primary capacitor, C2 ... Secondary capacitor, C3-C5 ... Capacitor, D1-D6 ... Diode, D7 ... Zener diode, 31 ... Control IC, Q ... switching element, R ... reset terminal, R1-R17 ... resistor , Tr ... transformer, Tr1 ... first winding, Tr2 ... second winding, VCC ... auxiliary power voltage, VRef ... reference voltage

Claims (3)

One converter circuit that performs power factor improvement and generation of a direct current based on a reference voltage in one converter and supplies the direct current to a direct current load;
An operation unit that receives an operation instructing a driving state of the DC load and generates a control signal according to an operation amount of the operation;
A conversion circuit for the operation unit to generate a pre-Symbol reference voltage based on the control signal generated, and outputs the generated the reference voltage to the one converter circuit,
A control circuit for controlling the DC current supplied to the DC load by the one converter circuit so that the reference voltage and the voltage fed back from the DC load are equal;
Remote control one converter power supply circuit equipped with.   The remote control one-converter power supply circuit according to claim 1, further comprising: a feedback amplifier circuit that amplifies the signal output from the conversion circuit; and a filter circuit that averages the signal output from the feedback amplifier circuit. . The control circuit includes a switch circuit that is turned on and off based on first and second switch signals, a power supply circuit that supplies a direct current to the DC load by turning on and off the switch circuit, and the reference voltage. Outputting the first and second switch signals based on the switch circuit ,
The power supply circuit includes:
When the switch circuit is on, the storage circuit stores electrical energy based on the direct current from the rectifier circuit, and outputs the direct current based on the stored electrical energy;
A first capacitor connected in series with the DC load and charged by the DC current from the storage circuit;
A second capacitor disposed in parallel with the DC load and charged by the DC current from the storage circuit;
The DC load is driven by a direct current from the storage circuit and the first capacitor when the switch circuit is on, and is driven by a direct current from the second capacitor when the switch circuit is off. The remote control one-converter power supply circuit according to claim 1 or 2.

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