JP2012175880A - Non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a transmission distance to a power reception side such that high-efficiency power supply from a power transmission side is possible through a simple circuit configuration using a self-excited oscillation circuit.SOLUTION: For power supply from a power transmission-side resonance part 1 to a power reception-side resonance part 2 in a non-contact manner through a transformer 3, a self-excited oscillation circuit 10 of the power transmission-side resonance part generates a voltage of resonance frequency that a capacitor C connected in parallel between a first (+) terminal T1a and a first (-) terminal T1b of a power transmission-side primary coil L1 constituting a transformer, an induction voltage is generated between a first (+) terminal T2a and a second (-) terminal T2b of a power transmission-side secondary coil L2 based upon the generated voltage, and fed back to gate sides of first and second switching elements FET1, FET2 so as to generate and apply a drain voltage by amplifying the induction voltage between the first (+) terminal and first (-) terminal of the power transmission-side primary coil. The operation thereof is repeated.

Description

  The present invention relates to a magnetic resonance type non-contact power feeding device, and more particularly to a non-contact power feeding device having a self-excited oscillation circuit.

  Conventionally, as this type of non-contact power supply device, for example, according to the electromagnetic induction-type non-contact power supply device described in Patent Document 1, a Q value representing resonance characteristics is used as a coil magnetically coupled on the power supply side. A low core transformer is used.

  Further, according to the non-contact power transmission device using the magnetic resonance phenomenon of electromagnetic induction described in Patent Document 2, the resonance frequency of the power supply side magnetic resonance coil and the resonance frequency of the power reception side coil magnetic resonance coil are exactly matched. For this purpose, a separately excited oscillation circuit is used.

JP 2000-175379 A JP 2010-154700 A

  However, in the non-contact power supply device described in Patent Document 1 described in the background art, since the Q value of the coil magnetically coupled on the power supply side is low, highly efficient power supply from the power supply (power transmission) side is possible. There is a drawback that the transmission distance to the power receiving side becomes shorter.

  On the other hand, in the non-contact power transmission device described in Patent Document 2, for example, as shown in the block diagram of FIG. 3, various circuits 501, 502, 503, 504, 505 required on the power feeding (power transmission) side are used. Among them, a control circuit 505 for accurately matching the oscillation frequency of the oscillation circuit 501 and the resonance frequency of the resonance circuit 504 is required, which not only complicates the circuit configuration but also does not perform such control. The power supply efficiency from the power feeding (power transmission) side to the power receiving side has been difficult to reduce.

  The present invention has been made to solve these problems, and based on a simple circuit configuration using a self-excited oscillation circuit, the power transmission side can provide a highly efficient power supply to the power reception side. An object of the present invention is to provide a magnetic resonance type non-contact power feeding device with an extended transmission distance.

  In order to achieve the above-described object, the non-contact power feeding device according to the first aspect of the present invention is a non-contact power feeding device that performs non-contact power supply from a power transmission side resonance unit to a power reception side resonance unit via a transformer. is there. The transformer includes a power transmission side primary coil and a power transmission side secondary coil that are magnetically coupled, and a power reception side coil for receiving power supplied from the power transmission side primary coil. The power transmission side resonance unit includes first and second voltage dividing resistors for dividing the DC voltage, and a reference circuit for applying the DC voltage to the midpoint terminal of the power transmission side primary coil in order to secure the reference of the transformer. And the output voltage of the first and second voltage dividing resistors is applied to the gate side, between the first (+) terminal and the midpoint terminal of the power transmission side primary coil, the first (−) terminal and the midpoint terminal The first and second switching elements for amplifying the respective applied voltages between the first and second switching elements and the first (+) terminal and the first (-) terminal of the power transmission side primary coil are connected in parallel. And a self-excited oscillation circuit including a capacitor. An induced voltage is generated between the second (+) terminal and the second (−) terminal of the secondary coil on the power transmission side based on the voltage generated by the capacitor constituting the self-excited oscillation circuit, and the first dielectric voltage is generated. The drain voltage is applied between the first (+) terminal and the second (−) terminal of the power transmission side primary coil by applying the feedback to the gate side of the second switching element.

  Moreover, the non-contact electric power feeder which is a 2nd aspect of this invention is a 1st aspect of this invention. WHEREIN: A power transmission side primary coil and a power transmission side secondary coil are formed with an air-core coil.

  According to the non-contact power feeding device of the present invention, the power transmission side resonance unit is formed on the basis of a simple circuit using a self-excited oscillation circuit that does not require a predetermined adjustment process to accurately match the oscillation frequency and the resonance frequency. By configuring, it is possible to extend the transmission distance from the power transmission side resonance unit to the power reception side resonance unit that enables highly efficient power supply.

