JP2005142458A - Wire-wound transformer and power source device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a multiple output of a wire-wound transformer with a simple structure. <P>SOLUTION: A primary wire and a plurality of secondary wires are wound on a bobbin into which a core is inserted, and each of the secondary wires is constituted of a plurality of lines overlapped on each other in parallel to constitute the wire-wound transformer of one input and plural outputs by the primary wire and the secondary wires. The primary wire of the wire-wound transformer is connected to a resonance capacitor to provide a primary side resonance circuit. This primary side resonance circuit is connected to an inverter circuit which outputs an AC signal which resonates with this resonance circuit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a winding-type high-voltage output transformer suitable for multiple outputs used for an inverter or the like for driving a cold cathode fluorescent lamp and the like, and a power supply device using the high-voltage winding-type output transformer.

Conventionally, in a ballastless type discharge lamp lighting circuit using a 1-input 2-output type multi-lamp type leakage transformer, both ends of one secondary winding are connected to both ends of the discharge lamp via a ground wire, and the other Similarly, the secondary winding is connected to both ends of another discharge lamp via a ground line, and a DC / AC inverter circuit that can simultaneously drive two discharge lamps for one input is provided. Known (for example, see Patent Document 1).
JP 2002-075756 (paragraph 0012, FIG. 11)

Conventionally, in a winding output transformer, when a plurality of outputs are configured on the secondary side, there is a problem that the structure becomes complicated as shown in Patent Document 1.
The present invention aims to solve the above problems.

In order to achieve the above object, the present invention provides a winding transformer in which a primary winding and a secondary winding are mounted on a bobbin in which a core is inserted, and a plurality of the secondary windings are stacked in parallel. It is composed of
Further, the present invention is a multi-output winding transformer in which a primary winding and a plurality of secondary windings are mounted on a bobbin having a core inserted therein, wherein the secondary windings are stacked in parallel. It is composed of lines.
Further, the present invention provides a primary winding and a plurality of secondary windings that are mounted on a bobbin in which a core is inserted, and each secondary winding is composed of a plurality of wires stacked in parallel with each other. The secondary winding constitutes a multi-output winding transformer, a resonance capacitor is connected to the primary winding of the winding transformer to provide a primary resonance circuit, and the primary resonance circuit resonates with the resonance circuit. An inverter circuit that outputs an alternating current signal is connected. Is.

  The present invention can realize a plurality of outputs of a winding transformer for high voltage output with a simple configuration.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
In FIG. 1, reference numeral 182 denotes a core, and two U-shaped cores are joined to form a square-shaped core. A primary bobbin 184 is fitted and disposed in one of the parallel portions of the core 182. A terminal block 186 is fixed at the center of the primary bobbin 184, and primary input terminals 188 and 190 are provided on the terminal block 186. A primary winding 192 is mounted on the bobbin 184, and both ends of the primary winding 192 are connected to primary input terminals 188 and 190 via lead wires.

  On the outside of the primary bobbin 184, a pair of secondary bobbins 191 and 194 are fitted and arranged on both sides of the terminal block 186. The partitions 196 at each end of the secondary bobbins 191 and 194 are in contact with both side surfaces of the terminal block 186. In FIG. 1, the partitions 196 of the secondary bobbins 191 and 194 are not shown in order to avoid complication of the drawing. Secondary windings 198 and 200 are wound around the secondary bobbins 191 and 194 by two double wires a and b. The winding start ends of the secondary windings 198 and 200 made of double wires are secondary high voltage terminals 206 and 208 provided on the terminal blocks 202 and 204 of the secondary bobbins 191 and 194 via lead wires. 210, 212, and the winding end ends are connected to ground terminals 214, 216, 218, 220 via lead wires.

  In the above-described configuration, the relationship between the primary winding 192 and the secondary windings 198 and 200 is simple because the secondary windings 198 and 200 are disposed on both sides of the primary winding in the two-layer structure of the bobbin. Multiple outputs can be configured with a simple structure. In the present embodiment, a high voltage is applied to the double parallel lines constituting the secondary winding. However, since these high voltages are at the same potential, there is no short circuit or leakage of current between the parallel secondary windings. Absent. In addition, the other parallel portion 182a of the core 182 can also have the same configuration, and in the case of this vertically symmetric structure, the primary side is connected in series or in parallel to provide one input and 8 outputs can be realized. . Further, when the number of windings of the secondary winding is 3 or 4, etc., more outputs can be achieved.

