JP4346253B2 - High current push-pull type booster circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plate-like electrode structure of a push-pull type booster circuit used in a booster circuit that boosts a DC low voltage to a DC high voltage.
[0002]
[Prior art]
Since the push-pull type booster circuit ensures a high voltage output on the secondary side, a large current flows on the low voltage primary side. For this reason, in the conventional configuration such as the patent application 2000-218151 by the applicant of the present application, the spike voltage due to the back electromotive force generated when the switching element is turned off increases due to the large inductance of the primary side current circuit, The switching loss increased, the required capacity of the snubber circuit increased, the conversion efficiency between the primary input and the secondary output decreased, and the performance of the boosting power supply circuit as a whole decreased.
[0003]
[Problems to be solved by the invention]
In the push-pull type booster circuit, the present invention minimizes the primary current path that becomes a large current, minimizes the inductance of the primary current circuit, and reduces the spike voltage caused by the counter electromotive force generated when the switching element is turned off. Reduce the switching loss, reduce the required capacity of the snubber circuit, improve the conversion efficiency between the primary input and secondary output, improve the performance of the boost power supply circuit as a whole, and increase the capacity of the secondary side output Is an issue.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the invention of claim 1, a first plate-like electrode having a substantially rectangular shape including a region where the push-pull transformer is arranged at the center and a terminal portion where a capacitor is mounted on both sides, one side A pair of second plate electrodes having a substantially rectangular shape with a terminal portion for connecting a field effect transistor and a Zener diode to the part and having an area approximately half of that of the first plate electrode, a field effect transistor on both sides, A first plate having a capacitor and a third plate electrode having a terminal portion for connecting a Zener diode and having a substantially rectangular shape and an area substantially equal to the upper portion of the first plate electrode; and an electric insulating sheet. A pair of second plate electrodes are disposed below the electrode plates, a third plate electrode is disposed below the second plate electrodes, and the first, second, and third plate electrodes. With an electrical insulation sheet Gas to be insulated, and these first, second, plate-shaped electrode structure of high current push-pull type booster circuit, characterized in that to fix the third plate electrodes together by a fastening element,
[0005]
The invention according to claim 2 is characterized in that the electronic elements arranged in the first, second, and third plate-like electrode structures are arranged at geometric object positions,
[0006]
The invention according to claim 3 is characterized in that the fastening element for fixing the first, second and third plate-like electrodes is made of an electrically insulating material.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment described below is only an example, and it is easy for an engineer who has ordinary skills in this technical field to implement other embodiments without departing from the technical scope of the present invention. is there.
[0008]
FIG. 1 shows a push-pull type step-up power supply circuit according to the present invention. In FIG. 1, a primary circuit 100 surrounded by a dotted line includes a power supply 30 such as a 12V battery connected to a primary winding 20-2 of the push-pull transformer 20 and an intermediate lead B + of the primary winding, and a power supply for the B + line. There are provided electrolytic capacitors 7 connected in parallel (m in total 2m) at both ends of 30 respectively. Further, in the primary circuit 100, n field effect transistors 5 and zener diodes 6 are connected in parallel between the C1 line and the B + line of the primary winding. The source S of the field effect transistor 5 is connected to the B + line, the drain D is connected to the C1 line, the gate G is connected to a control circuit (not shown), the cathode of the Zener diode 6 is connected to the C1 line, and the anode is connected to the B + line. . As shown, the same applies to the C2 line and B + line of the primary winding. The output of the secondary winding 20-3 via the core 20-1 of the push-pull transformer 20 is supplied to the load 50 via a rectifying / smoothing circuit 40 including a rectifying element and a capacitor.
[0009]
A total of 2 m electrolytic capacitors 7 are divided into 2 m pieces to reduce the internal impedance of the battery power supply 30 and absorb noise and to cope with a large current. In the example, m = 9. A total of 2n Zener diodes 6 constitute a snubber circuit. Further, a total of 2n field effect transistors 5 are controlled and switched by a control circuit (not shown). The Zener diode 6 and the field effect transistor 5 are both divided into 2n pieces to cope with a large current. In the example, n = 8.