  In addition, according to the non-contact power feeding device of the present invention, the self-excited oscillation circuit that constitutes the power transmission side resonance unit uses a magnetically coupled air-core coil that does not require a core / transformer, thereby expressing the resonance characteristics. The value can be increased.

FIG. 1 is an electric circuit diagram showing a specific configuration of a non-contact power feeding device according to an embodiment of the present invention. It is a figure which shows the specific pattern which actually mounted the coil applied in the non-contact electric power feeder by the Example of this invention on a printed circuit board, and FIG. 2 (A) is the one surface side of a printed circuit board. FIG. 2B is a perspective view of the pattern of the B surface, which is the other surface side of the printed circuit board, from the A surface side. FIG. 3 is a block diagram for frequency (oscillation frequency, resonance frequency) control applied in the conventional example.

  Embodiments to which the non-contact power feeding device of the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is an electric circuit diagram showing a specific configuration of a non-contact power feeding device according to an embodiment of the present invention. This non-contact power supply device supplies power to the power receiving side resonance unit 2 from the power transmission side resonance unit 1 via the transformer 3 in a contactless manner.

  The transformer 3 includes a power transmission side primary coil L1 and a power transmission side secondary coil L2 that are magnetically coupled, and a power reception side coil L2 that receives power supplied from the power transmission side primary coil L1. The primary coil L1 and the power transmission side secondary coil L2 are formed of air-core coils.

  The power transmission side resonance unit 1 includes a first voltage dividing resistor R1, R2, a second voltage dividing resistor R3, R4 and a reference circuit RFC, first and second switching elements FET1, FET2, and a (resonant) capacitor C. And a self-excited oscillation circuit 10 having.

  In the power transmission side resonance unit 10, the first voltage dividing resistors R1 and R2 and the second voltage dividing resistors R3 and R4 are used to divide the DC voltage V0 and are connected in series. The gate of the first switching element FET1 constituting the self-excited oscillation circuit 10 is connected between the piezoresistors R1 and R2. Similarly, the gate of the second switching element FET2 constituting the self-excited oscillation circuit 10 is connected between the second voltage dividing resistors R3 and R4 connected in series.

  The reference circuit RFC of the power transmission side resonance unit 1 is formed of, for example, a choke coil, and a DC voltage is applied to the midpoint terminal T1c of the power transmission side primary coil L1 constituting the transformer 3 in order to secure a reference of the transformer 3. V0 is applied.

  In the self-excited oscillation circuit 10 of the power transmission side resonance unit 1, the first switching element FET 1 is applied with the output voltage of the first voltage dividing resistors R 1 and R 2 on the gate side, and the power transmission side primary coil L 1 constituting the transformer 3. For amplifying the applied voltage between the first (+) terminal T1a and the midpoint terminal T1c to generate a drain voltage, the source at the reference potential point, and the drain at the power transmission side primary coil L1. Each is connected to a first (+) terminal T1a. The second switching element FET2 has the output voltage of the second voltage dividing resistors R3 and R4 applied to the gate side, and between the first (−) terminal T1b and the midpoint terminal T1c of the power transmission side primary coil L1. This is for amplifying the applied voltage to generate a drain voltage, the source of which is connected to the reference potential point, and the drain of which is connected to the first (-) terminal T1b of the power transmission side primary coil L1.

  In the self-excited oscillation circuit 10 of the power transmission side resonance unit 1, the capacitor C is connected in parallel between the first (+) terminal T 1 a and the first (−) terminal T 1 b of the power transmission side primary coil L 1 constituting the transformer 3. An inductive voltage is generated between the second (+) terminal T2a and the second (-) terminal T2b of the power transmission side secondary coil L2, and this dielectric voltage is used as the first and second switching elements FET1. , For applying feedback to the gate side of FET2.

  According to the non-contact power feeding device having such a configuration, the output voltage V1 obtained by dividing the DC voltage V0 via the first voltage dividing resistors R1 and R2 in the power transmission side resonance unit 1 is the first switching element. The first (+) terminal T1a and the first midpoint terminal T1c of the power transmission side primary coil L1 constituting the transformer 3 are generated by applying a drain voltage V10 which is applied to the gate of the FET1 and amplifies the output voltage V1. A predetermined drain voltage (V11 =) V10-V0 is applied between them. On the other hand, an output voltage V2 obtained by dividing the DC voltage V0 via the second voltage dividing resistors R3 and R4 is applied to the gate of the second switching element FET2, and a drain voltage V20 obtained by amplifying the output voltage V2 is obtained. As a result, a predetermined drain voltage (V21 =) V20-V0 is applied between the first (-) terminal T1b and the first middle point terminal T1c of the power transmission side primary coil 30.

