JP6033092B2 - Power supply device, LED lighting device, and battery charging device - Google Patents

Description

  The present invention relates to a power supply device that raises and lowers a power supply voltage, and an LED lighting device and a battery charging device using the power supply device.

  In the current trend of reducing carbon dioxide emissions that contribute to global warming, it is an alternative to conventional tungsten filament bulbs as light sources for in-vehicle tail lamps, position lamps, and indoor lighting. Power LEDs (light emitting diodes, semiconductor light sources) have become widespread. Since this LED has a long life and can emit light with stable brightness by simple control that supplies a constant current, it is suitable not only for general lighting but also as a light source for in-vehicle lamps. It is.

  On the other hand, the demand for electric vehicles with low carbon dioxide emissions is increasing, and the spread is accelerating. The electric vehicle is equipped with a charging device for charging a power battery.

As the lighting device for lighting the LED and the charging device for charging the battery as described above, a power supply device that arbitrarily operates the output power is used although the power capacity is different.
A general power supply device uses a switching power supply that uses a coil or a capacitor and a switching element. Typical methods for switching power supplies that use coils and switching elements include step-up power supplies (boost converters and boost converters) in which the output voltage is higher than the power supply voltage, and step-down power supplies (buck) in which the output voltage is lower than the power supply voltage. Converter, step-down converter). Similarly, as a typical method of a switching power supply using a capacitor and a switching element, there are a charge pump type step-up power supply in which the output voltage is equal to or higher than the power supply voltage, and a step-down power supply in which the output voltage is equal to or lower than the power supply voltage.

Below, the patent documents 1-3 which described the structure of the power supply device are shown.
The series-parallel connection switching type capacitor power storage device according to Patent Document 1 is a configuration example in which a step-up power source and a step-down power source are combined. The original object of the invention according to Patent Document 1 is to switch capacitors connected in parallel in series in order to efficiently discharge the power stored in the capacitors, when the voltage drops due to power discharge, and to switch the output voltage. Is ensured, and electric power is efficiently discharged.

  Further, the charge pump circuit according to Patent Document 2 is a configuration example of a charge pump type step-up power supply using a capacitor.

  Further, the power supply device according to Patent Document 3 uses two capacitors, and connects both capacitors in series for charging, and outputs a voltage that is ½ of the power supply voltage by discharging in parallel. It is a structural example of a power supply device.

Japanese Patent Laid-Open No. 10-174284 JP 2004-248453 A JP 2002-325431 A

  Any switching power supply using a coil or capacitor and a switching element as described above has a completely different circuit configuration depending on whether the output voltage is higher or lower than the power supply voltage. Therefore, for example, in an LED lighting device that outputs a 12V LED lighting voltage using a vehicle-mounted battery that varies from 8V to 16V as a power source, it is necessary to use a step-up / down converter that combines different circuit configurations. For example, in the power supply device of Patent Document 1 using a coil and a switching element, in order to output a voltage lower than the power supply voltage and a voltage higher than the power supply voltage, the coil is shared by the step-down chopper circuit and the step-up chopper circuit, The switching element for the step-down chopper circuit and its control circuit, and the switching element for the step-up chopper circuit and its control circuit are provided.

  Further, for example, in a battery charger for charging a power battery of an electric vehicle that is about 400 V when charging is completed and is reduced to about 200 V after discharging, using an AC power source of 100 Vrms or 200 Vrms as a power source, similarly to the above, A circuit configuration that outputs a voltage higher than the power supply voltage (output 400 V when the power supply is 100 Vrms) from a low voltage (output 200 V when the power supply is 200 Vrms) is required.

  Combining the boosting and bucking configurations in this way is to simultaneously mount components corresponding to each of them, and there is a problem that the power supply device naturally becomes large and costs increase.

  The present invention has been made to solve the above-described problems, and has a simple configuration that can output a wide range of voltages from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage, and the power supply apparatus. An object of the present invention is to provide an LED lighting device and a battery charging device using the battery.

A power supply device according to the present invention includes a switching element, a coil having one terminal connected to the power supply side, and the other terminal connected to the switching element, a plurality of rectifier diodes that generate an output current, a coil and the switching element It has a capacitor that connects one terminal to the connection point and connects the other terminal to the rectifier diode side, and a control unit that operates the switching element. The rectifier diode is both when the switching element is turned on and when it is turned off. in, it is one that an output current from the capacitor, a voltage higher than the power supply voltage generated at the terminals of the coil divided by a capacitor, and outputs rectifies that current to flow to the capacitor by the rectifier diode.

  The LED lighting device according to the present invention lights an LED using the power supply device described above.

  The battery charging device according to the present invention charges a battery using the above-described power supply device.

  According to the present invention, the power supply voltage is boosted by the step-up power supply composed of the coil and the switching element, and the boosted voltage is divided into two by the capacitor and the load, so that the output voltage applied to the load is boosted. Therefore, it is possible to output a wide range of voltages from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage without adding a step-down switching element and its control circuit. A power supply device can be provided.

