JP2008125269A - Voltage step-up circuit and voltage step-down circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit capable of converting a low voltage, a large current and a high voltage, a small current to each other without using an inductance. <P>SOLUTION: When an SW2 is closed and an SW1 is opened, a charging operation is executed and a capacitor C1 is connected to a base voltage via a diode D1. As this result, the capacitor C1 is charged with the base voltage. Then, the SW2 is opened and the SW1 is closed, and a discharging operation is executed. That is, the potential of a serial circuit of the capacitor C1 and the basis voltage is extracted to the outside via a diode D2. Since the base voltage is charged to the capacitor C1, the voltage to be extracted is two times the base voltage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a step-up circuit and a step-down circuit. In particular, the present invention relates to a step-up circuit and a step-down circuit with improved conversion efficiency.

  In recent years, a booster circuit and a step-down circuit with improved performance have been demanded.

  For example, in a so-called hybrid car, a battery is used, which is about 1.2 V (nickel metal hydride) -3.7 V (lithium ion) per cell. On the other hand, in order to improve motor efficiency, the drive motor is driven with a voltage of several hundred volts.

  Therefore, in a hybrid car, it is a common practice to connect several stages of cells in series to create a power of several tens of volts and boost this to several hundred volts with a booster circuit. Therefore, the performance of the booster circuit used therein is extremely important.

  Also, for example, in recent years, processors used in personal computers have been increasing in voltage and current. However, an excessively low voltage and large current power supply device is complicated to handle such as a thick power cord. For this reason, a step-down circuit that steps down the power from the conventional power supply device in the vicinity of the processor to reduce the voltage and current is used. Therefore, the performance of this step-down circuit is extremely important.

Various techniques for improving the prior art document conversion efficiency have been proposed.

  For example, Patent Document 1 below discloses a technique for improving the efficiency of a booster circuit and a step-down circuit. A technique is disclosed in which a MOSFET is provided in parallel with a Schottky diode to eliminate the influence of a forward voltage drop of the Schottky diode.

  Further, for example, Patent Document 2 below discloses a DC-DC converter that discharges a surge voltage to the output side to improve operation efficiency.

Japanese Patent Laid-Open No. 2001-45745 JP 2006-203996 A

  Thus, many conventional booster circuits and step-down circuits mainly use inductance, and it has been difficult to achieve good efficiency in all operating states.

  An object of the present invention is to realize a mechanism capable of mutually converting a low voltage / large current and a high voltage / small current without using an inductance.

  (1) Further, in order to solve the above problems, the present invention connects the first capacitor, the basic voltage, and the first terminal of the first capacitor, and the direction from the basic voltage toward the first terminal. An upstream diode having a forward direction, a double voltage output and a first terminal of the first capacitor, an output diode having a forward direction from the first terminal to the double voltage output, A Nopen switch connecting the second terminal of the first capacitor and the basic voltage; an Nclose switch connecting the second terminal of the first capacitor and the ground; and a control circuit. A booster circuit characterized in that the Nclose switch is closed, the Nopen switch is opened, and the Nclose switch is opened and the Nopen switch is closed during discharging. .

  Since the capacitor is charged with the basic voltage and taken out in series with the basic voltage, a voltage twice as large as the basic voltage can be easily obtained.

  (2) Further, in order to solve the above-described problem, the present invention provides the first to n-th capacitor groups, the basic voltage, and the k-th (1 = <k = <n) capacitors. A first terminal to an nth upstream diode group in which the direction from the basic voltage toward the first terminal is a forward direction, the ground, and the jth (2 = <j = < n) the second terminals of the capacitors, the n-1 downstream diode groups from the second terminal to the nth, the forward direction being from the second terminal to the ground, the n-fold voltage output, An output diode connected to the first terminal of the first capacitor and having a forward direction from the first terminal toward the n-fold voltage output; and the i-th (1 = <i = <n−1) capacitor First to (n−1) th connecting the second terminal of the first and the first terminal of the (i + 1) th capacitor. A Nopen switch group comprising n-1 Nopen switches in FIG. 1 and an nth Nopen switch connecting the second terminal of the n-1 th capacitor and the basic voltage, and a first No. of the first capacitor. An Nclose switch connecting two terminals to the ground, and a control circuit, wherein the control circuit closes the Nclose switch when charging, opens the Nopen switch, opens the Nclose switch when discharging, and opens the Noclose switch Is a booster circuit characterized by closing. Here, n is a positive integer of 2 or more, and i, j, and k are positive integers.

