JPH0523790U - Power circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] In the resonance type power supply circuit, most of the circuit parts are integrated into HIC to reduce the size by adding capacitors and inductances that are not suitable for integration, and the constants of external parts. The versatility is enhanced by making it possible to arbitrarily select. [Structure] A series resonance circuit 4 and a parallel resonance circuit 5, and a switching element S for switching a current flowing through these resonance circuits.
1, a switching unit 2 having S2, and a timing control unit 6 for controlling the operation timing of the switching element.
A resonance type power supply circuit that generates series resonance with respect to a current during an ON period of the switching element and generates parallel resonance with respect to a voltage during an OFF period of the switching element. Resonance capacitors C1 and C2 and inductances U1 to U3 of the circuit and the parallel resonance circuit, and switching frequency setting capacitors C10, C11, C12 and C2 of the timing controller.
0, C21, C22 are externally attached, and the remaining portion is the hybrid integrated circuit configuration 100.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is a low-noise, high-efficiency resonant power supply useful for audio equipment and the like, which is partially miniaturized by HIC (hybrid integrated circuit), and has a large capacity, high withstand voltage capacitor, and inductance not suitable for integration. This is related to the power supply circuit that has improved versatility by externally connecting.

[0002]

[Prior Art]

 In the field of audio equipment, which is becoming more multifunctional and smaller, the appearance of the device becomes larger when the power supply circuit is made up of discrete parts. Therefore, recently, a hybrid integrated circuit (HIC) is used to make the device smaller. Tend to do. As is well known, HIC is a combination of active elements such as transistors and diodes, passive elements such as resistors and capacitors, and ICs and LSIs on a substrate composed of thin and thick films. Compared to a discreet circuit, it can be sufficiently miniaturized and is highly reliable in terms of earthquake resistance.

[0003]

[Problems to be solved by the device]

 However, since the resonant power supply performs series resonance or parallel resonance, a capacitor and inductance are indispensable in its configuration, and components other than the resonance circuit, such as capacitors, are not easily integrated. Doing it is unavoidable. In this invention, in the above-mentioned resonant power supply circuit, most of the circuit part is made into a HIC to achieve miniaturization by externally attaching capacitors and inductances that are not suitable for integration, and the constants of external parts can be set arbitrarily. The purpose is to increase versatility by making it selectable.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a series resonance circuit and a parallel resonance circuit, a switching unit having a switching element for switching a current flowing through these resonance circuits, and a timing control unit for controlling the operation timing of the switching element. A resonance type power supply circuit that causes series resonance with respect to current during the ON period of the switching element and parallel resonance with respect to voltage during the OFF period of the switching element. The resonance capacitor and the inductance of the resonance circuit and the parallel resonance circuit, and the switching frequency setting capacitor of the timing control unit are externally provided, and the remaining part has a hybrid integrated circuit configuration.

[0005]

[Action]

 A resonant power supply that achieves high efficiency and low noise by utilizing current resonance and voltage resonance requires series and parallel resonant circuits and switching circuits, and these circuits require capacitors and inductances. use. In this device, a switching frequency setting capacitor with a low withstand voltage and a large capacitance, a parallel resonance capacitor with a low capacitance but a high withstand voltage, and a series resonance capacitor that is indispensable in the circuit configuration are suitable for integration. The resonance and feedback inductances that are not included are externally attached, and the partial circuit that is composed of other semiconductor elements and resistors is integrated into a HIC. Realize a general-purpose power supply by arbitrarily setting the component constants.

[0006]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a main part of a power supply circuit according to an embodiment of the present invention. The entire power supply circuit shown in this embodiment is of a switching inverter type using voltage resonance and current resonance, and has been filed by the applicant as Japanese Patent Application No. 3-166383. First, the principle configuration of this power supply device will be described with reference to FIG. In this figure, 1 is a DC power supply, 2 is a main switching element that can be turned on and off at an arbitrary timing, switching means for switching the DC power supply 1 to convert it into AC, and 3 is all AC input supplied. DC output means for wave rectifying and smoothing with a capacitor to produce a DC output, 4 is a series resonance circuit formed in series with the current flowing through the output terminal of the switching means 2, and 5 is generated at the output terminal of the switching means 2. A parallel resonance means formed in parallel with the voltage, and 6 is a timing control means having a drive element for intermittently turning on the switching element of the switching means 2.