  According to the present invention, since the power supply device capable of outputting a wide range of voltages from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage is used, the forward voltage of the LED is a voltage lower than the power supply voltage. Thus, an LED lighting device that can be lit even in a wide range of voltages from a power supply voltage to a voltage higher than the power supply voltage can be realized with a simple configuration.

  According to the present invention, since the power supply device capable of outputting a wide range of voltages from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage is used, the battery voltage is changed from the voltage lower than the power supply voltage to the power supply voltage. A battery charger capable of charging even a wide range of voltages up to a higher voltage can be realized with a simple configuration.

It is a circuit diagram which shows the structure of the power supply device which concerns on Embodiment 1 of this invention. 3 is a graph showing operation waveforms of the power supply device according to the first embodiment. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 1 to the LED lighting device, and shows the case where the output side rectifier diode is provided. It is a graph which shows the waveform of the LED terminal voltage and distribution | circulation current of the power supply device shown in FIG. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 1 to the LED lighting device, and shows the case where LED serves as a rectification | straightening effect | action. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 1 to the LED lighting device, and shows the case where the coil for current limiting is provided. It is a graph which shows the waveform of the voltage between capacitor | condenser terminals of the power supply device shown in FIG. 6, and a flowing current. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 2 of this invention to the LED lighting device, and shows the case where an insulation type transformer is provided. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 2 to the battery charging device, and shows the case where a single volume transformer is provided. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 2 to the battery charging device, and shows the case where the coil for current limiting is provided. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 3 of this invention to the LED lighting device, and shows the case where it connects to AC power supply. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 3 to an LED lighting device, and shows the case where it connects to AC power supply. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 3 to a battery charging device, and shows the case where it connects to AC power supply. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 4 of this invention to LED lighting device, and shows the case where a bidirectional | two-way switching element is used. It is a circuit diagram which shows the structural example which applied the power supply device which concerns on Embodiment 4 to the LED lighting device, and shows the case where a bidirectional | two-way switching element is used. FIG. 10 is a circuit diagram illustrating an example of a signal transmission circuit of a power supply device according to a fourth embodiment. FIG. 10 is a circuit diagram showing another example of a signal transmission circuit of a power supply device according to Embodiment 4. FIG. 10 is a circuit diagram showing another example of a signal transmission circuit of a power supply device according to Embodiment 4. FIG. 10 is a circuit diagram showing another example of a signal transmission circuit of a power supply device according to Embodiment 4. FIG. 10 is a circuit diagram illustrating a configuration example in which a power supply device according to a fifth embodiment is applied to a battery charging device, and illustrates a case where a winding ratio of a primary winding of a transformer is switched.

Embodiment 1 FIG.
The power supply device 10 shown in FIG. 1 includes a switching type step-up power supply (boost converter, boost converter) that uses a coil L1 and a switching element SW1, and steps down the voltage by stepping up the step-up voltage boosted by the coil L1 by the capacitor C1. By doing so, the power supply voltage of the DC power supply 1 is converted into a predetermined voltage.

  One terminal of the coil L1 is connected to the DC power source 1, and the other terminal is connected to the switching element SW1. One terminal of the capacitor C1 is connected to the connection point between the coil L1 and the switching element SW1, and the other terminal of the capacitor C1 is connected to the load 2. The control unit 11 outputs a drive signal for controlling the on / off operation of the switching element SW1 based on the power supply voltage and the power supply current measured by the shunt resistor R1.

  This power supply device 10 includes a capacitor C1 connected in series with an output terminal of a coil L1 that raises the power supply voltage of the DC power supply 1, and a step-up voltage that is higher than the power supply voltage by a load 2 connected to the capacitor C1. By dividing into two, the voltage applied to the load 2, that is, the output voltage is lowered to ½ or less of the step-up voltage.

  FIG. 2 shows operation waveforms of the power supply device 10 according to the first embodiment. 2A shows the on / off operation of the switching element SW1, FIG. 2B shows the current flowing through the coil L1, FIG. 2C shows the drain current and drain terminal voltage of the switching element SW1, and FIG. 2D shows the capacitor C1. 2 (e) shows the current and terminal voltage flowing through the load 2, and FIG. 2 (f) shows the waveform of the current (power supply current) flowing through the shunt resistor R1. Show time.

  In accordance with the drive signal output from the control unit 11, the switching element SW1 is turned on to energize the coil L1 (broken arrow in FIG. 1), the magnetic energy is stored, the switching element SW1 is turned off, and the stored magnetic energy is stored. discharge. When the switching element SW1 is turned off, a boosted voltage is generated in the coil L1, and a positive current is passed through the load 2 while storing a charge in the capacitor C1 connected in series with the coil L1 (FIG. 1 dash-dot arrow). When the switching element SW1 is turned on again, a current is supplied to the coil L1, and while storing magnetic energy, the charge stored in the capacitor C1 is simultaneously discharged, and a negative current is supplied to the load 2 (see FIG. 1). Dotted line arrow). Therefore, although the current output to the load 2 has a different polarity, power can be output to the load 2 both when the switching element SW1 is turned on and when it is turned off.