  With such a configuration, an n + 1 voltage booster circuit can be easily configured.

  (3) Further, the present invention includes a plurality of booster circuits described in the above (1) or (2), and multiphase control in which any one of the plurality of booster circuits is sequentially discharged. A multi-phase booster circuit including the circuit.

  Since a plurality of booster circuits are provided and discharged in order, a smoother output can be obtained.

  (4) Further, in order to solve the above-described problem, the present invention provides a first capacitor, a second capacitor having a first terminal connected to the two-divided output and a second terminal connected to the ground. , An Nclose switch connecting the first terminal of the first capacitor and the divided voltage output, and a first Nopen switch connecting the second terminal of the first capacitor and the first terminal of the second capacitor. And a Nopen switch group including an input Nopen switch connecting a first terminal of the first capacitor and a basic voltage, and connecting a ground and a second terminal of the first capacitor to the second terminal from the ground. A diode having a forward direction toward the terminal, and a control circuit. The control circuit closes the Nopen switch group when charging, opens the Nclose switch, and opens the Nclose switch when discharging. Open en switches, a step-down circuit, characterized in that closing said Nclose switch.

  Since the capacitor is charged with the basic voltage and taken out in series with the basic voltage, a voltage twice as large as the basic voltage can be easily obtained.

  (5) Further, in order to solve the above-described problem, the present invention provides n-1 capacitor groups from the first to the (n-1) th and a first terminal connected to the n divided voltage output, An n-th capacitor whose terminal is connected to the ground, n-1 Nclose switch groups connecting the first terminal of the first to n-1 capacitor groups and the n-divided voltage output, and the first a group of n-1 Nopen switches each connecting a second terminal of a capacitor of k (1 = <k = <n−1) and a first terminal of the k + 1th capacitor, and a first of the first capacitor. A Nopen switch group consisting of an input Nopen switch connecting a terminal and a basic voltage, and a control circuit, wherein the control circuit closes the Nopen switch group, opens the Nclose switch, and discharges when charging. Nopen switch Open group, a step-down circuit, characterized in that closing said Nclose switch. Here, n is a positive integer of 2 or more, and k is a positive integer.

  With such a configuration, an n-divided voltage step-down circuit can be easily configured.

  (6) Further, the present invention includes a plurality of step-down circuits according to the above (4) or (5), and multiphase control for sequentially setting any step-down circuit out of the plurality of step-down circuits. A multi-phase step-down circuit including the circuit.

  Since a plurality of step-down circuits are provided and discharged in order, a smoother output can be obtained.

  (7) Further, in the multiphase booster circuit according to the above (3), the multiphase control circuit, after switching the discharge state, after placing the booster circuit to be newly placed in the discharge state into the discharge state, A multiphase booster circuit characterized in that a booster circuit that has been in a discharged state is placed in a charged state after a predetermined overlap time has elapsed.

  Since discharge is performed by overlapping, a smoother output can be obtained.

  (8) Further, the present invention provides the multiphase step-down circuit according to the above (5), wherein when the multiphase control circuit switches the discharge state, the step-down circuit to be newly placed in the discharge state is placed in the discharge state. A multi-phase step-down circuit, wherein a step-down circuit that has been in a discharged state is placed in a charged state after a predetermined overlap time has elapsed.

  Since discharge is performed by overlapping, a smoother output can be obtained.

  (9) Further, the present invention is the booster circuit according to any one of (1) to (3) above, wherein a secondary battery is used instead of the capacitor.

  (10) The present invention is the step-down circuit according to any one of (4) to (6), wherein a secondary battery is used instead of the capacitor.

  As described above, according to the present invention, it is possible to provide a circuit capable of efficient voltage step-up / step-down using a capacitor or a storage battery (secondary battery).

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

First Usage Mode FIG. 1 is an explanatory diagram showing a usage mode of the voltage multi-divide circuit 10 according to the present embodiment. The voltage multi-divide circuit 10 is supplied with electric power from the power supply 12 and outputs a boosted or stepped down voltage to the outside. The SW timing generation control circuit 14 for controlling the operation of the voltage multi-divide circuit 10 supplies a predetermined clock signal to the voltage multi-divide circuit 10. The voltage multi-divide circuit 10 and the SW timing generation control circuit 14 correspond to a preferred example of a booster circuit and a step-down circuit in the claims. In particular, the SW timing generation control circuit 14 corresponds to a preferred example of the control circuit (or multiphase control circuit) in the claims.