[0010]
2 and 3 show the power supply circuit structure. A description will be given with reference to FIGS. The plate electrode structure constituting the power supply circuit includes an upper plate electrode 1, a pair of intermediate plate electrodes 2 and 3, and a lower plate electrode 4. Each plate-like electrode is insulated by an electrical insulating sheet 8 such as an epoxy resin and is integrally fixed by a plurality of insulating bolts 10 formed of an acrylic resin or the like. The pair of intermediate plate electrodes 2 and 3 are arranged such that the terminal portions 2-1 and 3-1 on one side are exposed to the left and right of the plate electrode.
[0011]
The power source 30 uses a screw or the like for each terminal portion 1-1 and 4-2 through a hole in each terminal portion so that the upper plate electrode 1 has a positive potential and the lower plate electrode 4 has a negative potential. Connected mechanically and mechanically. The push-pull transformer 20 has a pair of E-type ferrite cores facing each other, the primary winding is wound in the center, the outer periphery of the primary winding is insulated with an insulating sheet or the like, and the upper layer such as an insulating sheet is In this configuration, the next winding is wound. The winding ends C1 and C2 of the primary winding are electrically and mechanically connected to terminals that can be screwed respectively. A terminal that can be screwed is electrically and mechanically connected to the intermediate lead-out portion B + of the primary winding. The secondary winding lead 20-3 is electrically and mechanically connected to a secondary smoothing circuit (not shown).
In the push-pull transformer 20, the intermediate lead portion B + of the primary winding is electrically and mechanically connected to a predetermined position of the upper plate electrode 1 with a bolt, and one end portion C1 of the primary winding is connected to the intermediate plate electrode 2 with a screw. The other end portion C2 of the primary winding is also electrically and mechanically connected to a predetermined position of the intermediate plate electrode 3 in the same manner.
[0012]
4 shows the single plate state of the upper plate electrode 1, FIG. 5 shows the single plate state of the pair of intermediate plate electrodes 2 and 3, and FIG. 6 shows the single plate state of the lower plate electrode 4. The upper plate-like electrode 1 includes a terminal portion 1-1 on one side, and is inserted through screw holes and terminal portions C1 and C2 for electrically and mechanically fixing the terminal portion B + of each primary winding of the transformer 20. A rectangular through-hole, and a circular and rectangular through-hole or screw hole (screw portion) such as a screw hole for integrally fixing the three plate-like electrodes 1, 2, and 3. The pair of intermediate plate-like electrodes 2 or 3 have the same shape, and are provided with a terminal part 2-1 or 3-1 on one side part, and with a similar through hole or screw hole (screw part). The lower plate-like electrode 4 includes a terminal portion 4-2 on one side and a terminal portion 4-1 on both sides, and includes a similar through hole or screw hole (screw portion).
[0013]
Returning to FIG. 2 and FIG. First, in FIG. 2, the terminals arranged on the left and right sides of the plate-like electrode are arranged on the left and right sides of the drawing and from above, the lower plate-like electrode terminal 4-1, the intermediate plate-like electrode 2 or 3, and the terminals 2-1 or 3- 1 are arranged alternately. In the circuit structure shown in FIGS. 2 and 3, the terminals and the electronic elements described below are arranged in the left and right direction (each of the source S, drain D, and gate G of the field effect transistor 5). Due to the foot arrangement, the arrangement of the electronic elements is shifted by one terminal up and down on the left and right, but this is not an essential problem and can be regarded as the right and left target arrangement). The arrangement and connection of the following electronic elements will be described only on the right side facing FIG. 2, but the same applies to the left side.
[0014]
The field effect transistor 5 is disposed outside the terminals 2-1 and 4-1 of the plate electrode, the drain D is the terminal 2-1 of the intermediate plate electrode 2, and the source S is the terminal 4 of the lower plate electrode 4. -1 is electrically connected by solder or the like and mechanically connected. The gate G is connected to a control circuit (not shown). The Zener diode 6 is disposed on the terminals 2-1 and 4-1, the cathode is electrically and mechanically connected to the terminal 2-1 together with the drain D by soldering or the like, and the anode is connected to the terminal 4-1 together with the source S. Connected in the same way. The electrolytic capacitor 7 is disposed on the upper plate electrode 4 and similarly connected between the upper plate electrode 4 and the lower plate electrode terminal 4-1. The field effect transistor 5 is in contact with and / or fixed to a heat sink via an electrically insulating and thermally conductive resin such as silicon for cooling.