Note that the voltage (polarity is positive) applied to the load 2 when the switching element SW1 is turned off is a voltage obtained by subtracting the inter-terminal voltage of the capacitor C1 from the voltage generated at the drain terminal of the switching element SW1. A voltage (polarity is negative) applied to the load 2 when the switching element SW1 is turned on is a voltage between terminals of the capacitor C1.
At this time, the absolute value of the terminal voltage of the load 2 in FIG. 2E is about ½ of the drain terminal voltage of the switching element SW1 in FIG. That is, the step-up voltage output from the step-up power source composed of the coil L1 and the switching element SW1 is essentially equal to or higher than the power source voltage of the DC power source 1, but the step-up voltage is divided into two by the capacitor C1 and the load 2. As a result, the output voltage applied to the load 2 is reduced to ½ of the step-up voltage. Therefore, not only when the DC power supply 1 becomes lower than the output voltage but also when the DC power supply 1 becomes higher than the output voltage. Any voltage value can be easily output. Thus, by using a configuration in which the voltage boosted by the step-up power supply is halved, for example, when an in-vehicle battery that varies from 8V to 16V is used as the DC power supply 1, 12V is output at any power supply voltage. be able to.

FIG. 3 is a circuit diagram illustrating a configuration example of the power supply device 10 when the LED 2 a is used as the load 2. In the configuration example of FIG. 3, four rectifier diodes D1 to D4 are connected between the capacitor C1 and the LED 2a, and the positive and negative currents flowing from the capacitor C1 to the LED 2a are full-wave rectified (or both waves). Rectified) to direct current.
At this time, as shown in FIG. 4, the terminal voltage of the LED 2a is about ½ of the drain terminal voltage of the switching element SW1 shown in FIG. That is, a step-up power supply that can output only a voltage higher than the power supply voltage can be a power supply that can output a voltage lower than the power supply voltage or a voltage at the same level as the power supply voltage.

  Further, the control unit 11 turns on and off the switching element SW1 so that the current flowing through the coil L1 is in a critical mode or a continuous mode (FIG. 2B), and the switching element is used by using a plurality of rectifier diodes D1 to D4. Since the output current flows from the capacitor C1 both when the SW1 is turned on and when the SW1 is turned off, the input current and the output current flow almost continuously. Therefore, an output voltage or output current with less ripple as shown in FIG. 4 can be obtained. Furthermore, since ripples are reduced, the capacity of a capacitor (not shown) that filters the power supply and the output can be reduced, and the power supply device 10 can be reduced in size and cost.

  FIG. 5 is a circuit diagram illustrating a configuration example of the power supply device 10 when the LEDs 2 a and 2 b are used as the load 2. Since the LED has diode characteristics, a configuration in which the rectifier diodes D1 to D4 shown in FIG. 4 are not used is also possible. Therefore, in the configuration example of FIG. 5, the anode terminal of the LED 2a is connected to the output terminal of the capacitor C1, and a positive current is applied. On the contrary, the cathode terminal of the LED 2b is connected to the output terminal of the capacitor C1 and has a negative polarity. Energize the current. Thereby, the rectifier diodes D1 to D4 that rectify the output current can be omitted, and the power supply device 10 can be configured simply.

  Note that when a current is applied to one of the LEDs 2a and 2b, for example, the LED 2a, the voltage between the terminals of the LED 2a is a forward voltage, and the forward voltage is less than or equal to the reverse withstand voltage of the other LED 2b. If there is, there is no problem. Generally, the reverse withstand voltage (for example, 5 to 6 V) is higher than the forward voltage (for example, 2 to 3 V).

  Incidentally, each of the LED 2a and the LED 2b is energized with a current of either positive or negative polarity flowing through the capacitor C1, so that the LED 2a and the LED 2b are alternately lit. That is, the LEDs 2a and 2b blink. However, in general, if the blinking frequency is 200 Hz or more, it is not visually recognized as flickering, so blinking lighting has no practical problem. In addition, since the time during which each of the LEDs 2a and 2b is energized is approximately halved, the loss (heat generation amount) is the same even if the energization current is doubled. Therefore, a decrease in the amount of light emission due to the blinking lighting can be avoided by increasing the energization current.

FIG. 6 is a circuit diagram illustrating a configuration example of the power supply device 10 when the current limiting coil L2 is inserted into a discharge path (indicated by a two-dot chain line) for discharging the charge of the capacitor C1. FIG. 7 shows a current (solid line) and a terminal voltage (broken line) that flow in the capacitor C1 when the current limiting coil L2 is not used, and a current that flows through the capacitor C1 when the current limiting coil L2 is used (dashed line). ) And the voltage between terminals (two-dot chain line). As shown in FIG. 7, since the rush current (surge) can be reduced by inserting the current limiting coil L2, an excessive load is not applied to the switching element SW1, and the generation of noise is also suppressed.
Incidentally, since the step-up coil L1 is inserted in the charging path (indicated by the alternate long and short dash line) for storing charges in the capacitor C1, no inrush current flows.