Second Principle In the present embodiment, boosting is realized by charging a plurality of capacitors (capacitors) in parallel and discharging in series. On the contrary, the voltage reduction is realized by charging a plurality of capacitors (capacitors) in series and discharging them in parallel.

  In order to perform such charging / discharging operations, a circuit configuration including a switch and a diode is employed in the present embodiment.

Third component The main components used in the present embodiment will be described. There are three main components: C, SW, diode, and drive circuit.

  C is a capacitor (capacitor) or a secondary battery (rechargeable battery). Various capacitors and secondary batteries are used according to the purpose and capacity. In the case of a small-capacity / low-voltage power supply, it is also preferable to use an electric double layer capacitor. In recent years, an extremely large capacity electric double layer capacitor has been obtained. Moreover, it is also suitable to utilize a nickel metal hydride rechargeable battery (secondary battery), a lithium ion rechargeable battery (secondary battery), etc. depending on a use. (Lead) storage battery may be used. In all the embodiments to be described later, for the sake of convenience, all the capacitors are described. However, a secondary battery may be used.

  SW is a switch that can be operated at high speed. Although a mechanical switch can be used, a semiconductor switch that can be easily highly integrated, such as a photo MOS relay, is generally preferable.

  A variety of conventionally known drive circuits can be used as the drive circuit for driving SW. For example, it is preferable to appropriately use a known drive circuit for driving a photo MOS relay.

  -It is considered that the diode is preferably a Schottky diode or the like having a low threshold value (saturation voltage).

Regarding the name of the fourth basic component operation In this embodiment, a plurality of capacitors are charged in parallel, and the capacitors are taken out in series and boosted. In each circuit example to be described later, examples of double voltage, triple voltage, quadruple voltage, and the like are shown, but such an operation of multiplying the voltage is a preferable example of boosting.

  In this embodiment, a plurality of capacitors are charged in series, and the capacitors are taken out in parallel to perform step-down. In each circuit example to be described later, an example of 1/2 voltage, 1/3 voltage, 1/44 voltage, etc. is shown. This is a preferred example.

  In a circuit example to be described later, a control circuit that generates a drive signal is not necessarily shown, but a circuit that outputs a signal that repeats ON / OFF alternately is widely known in the past as various power supply circuits and the like. Therefore, such a circuit may be used as appropriate.

Fifth 2x booster circuit below a specific example of the voltage multi-divide circuit, will variously described. Note that multi means an n-fold voltage booster circuit, and is a preferred example of a booster circuit. Divide means a 1 / n double voltage step-down circuit, and is a suitable example of a step-down circuit.

  First, FIG. 2 shows an example (referred to as a double voltage booster circuit) that uses one C to boost the voltage to a double voltage. As shown in this figure, the double voltage booster circuit includes one C (denoted as C1 in FIG. 2).

  The double voltage booster circuit includes an Nclose group switch SW2, and a basic voltage is applied to the capacitor C1 by the switch SW2 to be charged. The double voltage booster circuit includes a Nopen group switch SW1, and the reference voltage and the capacitor C1 are connected in series by the switch SW1 to perform boosting (see FIG. 2).

Furthermore, a diode D1 is provided to prevent backflow to the basic voltage even when the potential of the capacitor C1 becomes higher than the basic voltage. In addition, a diode D2 is provided to prevent the double voltage output voltage from flowing back to the capacitor C1 when charging the capacitor C1.
The diode D1 corresponds to a preferred example of the upstream diode in the claims. The diode D2 corresponds to a preferred example of the output diode in the claims.

  In all the present embodiments, the Nclose group corresponds to a preferable example of the Nclose switch group in the claims. A switch belonging to the Nclose group corresponds to a preferable example of the Nclose switch in the claims.

  In all the present embodiments, the Nopen group corresponds to a preferred example of the Nopen switch group in the claims. A switch belonging to the Nopen group corresponds to a preferred example of the Nopen switch in the claims.

Operation First, the switch SW2 of the Nclose group is set to the “closed” state, and the switch SW1 of the Nopen group is set to the “open” state. In this state, a basic voltage is applied to C1 and charged. For this basic voltage input, it is preferable to use a capacitor, a secondary battery or the like, but other various power sources can be used. This state is called a charged state.