The multi-output winding transformer 44 of the above embodiment shown in FIG. 1 is driven by a self-excited oscillation circuit shown in FIG. When a winding transformer having a multi-output structure is configured by parallel winding, it is not particularly limited to the two-layer structure of the bobbin, but a multi-output type winding transformer having a secondary winding as a parallel winding on a bobbin having a normal structure. Can be configured.
Next, a power supply device that drives a 1-input 8-output winding transformer by a full-bridge self-excited oscillation circuit will be described with reference to FIG.

  In FIG. 3, reference numerals 52, 54, 56 and 58 denote FET switching elements, and commutation diodes 60, 62, 64 and 66 are connected between the sources and drains of the respective switching elements. Gate control circuits 68, 70, 72, 74 are connected to the gates of the switching elements 52, 54, 56, 58. Of these, the gate control circuits 68, 72 are connected to the PWM control circuit 76 for gate control. The circuits 70 and 74 are connected to the logic circuit 78. The PWM control circuit 76 receives a signal from the tube current detection circuit 80 that detects the current flowing through the lamp 46, and sets the conduction angle of the switching elements 52 and 56 so that the level of this signal becomes the set value given from the line 82. Control.

  Reference numeral 44 denotes a 1-input 8-output type wound transformer fixed on a substrate (not shown), and four pairs of lamps L1, L2, L3, and L4 in which two cold cathode fluorescent lamps 46 are connected in series. It is prepared. One end of each of the lamp pairs L1, L2, L3, and L4 is connected to the high-voltage terminal side of the corresponding pair of secondary windings of the wound transformer 44, respectively. One end of each of the secondary side windings S1, S3, S5, and S7 is grounded via a current detection resistor RS, and the secondary side windings S2, S4, S6, and S8 are grounded via a lead wire. . As shown in FIG. 4, one end of each resistor RS is connected to the tube current detection circuit 80 via a DC blocking capacitor C and a rectifying diode D1.

  In addition, one end of each resistor RS is connected to the inverting input terminals of the comparators 2, 4, 6 and 8 having open collector type output terminals corresponding to each other through the capacitor C and the rectifying diode D2. A threshold voltage divided by a resistor from a positive power source is applied to the non-inverting input terminals of the comparators 2, 4, 6, and 8. The comparators 2, 4, 6, and 8 having the open collector type output terminal are turned off when the potential of the inverting input terminal is higher than the threshold value of the non-inverting input terminal. When the internal impedance becomes a very large value and the potential of the inverting input terminal is lower than the threshold value of the non-inverting input terminal, the output terminal is set to an on state.

  The output terminals of the comparators 2, 4, 6, and 8 are connected in parallel to the lead wire 10 as shown in the figure. One of the output lead wires 10 is connected to a positive power supply terminal, and the other is grounded via a malfunction prevention circuit 14 comprising a CR time constant circuit of resistors and capacitors and a semiconductor switching element 12. The output lead wire 10 is connected to the lamp open detection circuit 90 and the start-up compensation circuit 88 through the lead wire 16 connected thereto.

  The phase detection circuit 51 is connected to the midpoint P of the LC series resonance circuit via the lead wire 27. The logic circuit 78 generates a signal for turning on and off the switching element based on the primary resonance phase signal from the phase detection circuit 51 connected to the lead wire 27, and the gate control circuit 68 via the PWM control circuit 76. 72, an on / off control signal is sent to the gate control circuits 70, 74, and an on / off control signal is sent to the gate control circuits 70, 74. The phase detection circuit 51 supplies a correction phase signal delayed by 90 degrees from the phase voltage signal at the midpoint P of the LC series resonance circuit to the logic circuit 78. This signal has the same phase as the current flowing through the primary side LC series resonance circuit. Even if the charging voltage of the capacitor CT reaches the DC power supply voltage, the current flowing in the primary side series resonance circuit exceeds 0V after the phase time of 90 degrees is electrically passed. It further decreases, and further reaches a negative maximum value after a phase time of 90 degrees elapses.

  At this time, since the signal delayed by 90 degrees from this voltage becomes 0 V, the switching control signal is turned on and off at this timing. In this way, the logic circuit 78 alternately outputs the switching control signal. The logic circuit 78 creates a dimming control signal based on the output signal of the dimming control circuit 84 to which the dimming signal is inputted, and the burst control and PWM control circuit 76 for switching on and off the switching element by the dimming control signal. The switch-on pulse width is controlled to keep the brightness of the lamps 46 and 46 constant, and based on the dimming signal, the brightness can be set to an arbitrary value from zero to 100%. Further, an overcurrent detection circuit 86 is connected to the logic circuit 78, and when an overcurrent flows through the lamp 20, the logic circuit 78 detects this and sends a signal for preventing the overcurrent to the PWM control circuit 76. It is configured to prevent current.