As described above, the power supply device 10 divides the voltage stepped up by the coil L1 and the switching element SW1 into two by the capacitor C1 and the LED 2a (or LEDs 2a and 2b), and outputs from the output terminal of the capacitor C1. A substantially rectangular wave-shaped AC waveform that changes to both positive and negative polarities is aligned in one direction in both positive and negative directions by a plurality of rectifier diodes D1 to D4 (or LEDs 2a and 2b) and output as a direct current. That is, the voltage boosted by the coil L1 and the switching element SW1 is halved, and the current divided by the switching element SW1 is interpolated to output a continuous current.
The configuration in which the capacitor C1 and the plurality of rectifier diodes D1 to D4 are added to the step-up power supply is not described in any of Patent Documents 1 to 3 described above.

Next, the control unit 11 will be described.
The control unit 11 performs PWM (Pulse Width Modulation) control for changing the ON / OFF time ratio (Duty) with a constant ON / OFF operation cycle of the switching element SW1, and changes the ON / OFF operation cycle with a constant ON or OFF time. By performing PFM (Pulse Frequency Modulation) control or control for changing both the cycle and the duty, the current or voltage output to the load 2 is set to an arbitrary current value or voltage value.

In the configuration of FIG. 1, if attention is paid to the fact that the average value of the absolute value of the output current is equal to the power supply current measured by the shunt resistor R1, the power supply device 10 is connected to the LED with a constant current, for example. The present invention can be applied to an LED lighting device that lights up. That is, since the controller 11 can estimate the current flowing through the LED 2a or LED 2b from the power supply voltage and the power supply current flowing through the shunt resistor R1, the shunt resistor is used in the power supply device 10 used as a constant current power supply for the LED lighting device. It is sufficient for the control unit 11 to control the on / off operation of the switching element SW1 so that the current detected by R1 becomes a predetermined constant current, and when a stable voltage power source such as the DC power source 1 is used. The current flowing through the LEDs 2a and 2b does not need to be fed back to the control unit 11.
That is, it is not a problem that the lighting potentials of the LEDs 2a and 2b fluctuate in a rectangular wave shape with respect to the ground potential of the DC power supply 1, so that an LED lighting device having a simple configuration can be configured.

Of course, the current flowing through the LEDs 2a and 2b may be fed back to the control unit 11 to operate the switching element SW1.
Moreover, LED2a, 2b is not limited to a light emitting diode, It is a general term for the light source by a semiconductor, Comprising: A laser diode, an organic light emitting diode (OLED), etc. are included.
In the illustrated example, an FET (field effect transistor) is used as the switching element SW1, but a transistor, an IGBT (insulated gate bipolar transistor), or the like may be used.

  As described above, according to the first embodiment, the power supply device 10 includes the step-up power supply that uses the coil L1 and the switching element SW1 that causes a current to flow through the coil L1, and the plurality of rectifier diodes D1 to D4 that generate the output current. A capacitor C1 having one terminal connected to a connection point between the coil L1 and the switching element SW1, and the other terminal connected to the rectifier diodes D1 to D4, and a control unit 11 for operating the switching element SW1. The voltage generated at the terminal of L1 is divided by the capacitor C1, and positive and negative currents flowing through the capacitor C1 are rectified by the rectifier diodes D1 to D4 and output. Therefore, the power supply device 10 capable of outputting a wide range of voltages from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage without adding a step-down switching element and its control circuit to the step-up power supply. Can be provided. Further, even if the capacitances of the power supply and output filter capacitors are reduced, ripples superimposed on the output current, the output voltage, and the power supply current can be suppressed. Therefore, the power supply apparatus 10 having a simple configuration can be realized.

  Further, according to the first embodiment, since the LED lighting device is configured to light the LED 2a using the power supply device 10, the forward voltage of the LED 2a is changed from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage. An LED lighting device capable of lighting even with a wide range of voltages can be realized with a simple configuration.

  In addition, according to the first embodiment, the LEDs 2a and 2b that are loads are configured to also use the rectifier diodes D1 to D4 of the power supply device 10, and therefore, an LED with a simple configuration that does not use a diode for output current rectification. A lighting device can be realized.

  In the first embodiment, the case where the LED is connected as the load of the power supply apparatus 10 has been described as an example. However, the present invention is not limited to this. For example, a battery is connected as the load of the power supply apparatus 10 and the battery is connected. You may comprise the battery charger which charges.

Embodiment 2. FIG.
In the second embodiment, a transformer is provided to output an arbitrary voltage, and FIG. 8 is a circuit diagram showing a configuration example of the power supply apparatus 10 when an insulating transformer is used. 8 that are the same as or equivalent to those in FIG. 1 to FIG. In this example, the LEDs 2a and 2b serving as loads are connected to the output side of the power supply device 10, and the power supply device 10 is used as an LED lighting device.