FIG. 3 is a basic principle block diagram showing the block of FIG. 2 in a little circuit configuration. The schematic operation will be described with reference to FIG. The main switching elements S1 and S2 are alternately turned on and off at regular intervals under the control of the timing control means 6, but have a period in which they are turned off at the same time, as shown in (f) and (g) of FIG. .. At this time, the voltage VC1 at the intersection A of the two switching elements receives the positive and negative DC power supply voltages + VI and -VI and becomes an alternating current having a peak value VI as shown in FIG. At this time, the current iD1 or iD2 passes through the inductance L2 and the capacitor C2, is rectified by the diodes D1 and D2, is smoothed by the capacitors C3 and C4, and flows into the load RL. When the switching element S1 is on, the diode D1 is in the forward direction, so that the charge current iD1 shown in (a) of FIG. 4 flows through the capacitor C3. If the impedances of the switching element S1 and the diode D1 are sufficiently small and C3 >> C2 is set, the above current becomes a sinusoidal series resonance current due to the inductance L2 and the capacitor C2.

[0008] The resonance current does not flow any more because the diode D1 turns into a reverse voltage and turns off when the direction of the current is reversed after half a wave. In other words, this series resonance automatically stops when the resonance current has finished half-wave and returned to zero. At this time, the electric charge corresponding to the resonant current that has flown is accumulated in the capacitor C2, so that the voltage VC2 across both ends remains as shown in (e) of FIG. This charge does not cause energy loss because it is released to the load RL when the switching element S2 is next turned on. Further, since the energy stored in the inductance is proportional to the current, the energy of the inductance L2 when the resonance is stopped at the zero current is zero. Therefore, the generation of harmful current noise is extremely small.

When the switching element S1 is turned off, the current resonance has ended, so only the current iL1 ((d) in FIG. 4) flowing through the inductance L1 flows through the switching element S1. The value of the inductance L1 can be set independently of the inductance L2 for series resonance and the capacitor C2. Therefore, by setting L1 >> L2, the value of the current iL1 flowing through the inductance L1 becomes the series resonance current iD1. It can be small enough in comparison. Therefore, the switching element S1 can be turned off in the state of almost zero current.

On the other hand, the magnetic energy (current) stored in the inductance L1 while the switching element S1 is turned on becomes energy in which the inductance L1 and the capacitor C1 resonate in parallel. As a result, the voltage VC1 at the point A drops sinusoidally, and eventually exceeds zero and approaches -VI. This is the voltage resonance mode. When the potential at the point A becomes close to -VI, the diode D2 is turned on, and the energy (current) remaining in the inductance L1 is discharged to the capacitor C4 through L2, C2 and D2. However, since the current of the inductance L1 is set small, it does not change greatly in terms of current, and the potential at the point A maintains a value near -VI. Therefore, the zero voltage operation is possible in which the switching element S2 is turned on in the state where the voltage across the switching element S2 is very small, and the loss at the time of turning on is extremely small.

When the switching element S2 is turned on, the inductance L2 and the capacitor C2 cause a negative side current resonance, and the charge current iD2 shown in FIG. 4C flows into the capacitor C4 through the diode D2. After that, the above-described operation is repeated according to the switching elements S1 and S2 being turned on and off. In such a resonance type power supply device, since all switching operations of the switching elements are performed at zero voltage or zero current, the switching loss is small and the efficiency of the entire circuit is extremely high. In addition, since the series resonance current and parallel resonance voltage both have a spectrum close to a single frequency, the possibility of causing ringing or overshoot by interfering with the resonance dip in each part of the circuit is reduced, and unnecessary radiation such as harmonics is reduced. Is extremely small.