  The start-up compensation circuit 88 is connected to the shunt resistor RS of the energization circuit of the lamp 46 so that the current signal of each lamp pair is input. The start-up compensation circuit 88 inputs a start-up compensation signal to the phase detection circuit 51 so that the self-excited oscillation circuit starts up reliably when the power is turned on / off. The phase detection circuit 51 receives this start compensation signal and outputs a start signal for self-excited oscillation to the logic circuit 78. The start-up compensation circuit 88 may not start the discharge of the lamp 46 even when the phase-corrected signal from the phase detection circuit 51 enters the logic circuit 78 and the current flows to the transformer primary side in the direction determined by the logic. . The start-up compensation circuit 88 is provided for start-up compensation in such a case. In this case, in order to surely turn on the lamp 46, the start compensation circuit 88 detects the current flowing through the lamp 46 to determine whether the lamp 46 is turned on. A compensation signal is sent to the phase detection circuit 51.

  The phase detection circuit 51 receives the activation compensation signal and outputs the activation signal to the logic circuit 78 until the lamp 46 is turned on. In the dimming control circuit 84, the voltage of the dimming signal input is compared with the output voltage of the built-in triangular wave oscillation circuit to generate a burst dimming signal having a predetermined period. In accordance with the duty cycle of this signal, the overall logic signal is turned on and off to control the brightness as a result. This method can be freely adjusted from extinction to full lighting. However, since the lamp 46 is turned on and off at the cycle of the dimming signal, it is necessary to confirm the activation and surely activate every cycle. . Therefore, the start compensation circuit 88 first sends a start compensation signal to the phase detection circuit 51 in order to realize reliable lighting as described above. The start-up compensation operation will be described. When the power is turned on for the first time or when the lamp is not lit, for example, the switching elements 52 and 58 are turned on with a predetermined pulse width so that the current flows in the direction I1. .

  As a result, a current flows through the primary winding of the capacitor CT and the transformer 44, a signal enters the phase detection circuit 51 through the lead wire 27, a current flows alternately with I2, I1, I2, and I1, and the self-excited oscillation circuit detects Oscillation starts at the resonance frequency. The start-up compensation circuit 88 also makes an initial reset (at start-up) of the logic circuit 78. If the lamp does not light up, the resetting is performed again, and the first start signal is sent to the logic circuit 78 through the phase detection circuit 51. The lamp open detection circuit 90 is connected to each shunt resistor RS on the secondary side of the winding transformer 44 and detects the tube current on the secondary side. When the lamp 46 is turned off and no tube current flows, that is, when the lamp is open, a signal is sent to the logic circuit 78 through the phase detection circuit 51, and the logic circuit 78, the PWM control circuit 76, and the gate control circuits 68, 70, 72, The control circuit composed of 74 is cut off. The overcurrent detection circuit 86 sends a signal to the logic circuit 78 to shut off the control circuit when the PWM control circuit 76 is defective or the wiring of the lamp 46 is short-circuited.

  In the above configuration, when the power switch is turned on and an ON signal is instantaneously supplied from any of the PWM control circuit 76 and the logic circuit 78 to any one of the gate control circuits 68, 74 or 72, 70, the DC power supply is switched to the switching element. A current flows through the primary winding of the wound transformer 10 in the direction of I1 through 52 and 58 or in the direction of I2 through the switching elements 56 and. As a result, the self-excited oscillation circuit is activated, and the wound transformer 44 generates a resonance voltage. The frequency of the resonance voltage on the primary side of the wound transformer 44 is supplied to the phase detection circuit 51 through the lead wire 27. The logic circuit 78 and the PWM control circuit 76 drive the gate control circuits 68, 70, 72, 74 based on the phase signal from the phase detection circuit 51, and turn on / off the switching elements 52, 54, 56, 58.