  In FIG. 8, an insulating transformer 21 is provided on the output side of the capacitor C1 to output an arbitrary voltage. The output terminal of the capacitor C1 is connected to the primary winding of the insulating transformer 21, and the LEDs 2a and 2b that also function as a rectifier are connected to the secondary winding. The step-up voltage generated at the terminal of the coil L1 is divided by the capacitor C1 and the primary winding of the insulating transformer 21.

The insulating transformer 21 is used to adjust the output voltage according to the turn ratio of the primary winding and the secondary winding. That is, if the insulated transformer 21 in which the turn ratio is expressed by the following equation (1) is used, the output voltage supplied to the LEDs 2a and 2b as loads can be arbitrarily set.
[Output voltage (ie, secondary winding voltage) × turn ratio] ≧ [(power supply voltage) / 2] (1)

  The insulated transformer 21 simply performs voltage conversion, does not require magnetic energy to be stored in the core, and does not cause a direct current to be superimposed upon insertion of the capacitor C1, and therefore has an appropriate current capacity. It is enough if the wire can be wound. Therefore, a small core can be used, and the power supply device 10 can be downsized.

  Further, when the insulating transformer 21 is used, since the primary winding and the secondary winding are independent, the potential on the secondary side can be arbitrarily set, and the control unit 11 can output current or output voltage. Feedback control or linkage to other devices becomes easier. Further, by insulating the primary side and the secondary side, it is possible to realize the power supply device 10 that is difficult to receive an electric shock.

  In FIG. 8, only the LED 2a may be connected, and a current obtained by rectifying the output of the insulating transformer 21 using a plurality of rectifier diodes D1 to D4 as shown in FIG. In addition to the rectifier diodes D1 to D4, a current limiting coil L2 may be added as shown in FIG.

Further, for example, a single-winding transformer 22 may be used instead of the insulating transformer 21.
FIG. 9 shows a configuration example of the power supply device 10 when a single-winding transformer 22 sharing a part of the primary winding and the secondary winding is used. In this configuration example, a primary winding wound from the terminal connected to the capacitor C1 to the ground side terminal, and two windings 2 wound from the ground side terminal to the terminals connected to the rectifier diodes D5 and D6. A single-winding transformer 22 having a secondary winding is used. The secondary winding wound from the ground-side terminal of the single-winding transformer 22 to the terminal connected to the rectifier diode D5 shares a part of the primary winding, and the insulating transformer 21 is used. Compared to the case, the configuration of the transformer can be simplified. In addition, by making the primary side and secondary side potentials common, the control unit 11 can easily perform feedback control of the output current or output voltage. By this feedback control, the power supply device 10 that outputs an arbitrary voltage can be easily realized.

  In the configuration example of FIG. 9, the battery 2c is connected as a load, the outputs of the two secondary windings of the single-winding transformer 22 are rectified by rectifier diodes D5 and D6, respectively, and smoothed by the smoothing capacitor C2. It supplies to the battery 2c. By inserting the smoothing capacitor C2, ripples superimposed on the output current and the output voltage can be suppressed.

  FIG. 10 is a circuit diagram illustrating a configuration example of the power supply device 10 when the current limiting coil L2 is inserted in a path corresponding to the discharge path of the capacitor C1. Even in the power supply device 10 using the single-winding transformer 22 (or the insulating transformer 21), the inrush current can be reduced and the generation of noise can be suppressed by inserting the current limiting coil L2.

  As described above, according to the second embodiment, the power supply device 10 connects the primary winding to the output terminal of the capacitor C1, and rectifies diodes (for example, D5 and D6 in FIG. 9, D1 and D2 in FIG. 10, and 15 (D1 to D4) in FIG. 15 includes a transformer (for example, an insulating transformer 21 and a single-winding transformer 22) for connecting a secondary winding, and a voltage generated at a terminal of the coil L1 is divided by a capacitor C1 to A positive and negative polarity current that is applied to the primary winding and flows to the capacitor C1 through the transformer is converted into rectifier diodes (for example, D5 and D6 in FIG. 9, D1 and D2 in FIG. 10, and D1 to D4 in FIG. 15). ) Rectified and output. For this reason, the power supply device 10 which can output arbitrary voltages is realizable by using a transformer.

  Further, according to the second embodiment, when the insulating transformer 21 in which the primary winding and the secondary winding are independent is used, the potential on the secondary side can be arbitrarily set, and the feedback Easy to control or link to other devices. Further, by insulating the primary side and the secondary side of the transformer, it is possible to realize the power supply device 10 that is difficult to receive an electric shock.

  Further, according to the second embodiment, when the single-winding transformer 22 in which a part of the primary winding and the secondary winding is shared is used, a power supply device using a transformer with a simple configuration is used. 10 can be realized. Also, feedback control is facilitated by making the primary and secondary potentials of the transformer common.