  Next, the switch SW2 of the Nclose group is set to the “open” state, and the switch SW1 of the Nopen group is set to the “closed” state. In this state, C1 is connected in series with the power supply of the basic voltage. Therefore, the terminal to which the diode D2 of the capacitor C1 is connected has a potential twice as large as the basic voltage when viewed from the ground. This doubled potential (voltage) is taken out through the diode D2. This state is called a discharge state.

  By repeating such two states as described above, a voltage twice the basic voltage can be obtained. In order to repeat the two states, it is only necessary to invert the open / close state of the switches SW1 and SW2 every predetermined period. However, such control signals and drive signals are generated by an external control circuit (not shown). Do. Since a circuit for generating a signal for opening and closing the switch every predetermined period has been conventionally used in various power supply circuits, it is easy for those skilled in the art to configure such a circuit.

Sixth Triple Booster Circuit FIG. 3 shows an example (referred to as a triple booster circuit) that boosts the voltage to three times using two Cs. As shown in this figure, the triple voltage booster circuit includes two Cs (denoted as C1 and C2 in FIG. 2).

  The triple voltage booster circuit includes an Nclose group switch SW2, and a basic voltage is applied to the capacitors C1 and C2 in parallel by the switch SW2 to be charged. The triple voltage booster circuit includes Nopen group switches SW1a and SW1b, and the switches SW1a and SW1b connect the reference voltage and the capacitors C1 and C2 in series to perform boosting (see FIG. 3).

Furthermore, diodes D1a and D1b are provided for the capacitors C1 and C2 so as not to flow backward to the basic voltage even when the potential of the capacitors C1 and C2 becomes higher than the basic voltage. In addition, a diode D2 is provided to prevent the triple voltage output voltage from flowing back to the capacitor C1 when charging the capacitors C1 and C2. Further, a diode D3 is provided so that the capacitor C2 is not short-circuited even when the switch SW1a is closed.
The diodes D1a and D1b correspond to a suitable example of the upstream diode group. The diode D3 corresponds to a preferable example of the downstream diode group.

Operation First, the switch SW2 of the Nclose group is set to the “closed” state, and the switches SW1a and SW1b of the Nopen group are set to the “open” state. In this state, C1 and C2 are charged by applying a basic voltage. For this basic voltage input, various power sources can be used. This state is called a charged state.

  Next, the switch SW2 of the Nclose group is set to the “open” state, and the switches SW1a and SW1b of the Nopen group are set to the “closed” state. In this state, the two capacitors C1 and C2 are all connected in series with the power source of the basic voltage. Therefore, the terminal to which the diode D2 of the capacitor C1 is connected has a potential that is three times the basic voltage when viewed from the ground. This three times the potential (voltage) is taken out through the diode D2. This state is called a discharge state.

  By repeating the two states as described above, a voltage three times the basic voltage can be obtained. In order to repeat the two states, it is only necessary to invert the open / close state of the switches SW1 and SW2 every predetermined period. However, such control signals and drive signals are generated by an external control circuit (not shown). Do. As this control circuit, the same control circuit as that used in the circuit of FIG. 2 can be used.

The seventh 4 doubling boosting circuit 4, an example of boosting to four times the voltage by using three of the C (4 referred to as doubling boosting circuit) is shown. As shown in this figure, the quadruple voltage booster circuit includes three Cs (denoted as C1, C2, and C3 in FIG. 2).

  The quadruple voltage booster circuit includes an Nclose group switch SW2, and the basic voltage is applied to the capacitors C1, C2, and C3 in parallel by the switch SW2 and charged. The quadruple voltage booster circuit includes Nopen group switches SW1a, SW1b, and SW1c, and the switches SW1a, SW1b, and SW1c connect the reference voltage and the capacitors C1, C2, and C3 in series to boost the voltage. (See FIG. 4).

Furthermore, diodes D1a, D1b, and D1c are provided for the capacitors C1, C2, and C3 to prevent backflow to the basic voltage even when the potentials of the capacitors C1, C2, and C3 become higher than the basic voltage. Further, a diode D2 is provided to prevent the quadruple voltage output voltage from flowing back to the capacitor C1 when charging the capacitors C1, C2, and C3. Further, diodes D3a and D3b are provided so that the capacitors C2 and C3 are not short-circuited even when the switch SW1a is closed.
The diodes D1a, D1b, and D1c correspond to a preferable example of the upstream diode group in the claims. The diodes D3a and D3b correspond to a preferable example of the downstream diode group in the claims.

