JPS6032567A - Power source - Google Patents

Abstract

PURPOSE:To simplify a circuit configuration by operating a switching element ON by discharging energy stored in an inductor when a switching unit is ON, at OFF time. CONSTITUTION:Energy is stored in the primary winding 71 of a transformer 7a when a transistor 12 is ON, the energy is discharged through an energy discharging circuit D having a diode 13, a capacitor 14 and a resistor 15 when the transistor 12 is OFF. This current is flowed from the gate of a thyristor 5 to a cathode and to the primary winding 71 of the transformer 7a. Then, the transformer 7a is returned to the initial state, and a thyristor 5 is turned ON by the discharged energy. This performs a role of a rectifying and smoothing circuit by the energy discharging circuit, thereby simplifying as an inductor the transformer and the circuit configuration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply device having a smoothing capacitor for smoothing a rectified voltage on the input side. (!+) So-called capacitor input type rectifier and smoothing circuits, which smooth the rectified voltage with a capacitor, are often used.This capacitor requires a large capacity such as t, which is a device with a large output. What about a large capacitor?
The rush current when connecting to a commercial power source also increases.

This rush current can cause the overcurrent breaker to malfunction or have a negative effect on the fuses that protect the input circuit, the diodes that make up the rectifier circuit, the smoothing capacitors, etc. It has been proposed to connect a current limiting resistor in series with a smoothing capacitor.In other words, the one shown in Figure 7 (&) connects a resistor between the output terminals of a rectifier bridge (hereinafter referred to as a rectifier circuit). The inrush current is alleviated by connecting the capacitor 3 in series.However, in this case, the charging current of the capacitor 3 always flows through the resistor, so there is a power loss here. Generates heat.

Furthermore, as shown in Fig. 1(b), a thermistor 6 is provided in place of the resistor 6, and the inrush current and power loss are kept low by utilizing the temperature-dependent resistance change characteristics of the thermistor 6. This was also insufficient for reducing the W force loss.

To deal with this, connect a switching device in parallel to the resistor 3 as shown in Figure 1(c), connect it to a commercial power source, and then turn on this switch t when the capacitor 3 is charged to a certain extent, or As shown in FIG. 1(d), a thyristor S is connected in parallel to the resistor U, and a capacitor 3 is similarly connected.
It is conceivable that the thyristor S is turned off when the thyristor S is charged to a certain extent. FIG. 2 shows a specific configuration of a power supply device using this thyristor.

This power supply device is a so-called forward converter type switching regulator.

Here, the transformer 7 has a primary winding 78, a secondary winding 72 and a tertiary winding 73, -th order @N) 7/ is a control circuit l/
The transistor /, which is controlled on and off by 9 are connected to each other. That is,
The tertiary winding 73 and the rectifying and smoothing circuit 9 are connected to the thyristor S.
constitutes a signal source.

Further, an energy release circuit formed by connecting in series a diode 13/3 and a parallel circuit of a capacitor /9 and a resistor /j- is connected in parallel to the negative winding 7/. In this energy release circuit, the energy stored in the primary winding 7/ when the transistor /2 is turned on is transferred to the transistor /2.
This is provided in order to prevent damage to the transistor/tension caused by applying voltage to the transistor 7.2 when the transistor 7.2 is turned off.

The left anode of the thyristor is connected to the junction between the positive terminal of the rectifier circuit and the resistor, and the cathode of the thyristor S is connected to the junction of the resistor and capacitor 3. It is connected to the positive terminal of the rectifying and smoothing circuit 9.

In Figure 1, when capacitor 3 is charged through resistor 1 and transistor 12 is turned on by control circuit l/, the voltage across capacitor 3 changes to transistor/transistor 12.
2 to the primary winding 71 of the transformer.