Further, according to the second embodiment, since the battery charging device is configured to charge the battery 2c using the power supply device 10, the battery voltage ranges from a voltage lower than the power supply voltage to a voltage higher than the power supply voltage. A battery charging device that can be charged even at a voltage of 1 can be realized with a simple configuration.
Or you may comprise the LED lighting device which lights LED2a, 2b using the power supply device 10 of Embodiment 2, and in this case, the forward voltage of LED2a is lower than a power supply voltage from a power supply voltage. An LED lighting device capable of lighting even a wide range of voltages up to a high voltage can be realized with a simple configuration.

Embodiment 3 FIG.
FIG. 11 is a circuit diagram showing a configuration of power supply device 10 according to the third embodiment. In FIG. 11, the same or corresponding parts as those in FIGS. 1 to 10 are denoted by the same reference numerals, and the description thereof is omitted. Moreover, in this example, LED2a used as load is connected to the output side of the power supply device 10, and the power supply device 10 is used as an LED lighting device.

  In the third embodiment, in order to use the AC power source 1a as the power source of the power source device 10, rectifier diodes D7 to D10 that rectify the AC power source current to become DC between the AC power source 1a and the coil L1. Inserting. In this configuration, the step-up power source composed of the coil L1 and the switching element SW1 also functions as a PFC (Power Factor Correction) (power factor correction circuit).

  Further, as shown in FIGS. 12 and 13, in the power supply apparatus 10 using the AC power supply 1a, the insulating transformer 21 (or the single-winding transformer 22) is provided on the output side of the capacitor C1 as in the second embodiment. It is also possible to provide a configuration that outputs an arbitrary voltage. In the configuration example of FIG. 13, a smoothing capacitor C2 is inserted between the rectifier diodes D5 and D6 and the battery 2c to suppress ripples superimposed on the output current and output voltage.

As described above, according to the third embodiment, the power supply device 10 is inserted between the AC power supply 1a and the coil L1, and rectifies the current from the AC power supply 1a and outputs it to the coil L1 (for example, a rectifier diode). D7 to D10). Therefore, a wide range from a voltage lower than the AC power supply voltage to a voltage higher than the AC power supply voltage is added to the step-up power supply composed of the coil L1 and the switching element SW1 without adding a step-down switching element and its control circuit. Thus, it is possible to provide the power supply device 10 that can output the above voltage. Even when the AC power source 1a is used, the output current, even if the capacity of the capacitor (smoothing capacitor C2) for filtering the power source and the output is reduced, as in the case of using the DC power source 1 of the first embodiment. The ripple superimposed on the output voltage and the power supply current can be suppressed. Therefore, it is possible to realize the power supply apparatus 10 having a simple configuration, a high power factor, and using AC as a power source.
Furthermore, this power supply device 10 can be used to realize an LED lighting device and a battery charging device that use AC as a power source.

Embodiment 4 FIG.
FIG. 14 is a circuit diagram showing a configuration of power supply device 10 according to the fourth embodiment. In FIG. 14, the same or corresponding parts as in FIGS. Moreover, in this example, LED2a used as load is connected to the output side of the power supply device 10, and the power supply device 10 is used as an LED lighting device.

  In the fourth embodiment, in order to use the AC power supply 1a as the power supply of the power supply device 10, a bidirectional switching element is used as the switching element SW1 that causes a current to flow through the coil L1. The bidirectional switching element is a bidirectional switching element configured by two switching elements SW11 and SW12 connected in series, such as the switching element SW1 of FIGS. It is turned on and off simultaneously according to the signal. By using a set of bidirectional switching elements constituted by the switching elements SW11 and SW12, current can be passed and stopped in both forward and reverse directions. Therefore, the power supply apparatus 10 using the AC power supply 1a as a power supply can be configured without using the power supply rectifier diodes D7 to D10 shown in FIGS. 11 to 13 of the second embodiment.

  Further, as shown in FIG. 15, in the power supply device 10 using the AC power supply 1a, the insulation transformer 21 (or the single-winding transformer 22) is provided on the output side of the capacitor C1 as in the third embodiment. However, by using a set of bidirectional switching elements constituted by the switching elements SW11 and SW12, the rectifier diodes D7 to D10 on the power supply side can be reduced.

  In addition, it is convenient for the control unit 11 to drive the switching elements SW11 and SW12 via an insulated signal transmission circuit, and FIGS. 16 to 19 illustrate the fourth embodiment. 2 shows a configuration example of a signal transmission circuit of the power supply device 10. In addition, the control part 11 has shown only the part in connection with transmission of a drive signal.

  In the control unit 11 shown in FIG. 16, a switching element SW <b> 2 that controls the pulse transformer 31 is connected to the primary side of the pulse transformer 31. The gate terminals of the switching elements SW11 and SW12 are connected to the high potential side of the secondary winding of the pulse transformer 31, and the source terminals of the switching elements SW11 and SW12 are connected to the low potential side.

  In the control unit 11 of FIG. 16, a drive signal (on / off signal) for driving the switching elements SW11 and SW12 is input to the switching element SW2, and is transmitted to the switching elements SW11 and SW12 through the pulse transformer 31 in an insulated state. The switching elements SW11 and SW12 perform an on / off operation at the same timing.