Operation First, the switch SW2 of the Nclose group is set to the “closed” state, and the switches SW1a, SW1b, and SW1c of the Nopen group are set to the “open” state. In this state, a basic voltage is applied to C1, C2, and C3 to be charged. For this basic voltage input, various power sources can be used. This state is called a charged state.

  Next, the switch SW2 of the Nclose group is set to the “open” state, and the switches SW1a, SW1b, and SW1c of the Nopen group are set to the “closed” state. In this state, the three capacitors C1, C2, and C3 are all connected in series with the power source of the basic voltage. Therefore, the terminal to which the diode D2 of the capacitor C1 is connected has a potential that is four times the basic voltage as viewed from the ground. Four times this potential (voltage) is taken out via the diode D2. This state is called a discharge state.

  By repeating the two states (charged state and discharged state) as described above, a voltage four times the basic voltage can be obtained. In order to repeat the two states, a control signal and a drive signal may be generated using a control circuit that reverses the open / close state of the switches SW1 and SW2 for each predetermined period described with reference to FIGS.

Eighth two-phase (multi-phase) configuration In FIGS. 2, 3, and 4 described above, boosting is performed by repeating charging and discharging. As a result, the output signal becomes a pulsating flow.

  Therefore, in order to make the output smoother, it is conceivable to obtain a smoother output by combining a plurality of booster circuits and taking a discharge state in order.

  The number of the plurality of booster circuits may be any number, but an explanatory diagram showing the principle in the case of two is shown in FIG. As shown in this figure, by connecting two n-fold voltage booster circuits (n is any of 2, 3 and 4) in parallel and alternately discharging them, the output obtained is not pulsating, It can be DC (direct current). FIG. 5 shows that the output is set to DC by synchronizing the n-fold voltage booster circuit A and the n-fold voltage booster circuit B with the output opposite phase. In other words, a common control circuit is provided for two n-fold voltage boosting circuits.

  In FIG. 5, an example of two phases is shown, but of course three or more phases are also suitable.

  In order to synchronize, a control circuit that outputs a two-phase (three or more phases) signal is necessary, but such a circuit is conventionally used in various circuits such as a switching power supply. An existing such circuit may be used.

The ninth 2 partial pressure step-down circuit 6, an example of the step-down with two C to 1/2 of the voltage (referred to as a 2-minute pressure step-down circuit) is shown. As shown in this figure, the half-voltage step-down circuit includes two Cs (denoted as C1 and C2 in FIG. 6).

  The half-voltage step-down circuit includes the Nopen group switches SW2 and SW3, and the basic voltage is applied to the series circuit of the capacitors C1 and C2 by the switches SW2 and SW3 to be charged. Further, the half-voltage step-down circuit includes an Nclose group switch SW1, and the reference voltage and the capacitor C1 are connected in parallel with the capacitor C2 by the switch SW1 to perform step-down (see FIG. 6).

  Further, a diode D1 is provided for preventing the capacitor C2 from discharging when the capacitor C2 is being charged.

Operation First, the switches SW2 and SW3 in the Nopen group are set to the “closed” state, and the switch SW1 in the Nclose group is set to the “open” state. In this state, the basic voltage is applied to the series circuit of C1 and C2 to be charged. For this basic voltage input, it is preferable to use a capacitor, a secondary battery or the like, but other various power sources can be used. This state is called a charged state.

  Next, the switch SW1 of the Nclose group is set to the “open” state, and the switches SW2 and SW3 of the Nopen group are set to the “closed” state. In this state, the parallel circuit of the capacitors C1 and C2 is connected to the divided voltage output. Therefore, a voltage that is ½ of the basic voltage appears in the divided voltage output. This state is called a discharge state.

  By repeating the two states as described above, a voltage ½ times the basic voltage can be obtained. In order to repeat the two states, the open / close state of the switch SW1 of the Nclose group and the SW2 and SW3 of the Nopen group may be reversed every predetermined period. However, such control signals and drive signals are external ( This is performed by a control circuit (not shown). As this control circuit, the control circuit as already described in FIG. 2 and the like can be used.