  As the switching elements 52, 54, 56, and 58 are turned on and off, current flows alternately in the directions of I 1 and I 2, and the self-excited oscillation circuit self-oscillates at the primary resonance frequency of the wound transformer 10. Since the high voltage of the secondary side winding of the transformer is applied to each end electrode of each lamp pair L1, L2, L3, L4, the brightness does not vary. The rectifier diode D1 that detects the magnitude of the lamp tube current outputs a direct current signal corresponding to the current flowing through the lamp pairs L1, L2, L3, and L4, and is a lead in which the output current of each rectifier diode D1 is added. The current flowing through the line 18 is smoothed by the smoothing circuit, appears on the downstream side of the lead wire 18 as a voltage signal representing the magnitude of the tube current, and is input to the tube current detection circuit 80. .

  The output signals of the rectifier diodes D1 are usually substantially the same, and the voltage signal appearing downstream of the lead wire 18 is substantially constant. When the output signal increases in at least one of the rectifier diodes D1, this increase appears on the lead wire 18, and the tube current detection circuit 80 detects this increase phenomenon. That is, the rectifier diode D1 constitutes a wired OR circuit in the analog circuit. On the other hand, while the lamp is lit, the output terminals of the comparators 2, 4, 6, and 8 are in the OFF state, and the lead wire 10 is in the Hi state due to the voltage supplied from the positive power supply terminal. When the inverter circuit is driven, for example, when the lamp of the lamp pair L1 is cut off and no current flows through the shunt resistor RS connected to the lamp pair L1, the voltage across the shunt resistor RS becomes zero, and the output of the corresponding rectifier diode D2 The current becomes zero.

  As a result, the potential of the inverting input terminal of the comparator 2 becomes lower than the threshold value, and the output terminal of the comparator 2 is turned on. When the output terminal of the comparator 2 is turned on, the lead wire 10 is grounded through the comparator 2, the voltage is lowered, and the lead wire 10 is in a low state. This Low signal is supplied to a lamp open detection circuit 90 of the inverter circuit, from which a lamp open signal is output. In the present embodiment, as described above, a resonance voltage higher than the input power supply voltage can be obtained on the primary side of the winding transformer, so that the number of windings on the secondary side of the winding transformer can be reduced, and the winding side is used for the winding on the secondary side. There is room for space. By increasing this space, two or more parallel windings are possible, and multiple outputs can be realized. Therefore, the winding transformer used in the present invention can be a one-input multiple-output winding transformer having almost the same size as a normal one-input one-output winding transformer.

It is explanatory drawing which abbreviate | omitted a part of winding type | mold transformer of this invention. It is decomposition | disassembly external appearance explanatory drawing same as the above. It is a block circuit diagram of the power supply device of this invention. It is a block circuit diagram of a part of a power supply device.

Explanation of symbols

2 Comparator
4 Comparator
6 Comparator 8 Comparator 10 Lead Wire 12 Semiconductor Switching Element 14 Malfunction Prevention Circuit 16 Lead Wire 18 Lead Wire 44 Winding Transformer 46 Cold Cathode Fluorescent Lamp 48 Resistor 50 Malfunction Prevention Circuit 51 Phase Difference Generation Circuit 52 to 58 Switching Element 62 to 58 66 commutation diode 68 gate control circuit 70 gate control circuit 72 gate control circuit 74 gate control circuit 76 PWM control circuit 78 logic circuit 80 rectification control circuit 82 line 84 dimming control circuit 86 overcurrent detection circuit 88 start compensation circuit 90 lamp open Short detection circuit 184 Bobbin 186 Terminal block 188 Input terminal 190 Input terminal 192 Bobbin 194 Bobbin 196 Partition 198 Secondary winding 200 Secondary winding 202 Terminal block 204 Terminal block 206 High voltage terminal 208 High voltage terminal 21 High-voltage terminal 212 the high-voltage terminal 214 ground terminal 216 ground terminal 218 ground terminal 220 ground terminal

Claims (3)

  A winding-type transformer in which a primary winding and a secondary winding are mounted on a bobbin in which a core is inserted, wherein the winding is characterized in that the secondary winding is constituted by a plurality of parallelly stacked wires. Trance.   A multi-output winding type transformer in which a primary winding and a plurality of secondary windings are mounted on a bobbin in which a core is inserted, and the secondary winding is constituted by a plurality of parallelly stacked wires. A winding transformer for multiple outputs. A primary winding and a plurality of secondary windings are mounted on a bobbin in which a core is inserted, and each of the secondary windings is configured by a plurality of wires stacked in parallel to each other. To form a multiple output winding transformer, connect a resonance capacitor to the primary winding of the winding transformer, provide a primary resonance circuit, and output an AC signal that resonates with the resonance circuit to the primary resonance circuit A power supply device characterized by connecting an inverter circuit.

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