  In the control unit 11 shown in FIG. 17, a switching element SW <b> 2 that controls the photocoupler 32 is connected to the light emitting side of the photocoupler 32. The gate terminals of the switching elements SW11 and SW12 are connected to the light receiving side of the photocoupler 32 through a gate driving unit 33. The source terminals of the switching elements SW11 and SW12 are connected to the low potential side of the insulated power supply 34. The insulated power supply 34 includes a transformer 35, a rectifier diode D11, and a smoothing capacitor C33. The drive power supply for the switching elements SW11 and SW12 is generated and supplied to the gate drive unit 33 in accordance with the control of the switching element SW3.

In the control unit 11 of FIG. 17, the switching element SW <b> 3 driven by the power source rectangular wave signal controls the insulated power supply 34 and supplies the drive power for the switching elements SW <b> 11 and SW <b> 12 to the gate drive unit 33. In addition, a drive signal (on / off signal) for controlling the operation of the switching elements SW11 and SW12 is input to the switching element SW2, and is transmitted to the switching elements SW11 and SW12 through the photocoupler 32 and the gate drive unit 33 in an insulated state. Then, the switching elements SW11 and SW12 perform the on / off operation at the same timing.
In the above, since it is assumed that one bidirectional switching element is operated, a method of operating the switching elements SW11 and SW12 constituting the one bidirectional switching element at the same timing is described. However, if the power supply current can be energized and cut off, both do not necessarily operate at the same timing. For example, the switching element on the side where the current flows through the internal parasitic diode is continuously turned on, Even if the on / off operation is performed, the same operation is performed as a whole, and the same effect can be obtained.

  16 and 17, the source terminals of the switching elements SW11 and SW12 constituting the set of bidirectional switching elements are connected to each other. However, the present invention is not limited to this, and as shown in FIGS. The drain terminals of the switching elements SW11 and SW12 may be connected. When the drain terminals are connected as shown in FIGS. 18 and 19, it is necessary to input drive signals having different potentials to the gate terminals of the switching elements SW11 and SW12. Are provided (FIG. 18), or two insulated power supplies 34 are provided so that the photocoupler 32 operates with the respective power supplies (FIG. 19).

In addition to the pulse transformer 31 and the photocoupler 32, an insulated signal transmission circuit may be configured using, for example, a signal transmission means (magnetic isolator) by magnetic coupling.
Further, in FIGS. 16 to 19, FETs are used for the switching elements SW11, SW12, SW2, and SW3. However, transistors and IGBTs may be used, and a plurality of discrete elements are combined. An element may be used.

  As described above, according to the fourth embodiment, a bidirectional switching element (for example, a set of bidirectional-compatible switching elements configured by the switching elements SW11 and SW12) is used as the switching element SW1 that allows current to flow through the coil L1. Since the configuration is adopted, the power supply side rectifier diodes D7 to D10 are not used, so that the power supply device 10 having a simpler configuration and using AC as a power source can be realized.

Embodiment 5. FIG.
FIG. 20 is a circuit diagram showing a configuration of power supply device 10 according to the fifth embodiment. In FIG. 20, the same or corresponding parts as those in FIGS. 1 to 19 are denoted by the same reference numerals and description thereof is omitted. Further, in this configuration example, a battery 2c serving as a load is connected to the output side of the power supply device 10, and the power supply device 10 is used as a battery charging device.

  In the fifth embodiment, the primary winding of the insulating transformer 21 is constituted by a plurality of windings, and a plurality of switching elements SW21, SW22, SW31, which selectively connect each winding to the capacitor C1. SW32 is provided. The switching elements SW21 and SW22 for switching connected in series constitute a set of bidirectional switching elements, and similarly, the switching elements for switching SW31 and SW32 connected in series constitute a set of bidirectional switching elements.

  The control unit 11 of the fifth embodiment has a function of outputting a switching signal for turning on / off the switching elements SW21, SW22, SW31, and SW32 for switching. The control unit 11 operates the switching elements SW21 and SW22 to be turned on and the switching elements SW31 and SW32 to be turned off by the switching signal, and applies the voltage of the capacitor C1 between the winding terminals a and c. Further, the switching signals SW21 and SW22 are turned off and the switching elements SW31 and SW32 are turned on by the switching signal to apply a voltage to the capacitor C1 between the winding terminals bc. At this time, the winding terminal a or b of the primary winding is selected and connected to the capacitor C1 so that the applied voltage has a turns ratio close to the relationship of the above formula (1). In the configuration example of FIG. 20, as the primary winding, between the winding terminals a-c is used when the power supply voltage is high, and between the winding terminals b-c when the power supply voltage is low.

  In the fifth embodiment, the efficiency is highest when the voltage between the terminals of the capacitor C1 is ½ of the power supply voltage. In order to realize the highly efficient power supply device 10, the primary winding is used. It is preferable to switch to a winding terminal having a turn ratio in which the voltage applied to the line is always close to ½ of the power supply voltage.