The tenth 3 partial pressure step-down circuit 7, an example of the step-down to 1/3 times the voltage using 3 pieces of C (referred to as 3 partial pressure step-down circuit) is shown. As shown in this figure, the three-divided voltage step-down circuit includes three Cs (denoted as C1, C2, and C3 in FIG. 7). These three capacitors C1, C2, and C3 all have the same capacitance.

  The three-divided voltage step-down circuit includes a Nopen group switch SW3, and a basic voltage is applied to the series circuit of the capacitors C1, C2, and C3 by the switch SW3 to be charged. Also, the Nopen group switch SW2a is provided between the capacitor C1 and the capacitor C2, and the same Nopen group switch SW2b is provided between the capacitor C2 and the capacitor C3, and these capacitors are connected in series. (See Figure 7)

  The three-divided voltage step-down circuit is provided with Nclose group switches SW1a and SW1b, and a parallel circuit of the three-divided voltage output and the capacitors C1, C2, and C3 is connected by the switches SW1a and SW1b to perform step-down operation ( (See FIG. 7).

  Furthermore, diodes D1 and D2 are provided to prevent the capacitors C2 and C3 from being short-circuited and discharged when the Nopen group switches SW2a and SW2b are closed (see FIG. 7).

Operation First, the switch SW3 of the Nopen group is set to the “closed” state, and the switches SW2a and SW2b of the Nopen group are also set to the “closed” state. On the other hand, the switches SW1a and SW1b of the Nclose group are set to the “open” state. In this state, the capacitors C1, C2, and C3 are connected in series, and a basic voltage is applied to the series circuit to be charged. For this basic voltage input, various power sources can be used. This state is called a charged state.

  Next, the switch SW3 of the Nopen group is set to the “open” state, and the switches SW1a and SW1b of the Nopen group are set to the “open” state. On the other hand, the switches SW1a and SW1b of the Nclose group are set to the “closed” state.

  In such a state, the three capacitors C1, C2, and C3 are connected in parallel to the three-divided voltage output. Since the capacitors C1, C2, and C3 have the same capacity, the voltage across each capacitor is 1/3 of the basic voltage. By connecting three capacitors in parallel, a voltage that is 1/3 of the basic voltage appears in the three-divided voltage output. In this way, the pressure is lowered (three-part pressure). This state is called a discharge state.

  By repeating the two states (charged state and discharged state) as described above, a voltage that is 1/3 times the basic voltage can be obtained. In order to repeat the two states, it is only necessary to reverse the open / close state of each switch every predetermined period, but such a control circuit can use the same control circuit as described above. It is.

The eleventh 4 partial pressure step-down circuit 8, an example of the step-down to 1/4 times the voltage using four C (referred to as 4 partial pressure step-down circuit) is shown. As shown in this figure, the four-divided voltage step-down circuit includes four Cs (denoted as C1, C2, C3, and C4 in FIG. 8). These four capacitors all have the same capacity.

  The quadrature voltage step-down circuit includes a Nopen group switch SW3, and a basic voltage is applied to the series circuit of the capacitors C1, C2, and C3 by the switch SW3 to be charged. Further, the switch SW2a of the Nopen group is between the capacitors C1 and C2, the switch SW2b of the same Nopen group is between the capacitors C2 and C3, and the switch SW2c of the same Nopen group is the capacitors C3 and C4. Are provided, and serve to connect these capacitors in series (see FIG. 8).

  Further, the quadrature voltage step-down circuit includes Nclose group switches SW1a, SW1b, and SW1c, and the parallel circuit of the quadrant voltage output and the capacitors C1, C2, C3, and C4 is connected by the switches SW1a, SW1b, and SW1c. Thus, the voltage is lowered (see FIG. 8).

  Furthermore, diodes D1, D2, and D3 are provided to prevent the capacitors C2, C3, and C4 from being short-circuited and discharged when the Nopen group switches SW2a, SW2b, and SW2c are closed (see FIG. (See FIG. 8).

Operation First, the switch SW3 of the Nopen group is set to the “closed” state, and the switches SW2a, SW2b, and SW2c of the Nopen group are all set to the “closed” state. On the other hand, the switches SW1a, SW1b, and SW1c in the Nclose group are set to the “open” state. In this state, the capacitors C1 and C2, C3, C4 are connected in series, and a basic voltage is applied to the series circuit to be charged. For this basic voltage input, various power sources can be used. This state is called a charged state.