  Further, according to the self-excited oscillation circuit 10 of the power transmission side resonance unit 1, the power transmission side primary coil L 1 constituting the transformer 3 is connected in parallel between the first (+) terminal T 1 a and the first (−) terminal T 1 b. The resonance frequency voltage of the capacitor C is generated, and an induced voltage is generated between the first (+) terminal T2a and the second (-) terminal T2b of the power transmission side secondary coil L2 based on this voltage. By applying feedback to the gate sides of the first and second switching elements FET1 and FET2, the above-described between the first (+) terminal T1a and the first (−) terminal T1b of the power transmission side primary coil L1. Drain voltages V11 and V21 can be applied, and by repeating such an operation, a stable self-excited oscillation operation is possible.

  By including the self-excited oscillation circuit 10 having a configuration apparent from the above description in the power transmission side resonance unit 1 and forming the power transmission side primary coil L1 and the power transmission side secondary coil L2 constituting the transformer 3 with air core coils, Not only can the Q value representing the resonance characteristic be increased, but also a simple control function (control circuit 505) for accurately matching the oscillation frequency and the resonance frequency on the power transmission side as shown in FIG. 3 is not required. Based on the circuit configuration, it is possible to extend the transmission distance when enabling high-efficiency power supply in a non-contact manner from the power transmission side resonance unit 1 to the power reception side resonance unit 2 via the transformer 3.

  In addition, since the capacitor C is connected in parallel between the first (+) terminal T1a and the first (−) terminal T1b of the power transmission side primary coil L1, any resonance can be achieved while increasing the Q value representing the resonance characteristics. The frequency can be selected.

  The power transmission side primary coil L1 and the power transmission side secondary coil L2 constituting the transformer 3 as described above are air-core coils mounted on the printed circuit board P1 in the pattern shown in FIGS. 2 (A) and 2 (B). 2A is a pattern diagram of the A surface that is one surface of the printed circuit board P1, and FIG. 2B is a pattern of the B surface that is the other surface of the printed circuit board P1 from the A surface side. FIG.

  A power transmission side primary coil L1 that is electrically connected between the first (+) terminal T1a and the first (-) terminal T1b is mounted on the A surface of the printed circuit board P1 shown in FIG. Specifically, starting from the first (+) terminal T1a, the coil line length is expanded from the concentric outer circumference toward the inner circumference every half of the circumference to the first middle point T10 of the coil line length, and from the first middle point T10. A first turn that is concentrically deployed halfway and a first (−) terminal T1b starting from the first (−) terminal T1b are wired from the outer periphery of the concentric portion toward the inner periphery and connected to the first intermediate point T10. And a second pattern having a second turn.

  In the first pattern of the primary coil L1 on the power transmission side, the portion where the line starting from the first (+) terminal T1a and the line starting from the first (−) terminal T1b cross over is through. It is provided on the B surface which is the other surface side of the printed circuit board P1 through the hole H1, and as described above, the number of turns of the primary coil L1 on the power transmission side is formed with “2” corresponding to the number of turns. Therefore, the first (+) terminal T1a and the first (−) terminal T1b can be mounted at close positions, and the Q value representing the resonance characteristics that change with the development of the first pattern is deteriorated. It can be easily prevented.

  Further, according to the first pattern of the power transmission side primary coil L1, since the pattern is developed only on one side such as the A side of the printed circuit board P1, the stray capacitance can be kept small, and the self-resonant frequency is increased. By doing so, a wide range of usable frequencies can be set.

  The power transmission side primary coil L1 has the same distance from the first (+) terminal T1a to the first intermediate point T10 and the distance from the first (−) terminal T1b to the first intermediate point T10. Since the first (+) terminal and the first (−) terminal are formed in a symmetrical structure by a line Ln concentric with the first intermediate point T10 of the first (−) terminal, the resistance component and the inductance component are equivalent to each other. A typical midpoint terminal T1c can be provided.

  In the primary coil L1 on the power transmission side, a pattern is formed on the B surface of the printed board P1 between the first intermediate point T10 and the midpoint terminal T1c described above via the through hole H2.