FIG. 5 is a practical circuit diagram in which the series resonance circuits L2 and C2 and the parallel resonance circuits L1 and C1 are configured using the self-inductance L1 and the leakage inductance L2 on the primary side of the transformer T1. The capacitor C1 (C2) is configured by connecting two capacitors C1 / 2 (C2 / 2) having a half capacity to each other in series. By doing so, L2 and C2 are included in the voltage resonance loop, but because of the relationship of L2 << L1, C2 >> C1, the existence of L2 and C2 actually affects the voltage resonance. Can be ignored. A full-wave rectification circuit 7 composed of four diodes is connected to the secondary side of the transformer T1, and the rectified output thereof is smoothed by the capacitor C3 and supplied to the load RL. The DC power source 1 may be a DC power source obtained by rectifying an AC power source, and in this case, it becomes an AC / DC converter.

The power supply device of FIG. 6 is of this type, and the full-wave rectifier circuit 8 consisting of four diodes full-wave rectifies the AC power supply AC and smoothes it with the capacitors C5 and C6. Therefore, here, the capacitors C5 and C6 serve as the DC power supply 1. The parallel resonant two-divided capacitor C1 / 2 is connected in parallel to the main switching elements S1 and S2. The capacitor C2 for series resonance is not divided but is connected in series to the primary winding of the transformer T1. The inductance L1 for parallel resonance is the self-inductance of the winding U3 of the transformer T1, and the inductance L2 for series resonance is the leakage inductance of the winding U3.

The timing control unit 6 includes two independent drive control circuits 61 and 62 so that the main switching elements S1 and S2 can be driven independently. The output stages of the drive control circuits 61 and 62 are drive elements Q1 and Q2, the on-timing of these elements Q1 and Q2 is controlled by CR time constant circuits 63 and 64, and the OFF timing is the switching element Q3 of the preceding stage. It is controlled by Q4 and CR time constant circuits 63 'and 64'. At this time, the AC components induced in the windings U1 and U2 of the transformer T1 are positively fed back to the constant circuits 63, 63 ', 64 and 64', respectively. The drive control circuits 61 and 62 have the same circuit configuration, but the drive elements Q1 and Q2 in the output stage are alternately turned on with a period of both being turned off, as shown in FIGS. .. That is, when the element S1 is on, the capacitor of the time constant circuit 63 'is charged by the current induced in the winding U1, and when the charge voltage rises to turn on the transistor Q3, the drive element Q1 is turned off. To do. When the element Q1 is turned off and the element S1 is turned off, the voltage applied to both ends of the primary winding is inverted by the induction of the primary winding of the transformer T1, and the time constant circuits 64 and 64 'start to be charged. Since the time constant of the circuit 64 'is larger than that of the circuit 64, the drive element Q2 is first turned on and the element S2 is turned on. After that, the capacitor of the time constant circuit 64 'is completely charged, the transistor Q4 is turned on, the element Q2 is turned off, and the element S2 is turned off. Next, the element S1 turns on, but the same operation is repeated thereafter. The details of this circuit operation are shown in Japanese Patent Publication No. 3-1914, which was filed and published by the present applicant except for the operation of the time constant circuits 63 and 64.

FIG. 7 shows the timing controller 6 in detail. The time constant circuit 63 of the drive control circuit 61 is composed of a resistor R11, a diode D11, a capacitor C12 and a drive element Q1 itself, and when the charging voltage of the capacitor C12 exceeds the base-emitter voltage of the drive element Q1. , The drive element Q1 is turned on. The charging time constant of the time constant circuit 63 is C12R11. The time constant circuit 63 'of the drive control circuit 61 is composed of a resistor R10, a capacitor C10, a diode D10 and a transistor Q3, and when the charging voltage of the capacitor C10 exceeds the base-emitter voltage of the transistor Q3, it rises. , The transistor Q3 is turned on and the drive element Q1 is turned off. The charging time constant of the time constant circuit 63 'is C10R10, which is set larger than that of C12R11 described above. These time constants define the oscillation frequency and duty ratio of the drive element Q1. The other drive control circuit 62 has the same configuration, the time constant circuit 64 is composed of a resistor R21, a diode D21, a capacitor C22 and a drive element Q2, and the time constant circuit 64 'is a resistor R20, a capacitor C20 and a diode. It consists of D20 and transistor Q4. The resistor R12, the capacitor C11, and the diode D11 of the drive control circuit 61 form an automatic start circuit. The same applies to the other drive control circuit 62, and the resistor R22, the capacitor C21, and the diode D21 form an automatic start circuit. This automatic start circuit turns on only one of the drive elements Q1 and Q2 when the power is turned on.