  Next, the switch SW3 of the Nopen group is set to the “open” state, and the switches SW1a, SW1b, and SW1c of the Nopen group are set to the “open” state. On the other hand, the switches SW1a, SW1b, SW1c of the Nclose group are set to the “closed” state.

  In such a state, the four capacitors C1 and C2, C3, C4 are connected in parallel to the quadrature output. Since the capacitors C1, C2, C3, and C4 have the same capacitance, the voltage across each capacitor is 1/4 of the basic voltage. By connecting four capacitors in parallel, a voltage that is 1/4 of the basic voltage appears in the four-divided output. In this way, step-down (four-part pressure) is performed. This state is called a discharge state.

  By repeating the two states (charged state and discharged state) as described above, a voltage ¼ times the basic voltage can be obtained. In order to repeat the two states, it is only necessary to reverse the open / close state of each switch every predetermined period, but such a control circuit can use the same control circuit as described above. It is.

12 shows the example of the step-down circuit in FIG. 6, FIG. 7 and FIG. 8, but it is also preferable to construct a multi-phase configuration as shown in FIG. 5 by using a plurality of step-down circuits. is there.

For example, when two step-down circuits are used, the n voltage-dividing step-down circuit A and the n voltage-dividing step-down circuit B are synchronized with each other in the output reverse phase, thereby outputting alternately and obtaining a smooth direct current. Is possible. As in the case of the booster circuit described with reference to FIG. 5, it is possible to obtain a smoother direct current by increasing the number of connections to be 3 phase, 4 phase,.

13th Modification of Multiphase Connection In the example of FIG. 5 described above, a configuration in which two booster circuits are arranged side by side and discharge / charge is repeated in sequence is shown. Further, it has been described in the twelfth aspect that a similar configuration can be adopted in the step-down circuit.

  In such a multiphase connection, it is considered that a smoother output can be obtained if the outputs are overlapped for a predetermined time during repeated switching.

  For example, as shown in FIG. 5, when the n-fold voltage booster circuit A and the n-fold voltage booster circuit B are alternately discharged, the following operation is performed.

  First, the n-fold voltage booster circuit A is set to the output state, that is, the “discharge” state, and the n-fold voltage booster circuit B is set to the “charge” state.

  Next, the n-fold voltage booster circuit B is set to the “discharge” state while the n-fold voltage booster circuit A is maintained in the discharged state. This is an overlapped state, and there is a period during which the outputs of the two phases are simultaneously output during switching.

  By switching the n-fold voltage booster circuit A from the overlap state to the “charge” state, only the n-fold voltage booster circuit B is in an output state, that is, a “discharge” state. This is the discharge state of the n-fold voltage booster circuit B.

  Next, the n-fold voltage booster circuit A is set to the “discharge” state while the n-fold voltage booster circuit B is maintained in the discharged state. This is also an overlap state, and is the moment when the outputs of the two-phase circuit are output simultaneously.

  By setting the n-fold voltage booster circuit B to the “charge” state from this overlapped state, only the n-fold voltage booster circuit A is in an output state, that is, a “discharge” state. This is the discharge state of the n-fold voltage booster circuit A.

Thereafter, similar operations are sequentially repeated.

  In order to perform such an operation, a control circuit (not shown) needs to provide an overlap for each control signal when switching. This overlap is an overlap, and if there are many overlaps, the overlap time increases and a smoother output can be obtained. In this way, giving the drive signal a certain overlap time can be easily realized by adjusting the switching timing of each drive signal.

It is explanatory drawing which shows the utilization form of the voltage multi-divide circuit concerning this Embodiment. It is a circuit diagram of a double voltage booster circuit. It is a circuit diagram of a triple voltage booster circuit. It is a circuit diagram of a quadruple voltage booster circuit. It is a function explanatory view of a polyphase circuit provided with a plurality of boosting circuits. FIG. 3 is a circuit diagram of a two-divided voltage down converter. It is a circuit diagram of a 3 voltage dividing step-down circuit. It is a circuit diagram of a 4 voltage dividing step-down circuit.