[0015]
As is clear from the above description (particularly as shown in FIG. 2), the three plate-like electrodes are configured for left and right objects, and a plurality of mounted electronic elements are arranged in the center of the electrodes. 20 is placed on the subject. Accordingly, the geometric distance between the plurality of electronic elements arranged on the substantially rectangular plate electrode and the primary winding of the transformer (for example, the distance between the terminal C1 and the plurality of electronic elements on the right side) is minimized. Arrangement configuration.
[0016]
【The invention's effect】
As is apparent from the above description, according to the invention of claim 1, the primary current path of the push-pull type booster circuit is divided into the upper plate electrode 1, the pair of intermediate plate electrodes 2 or 3, and the lower plate electrode. A laminated structure consisting of three plate electrodes (busbars) consisting of four, and by arranging each electronic element on the left and right objects, the primary current path is minimized, the inductance associated with the primary current circuit is minimized, and the switching element The off-time spike voltage is reduced, the switching loss is reduced, and the efficiency is improved. The snubber circuit exhibits a sufficient effect only by connecting the Zener diode 6 between the source S and drain D of the field effect transistor 5, and a circuit in which a capacitor is connected in series with a parallel connection of a resistor and a diode of a conventional configuration. The connection between the source S and the drain D of the effect transistor 5 is not necessary. As a result, the power consumption in the snubber circuit is significantly reduced, and the power conversion efficiency (overall performance) between the primary and secondary circuits, especially at low loads, is improved.
According to the second aspect of the present invention, the electronic elements are arranged with a geometric object, circuit analysis including inductance can be easily performed, and the degree of freedom in circuit design is increased.
Furthermore, according to the invention of claim 3, the electrical insulation between the special fixing element and the plate electrode is taken into consideration by fixing the three plate electrodes by the fastening element formed of the electrically insulating material. Therefore, the assembly work can be easily performed and the assembly on the continuous production line becomes possible.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a push-pull type booster power supply circuit showing an embodiment of the present invention.
FIG. 2 is a configuration diagram of a push-pull type booster power supply according to an embodiment of the present invention.
FIG. 3 is a partial cross-sectional view of the configuration diagram shown in FIG. 2;
FIG. 4 is a front view of an upper plate electrode.
FIG. 5 is a front view of an intermediate plate electrode.
FIG. 6 is a front view of a lower plate electrode.
[Explanation of symbols]
100 Primary side circuit 1 of push-pull type step-up power supply circuit 1 Upper plate electrode 2, 3 Intermediate plate electrode 4 Lower plate electrode 5 Field effect transistor 6 Zener 7 Electrolytic capacitor 8 Electrical insulation sheet 10 Electrical insulation fastening element

Claims (3)

An area where the push-pull transformer (20) is arranged in the center and a terminal part for mounting a capacitor on both sides, a first plate electrode (1) having a substantially rectangular shape, a field effect transistor and a Zener diode on one side A pair of second plate electrodes (2), (3) having a terminal portion to be connected and having a substantially rectangular shape and an area approximately half that of the first plate electrode; a field effect transistor, a capacitor; A third plate electrode (4) having a terminal portion for connecting a Zener diode and having a substantially rectangular shape and an area substantially equal to the upper portion of the first plate electrode; and an electrical insulating sheet (8); A pair of second plate electrodes (2) and (3) are arranged below one plate electrode (1), and a third plate electrode (4) is arranged below the second plate electrode. Between these first, second, and third plate electrodes A plate-like electrode structure for a high-current push-pull type booster circuit, wherein the plate-like electrode is electrically insulated by an insulating sheet (8), and the first, second and third plate-like electrodes are integrally fixed by a fastening element. . In Claim 1, The electronic element arrange | positioned by said 1st, 2nd, 3rd plate-shaped electrode structure is arrange | positioned in a geometric object position, It is characterized by the above-mentioned. In Claim 1, The fastening element which fixes said 1st, 2nd, 3rd plate-shaped electrode is formed from an electrically insulating material, It is characterized by the above-mentioned.

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