  On the other hand, a power transmission side secondary coil L2 that is electrically connected between the second (+) terminal T2a and the second (−) terminal T2b is mounted on the B surface of the printed circuit board P1 shown in FIG. Specifically, with the second (+) terminal T2a as the starting point, the coil line length extends from the concentric outer circumference toward the inner circumference every half circumference to the second intermediate point T20 of the coil line length, and the second intermediate A third turn developed concentrically from the point T20, and a second intermediate point T20 wired from the concentric outer circumference to the inner circumference every half circumference starting from the second (−) terminal T2b. And a second pattern having a fourth turn connected to the second coil. According to the link coil L2, the number of turns “2” resulting from the number of turns of the third and fourth turns described above is provided. It is formed with.

  In the second pattern of the power transmission side secondary coil L2, the portion where the line starting from the second (+) terminal T2a and the line starting from the second (−) terminal T2b cross over is as follows: Since it is provided on the A surface of the printed circuit board P1 through the through hole H3, and the number of turns of the power transmission side secondary coil L2 is “2” corresponding to the number of turns as described above, The second (+) terminal T2a and the second (-) terminal T2b can be mounted in close proximity, and deterioration of the Q value representing the resonance characteristics that change with the development of the second pattern can be easily prevented. It becomes.

  Moreover, according to the second pattern of the secondary coil L2 on the power transmission side, since the pattern is developed only on one side such as the B side of the printed circuit board P1, the stray capacitance can be reduced, and the self-resonant frequency can be reduced. By increasing the frequency range, the usable frequency range can be set wide.

  As is clear from the above description, the power transmission side primary coil L1 having the first pattern and the power transmission side secondary coil L2 having the second pattern are respectively crossed on the A surface and the B surface of the printed circuit board P1. Since it can be mounted at a position that does not exceed, this printed board P1 can be realized by the board having one layer and two surfaces, and the coil can be mounted at a low manufacturing cost.

  The non-contact power feeding device of the present invention has been described with a specific embodiment. However, the present invention is not limited to this embodiment. As long as the effect of the present invention is achieved, the device of any configuration known so far can be used. It goes without saying that even if there is, it can be adopted.

  For example, according to the embodiment of the present invention, the coil having the number of turns “2” is applied as the number of turns of the power transmission side primary coil L1 (mounted on side A of the printed circuit board P1). The number of turns is not limited, and the number of turns may be an even number of 2 or more.

DESCRIPTION OF SYMBOLS 1 ... Power transmission side resonance part 10 ... Self-excited oscillation circuit C ... Capacitor R1, R2 ... 1st voltage-dividing resistor R3, R4 ... 2nd voltage-dividing resistor RFC ... Reference circuit FET1 ... 1st Switching element FET2 …… Second switching element 2 …… Receiving side resonance part 3 …… Transformer L1 …… Transmission side primary coil T1a …… First (+) terminal T1b …… First (−) terminal T1c …… Middle point L2 …… Secondary coil on power transmission side T2a …… Second (+) terminal T2b …… Second (−) terminal L3 …… Transformer on receiving side

Claims (2)

A non-contact power feeding device that performs non-contact power supply from a power transmission side resonance unit (1) to a power reception side resonance unit (2) via a transformer (3),
The transformer includes a power transmission side primary coil (L1) and a power transmission side secondary coil (L2) that are magnetically coupled, and a power reception side coil (L3) for receiving power transmitted from the power transmission side primary coil. And
The power transmission side resonance unit includes first and second voltage dividing resistors (R1, R2, R3, R4) for dividing a DC voltage (V0), and the power transmission side primary for securing a reference for the transformer. A reference circuit (RFC) for applying the DC voltage to the middle point terminal (T1c) of the coil, and output voltages of the first and second voltage dividing resistors are applied to the gate side, and the power transmission side primary coil A first voltage for amplifying the applied voltage between the first (+) terminal (T1a) and the midpoint terminal and between the first (−) terminal (T1b) and the midpoint terminal to generate a drain voltage. 1, a self-excited oscillation circuit (10) composed of a second switching element (FET1, FET2), a capacitor (C) connected in parallel between the (+) terminal and the (−) terminal of the power transmission side primary coil. )
An induced voltage between the second (+) terminal (T2a) and the second (-) terminal (T2b) of the secondary coil on the power transmission side based on the voltage generated by the capacitor constituting the self-excited oscillation circuit And applying the dielectric voltage to the gate sides of the first and second switching elements by feedback, the drain voltage between the (+) terminal and the (−) terminal of the power transmission side primary coil. A non-contact power feeding device characterized by applying   The contactless power feeding device according to claim 1, wherein the power transmission side primary coil and the power transmission side secondary coil are formed of air-core coils.

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