  For example, when the power supply apparatus 10 is applied to a battery charging apparatus as shown in FIG. 20, the control unit 11 switches the turns ratio corresponding to the power supply voltage of the AC power supply 1a (for example, 100 Vrms or 200 Vrms) having a different effective value. Or the turn ratio is changed in response to an alternating power supply voltage that changes in a sinusoidal manner. Furthermore, although the feedback path is not shown in FIG. 20, the output voltage changes depending on the charging and discharging of the capacitor C1. Correspondingly, the winding ratio may be switched. Note that the number of windings constituting the primary winding is not limited to the example of FIG. 20, and the primary winding is constituted by using more windings and the connection between the winding terminals. The output voltage may be finely controlled by switching with a large number of switching elements.

  Further, for example, in the power supply device 10 to which the DC power source 1 as shown in FIG. 8 or FIG. 9 is connected, the primary winding of the insulating transformer 21 or the single-winding transformer 22 is constituted by a plurality of windings, and the winding A switching element for switching the line ratio may be added. Also in this case, the control unit 11 can realize the highly efficient power supply device 10 by switching the winding ratio corresponding to the DC power supply 1 having different power supply voltages.

  FIG. 20 shows a configuration in which the switching elements SW11 and SW12 are used as bidirectional switching elements that allow current to flow through the coil L1 and the capacitor C1 in order to correspond to the AC power supply 1a. Instead of using a switching element, a power supply rectifier circuit (for example, rectifier diodes D7 to D10 shown in FIG. 11) and a unidirectional switching element (for example, switching element SW1 shown in FIG. 11) are provided. I do not care.

  As described above, according to the fifth embodiment, the transformer (for example, the insulating transformer 21 and the single-winding transformer 22) is configured such that the primary winding includes a plurality of windings. The switching elements (bidirectional switching elements constituted by SW21, SW22 and SW31, SW32) for selectively connecting the plurality of primary windings to the capacitor C1 are provided. For this reason, the winding ratio of the insulating transformer 21 or the single-winding transformer 22 can be switched in accordance with the power supply voltage and the output voltage, and a power supply capable of outputting a wide range of output voltage with high efficiency from a wide range of power supply voltage. The device 10 can be realized.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  DESCRIPTION OF SYMBOLS 1 DC power supply, 1a AC power supply, 2 load, 2a, 2b LED, 2c battery, 10 power supply device, 10a LED lighting device, 10b battery charging device, 11 control part, 21 insulation type transformer, 22 single winding type transformer, 31 pulses Transformer, 32 Photocoupler, 33 Gate drive, 34 Insulated power supply, 35 Transformer, C1 capacitor, C2, C3 Smoothing capacitor, D1 to D11 Rectifier diode, L1 coil, L2 Current limiting coil, R1 Shunt resistor, SW1, SW2 , SW3 switching element, SW11, SW12, SW21, SW22, SW31, SW32 Switching element constituting a bidirectional switching element.

Claims (10)

A switching type power supply device using a coil and a switching element for passing a current through the coil,
The switching element;
The coil connecting one terminal to the power supply side and connecting the other terminal to the switching element;
A plurality of rectifier diodes for generating an output current;
A capacitor connecting one terminal to a connection point of the coil and the switching element, and connecting the other terminal to the rectifier diode side;
A control unit for operating the switching element,
The rectifier diode is
An output current flows from the capacitor both when the switching element is turned on and when the switching element is turned off.
Power supply, characterized in that said higher voltage than the power supply voltage generated at the terminals of the coil divided by the capacitor, and outputs a current you flow to the condenser was rectified by the rectifier diode. A transformer that connects a primary winding to the output side terminal of the capacitor and a secondary winding to the rectifier diode;
The voltage generated at the terminals of the coil divided by the capacitor is applied to the primary winding of the transformer, the you flow in the capacitor current through the transformer to output the rectified by the rectifier diode The power supply device according to claim 1.   3. The power supply device according to claim 2, wherein the transformer is an insulating transformer in which the primary winding and the secondary winding are independent.   3. The power supply device according to claim 2, wherein the transformer is a single-winding transformer in which a part of the primary winding and the secondary winding are shared.   5. The rectifier circuit according to claim 1, further comprising a rectifier circuit that is inserted between the power source and the coil and rectifies a current from the power source and outputs the rectified current to the coil. Power supply.   The power supply apparatus according to claim 1, wherein the switching element is a bidirectional switching element or a bidirectional switching element. In the transformer, the primary winding is composed of a plurality of windings,
The power supply device according to any one of claims 2 to 4, further comprising a plurality of switching elements that selectively connect the plurality of primary windings to the capacitor.   The LED lighting device which lights LED (light emitting diode) using the power supply device in any one of Claims 1-7.   The LED lighting device according to claim 8, wherein the LED is also used as a plurality of rectifier diodes that generate an output current of the power supply device.   A battery charging device for charging a battery using the power supply device according to claim 1.

Images