The timing control unit 6 is configured as described above, and includes main switching elements S1 and S2 driven by drive elements and their emitter stabilizing resistors R1 and R2, a parallel resonance capacitor C1, and a series resonance capacitor C1. The resonance capacitor C2, the resonance inductance U3, the feedback inductances U1, U2, etc. are arranged around the timing control unit 6. Generally, in order to miniaturize such a power supply circuit, it is conceivable to incorporate all the circuit components in a common HIC. However, if this is done, the inductance realized by a large capacity, high withstand voltage capacitor or coil will be reduced. Existence matters. When the circuit of FIG. 7 is put to practical use, the breakdown voltage and capacitance value of each capacitor are as shown in the table below.

[0017]

TABLE 1 Resistance to pressure capacity C12, C22 ~ number V 0.33μF C11, C21 ~6.3V 330μF C10 , C20 ~ number V 0.027μF C1 / 2 ~340V ~1800pF

The capacitor C1 / 2 shown in the above table has a small capacitance but a large withstand voltage, and is not suitable for HIC. The other capacitors have low withstand voltage, but all of them have large capacities and are not suitable for HIC. Therefore, in this invention, these capacitors and inductance parts are externally attached, and the other parts are made into a HIC to achieve miniaturization.

FIG. 1 shows the same circuit as that of FIG. 7 modified into an arrangement suitable for HIC implementation, and the inside of a broken line frame in the drawing is the HIC implementation unit 100. In this HIC unit 100, only resistors R1, R2, R10, R11, R12, R20, R21, R22 and diodes D10, D11, D20, D21 and transistors Q1 to Q4, S1, S2 are integrated, and capacitors C1, C2, C10, C11, C12, C20, C21, C22 and inductances U1 to U3 are externally attached. By doing so, the HIC unit 100 that does not include the capacitor and the inductance can be sufficiently miniaturized, and the common HIC unit 100 can be used by setting the constants of the externally attached capacitor and inductance arbitrarily. Then, various power supply circuits can be configured.

[0020]

[Effect of the device]

 As described above, according to the present invention, in the resonance type power supply circuit for operating the switching element, the resonance capacitor and the inductance and the switching frequency setting capacitor are externally attached, and the remaining part has the HIC configuration. It is possible to realize the miniaturization of the entire power supply circuit by using the HIC and generalization by arbitrarily setting the external component constants.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an essential part showing an embodiment of the present invention.

FIG. 2 is a principle configuration diagram of a resonance type power supply device.

FIG. 3 is a detailed circuit diagram showing a specific example of the circuit of FIG.

4 is an operation waveform diagram of the circuit of FIG.

5 is a circuit diagram showing a modified example of the circuit of FIG.

FIG. 6 is a detailed circuit diagram of a practical resonance type power supply device.

7 is a detailed configuration diagram of a main part of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... DC power supply, 2 ... Switching means, 3 ... DC output means, 4 ... Series resonance circuit, 5 ... Parallel resonance circuit, 6 ... Timing control means, 6A ... HIC part, 6B ... External part, Q
1, Q2 ... Drive element, S1, S2 ... Main switching element, C1 ... Parallel resonance capacitor, C2 ... Series resonance capacitor, C10, C11, C12, C20, C2
1, C22 ... Capacitors for setting drive stage switching frequency, U1 to U3 ... Inductance.

Claims (1)

[Scope of utility model registration request] 1. A switching device comprising a series resonant circuit and a parallel resonant circuit, a switching unit having a switching element for switching a current flowing through these resonant circuits, and a timing control unit for controlling an operation timing of the switching element. In a resonance-type power supply circuit that causes series resonance with respect to a current during an ON period of an element and causes parallel resonance with respect to a voltage during an OFF period of the switching element, A power supply circuit characterized in that a resonance capacitor and an inductance and a switching frequency setting capacitor of the timing control unit are externally attached, and the remaining part is of a hybrid integrated circuit configuration.