Explanation of symbols

10 voltage multi-divide circuit 12 power supply 14 SW timing generation control C capacitor or secondary battery (rechargeable battery)
D Diode SW switch

Claims (10)

A first capacitor;
An upstream diode that connects a basic voltage and the first terminal of the first capacitor, and a direction from the basic voltage toward the first terminal is a forward direction;
An output diode connecting the double voltage output and the first terminal of the first capacitor, the direction from the first terminal toward the double voltage output being a forward direction;
A Nopen switch connecting the second terminal of the first capacitor and the basic voltage;
An Nclose switch connecting the second terminal of the first capacitor and ground;
A control circuit;
Including
The control circuit closes the Nclose switch and opens the Nopen switch when charging, and opens the Nclose switch and closes the Nopen switch when discharging. N capacitor groups from first to nth;
A basic voltage and a first terminal of the k-th (1 = <k = <n) capacitor are connected to each other, and a direction from the basic voltage toward the first terminal is a forward direction to nth from first to nth. Upstream diode groups,
The ground and the second terminal of the jth (2 = <j = <n) capacitor are connected to each other, and n-1 pieces from the second to the nth in which the direction from the second terminal toward the ground is the forward direction. A downstream diode group of
an output diode that connects the n-fold voltage output and the first terminal of the first capacitor, and a direction from the first terminal toward the n-fold voltage output is a forward direction;
N-1 Nopen switches from 1 to n-1 connecting the second terminal of the i-th (1 = <i = <n-1) capacitor and the first terminal of the i + 1-th capacitor; A Nopen switch group comprising an nth Nopen switch connecting the second terminal of the n-1 th capacitor and the basic voltage;
An Nclose switch connecting the second terminal of the first capacitor and ground;
A control circuit;
Including
The control circuit closes the Nclose switch and opens the Nopen switch when charging, and opens the Nclose switch and closes the Nopen switch when discharging. Here, n is a positive integer of 2 or more, and i, j, and k are positive integers. A plurality of booster circuits according to claim 1 or 2,
A polyphase control circuit that sequentially discharges any one of the plurality of booster circuits; and
A multi-phase booster circuit comprising: A first capacitor;
A second capacitor having a first terminal connected to the two-divided output and a second terminal connected to ground;
An Nclose switch connecting the first terminal of the first capacitor and the two-divided voltage output;
A first Nopen switch connecting the second terminal of the first capacitor and the first terminal of the second capacitor; and an input Nopen switch connecting the first terminal of the first capacitor and a basic voltage. A group of Nopen switches,
A diode connecting ground and the second terminal of the first capacitor, and a forward direction from the ground toward the second terminal;
A control circuit;
Including
The control circuit closes the Nopen switch group and opens the Nclose switch when charging, and opens the Nopen switch group and closes the Nclose switch when discharging. N-1 capacitor groups from the first to the (n-1) th,
An nth capacitor having a first terminal connected to the n-divided output and a second terminal connected to ground;
N-1 Nclose switch groups connecting the first terminals of the first to n-1 capacitor groups and the n divided voltage output;
A group of (n−1) Nopen switches connecting the second terminal of the kth (1 = <k = <n−1) capacitor and the first terminal of the (k + 1) th capacitor; A Nopen switch group comprising an input Nopen switch connecting the first terminal and the basic voltage;
A control circuit;
Including
The control circuit closes the Nopen switch group and opens the Nclose switch when charging, and opens the Nopen switch group and closes the Nclose switch when discharging. Here, n is a positive integer of 2 or more, and k is a positive integer. A plurality of step-down circuits according to claim 4 or 5,
Among the plurality of step-down circuits, a polyphase control circuit for sequentially setting any one step-down circuit to a discharge state;
A multi-phase step-down circuit comprising: The multiphase booster circuit according to claim 3, wherein
When switching the discharge state, the multi-phase control circuit places a boost circuit that is newly in a discharge state in a discharge state, and after a predetermined overlap time has elapsed, the boost circuit that has been in a discharge state until then is placed in a charge state. A polyphase booster circuit characterized by being placed. The multiphase step-down circuit according to claim 5,
When switching the discharge state, the multi-phase control circuit places a step-down circuit that is newly placed in the discharge state into the discharge state, and after the predetermined overlap time has elapsed, the step-down circuit that has been in the discharged state is brought into the charge state. A polyphase step-down circuit characterized by being placed. The booster circuit according to any one of claims 1 to 3,
A step-up circuit using a secondary battery instead of the capacitor. The step-down circuit according to any one of claims 4 to 6,
A step-down circuit using a secondary battery instead of the capacitor.

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