On the other hand, when the transistor/U is turned on, a voltage is also induced in the tertiary winding 73 of the transistor, and this voltage is converted into a DC voltage by the rectifier/smoothing circuit 9, and the thyristor S
The capacitance of P is applied between the gates. Therefore, gate to 5 thyristor S? A current is supplied to turn off the capacitor 3, after which the capacitor 3 is charged through the thyristor S.

In this way, when connected to a commercial power source, the inrush current is alleviated by the resistor, while the thyristor 3 suppresses power loss and associated heat generation while power is being supplied to the load 10. be able to.

Here, the control circuit // is, for example, 20-10[:
KH2], and transistor/2 repeatedly turns on and off in response to this frequency.

However, in the conventional power supply device shown in FIG. 2, in order to turn on the thyristor 3, a transformer 7 having a tertiary winding 73 is used to constitute a signal source for the thyristor as described above. Moreover, since the rectifying and smoothing circuit 9 is required, the circuit configuration becomes complicated and costs are increased.

The present invention has been made to eliminate the above-mentioned drawbacks.
The purpose of the present invention is to provide a power supply device that can significantly simplify the circuit configuration and thereby significantly reduce costs.

To achieve this object, the present invention provides a power supply device that turns on and off the voltage of a smoothing capacitor charged through a current limiting resistive element using a switch notching device and supplies it to a load device including an inductor. , an energy release circuit that releases the energy stored in the inductor when the switching device is turned on and when the switching device is turned off; and a switching device that is connected in parallel to the resistive element and can be turned on by the energy released by the energy release circuit. The device is characterized by being equipped with an element.

An embodiment of the present invention will be described below with reference to FIG.

FIG. 3 is a water circuit diagram of a configuration example applied to a forward converter type switching regulator similar to that in FIG. 1, and the same reference numerals as in FIG. 2 indicate the same elements. Therefore, in FIG. 1, a transformer 7 having a tertiary winding 73 is used, and a rectifying and smoothing circuit 9 is connected to this tertiary winding 73.
The rectifying and smoothing circuit 9 is removed and a transformer 7a is used as an inductor without a tertiary winding. Then, the transformer 7a, the rectifying and smoothing circuit g, and the load 10 are connected to the load device faL.
It consists of In addition, in Fig. 2, an energy release circuit consisting of a diode 13, a capacitor /l, and a resistor /S was connected in parallel to the primary winding of the transformer, but here, one end of the energy release circuit is connected in parallel to the primary winding of the transformer. Similarly, it is connected to the junction between the transistor 7.2 as a switching device and the primary winding 71, and the other end is connected to the gate of the SIRISK S as a switching element.

The operation of the power supply device configured as described above will be explained below, focusing mainly on the parts that are different in configuration from FIG. 2.

First, when the transistor 7.2 is turned on, energy is stored in the primary winding 7/ of the transformer 7a, and then when the transistor saw is turned off, this energy is transferred to the diode-rl,
3. Energy is released through an energy release circuit consisting of a capacitor/+ and a resistor/S. This current is thyristor S
flows from the gate to the cathode and into the primary winding of the transformer 7a. Thus, the transformer 7a returns to its initial state, and the thyristor S is turned on by the emitted energy.

This means that the energy release circuit plays the role of the rectifier and smoothing circuit 9 as the sirisk drive circuit shown in Figure 2, and the circuit configuration is significantly simplified along with the simplification of the transformer as an inductor. Ru.

Next, Figure 2 is a circuit diagram showing the configuration of another embodiment of the power supply device according to the present invention, which is applied to a so-called step-up type Suizotinda regulator.

Note that the same parts as in FIG. 3 are given the same reference numerals.

Here, the load device L' includes a choke coil 20 as an inductor, a capacitor and a load connected to the diode)'.
23, and the configuration of the switching regulator itself with the load device L' is well known, for example, 1.20 CKH]
~so [KH2:] It will work.

The energy release circuit D' consists of a series circuit of a diode 30 and a current-limiting resistor 3, and the anode F of the diode 30 is connected to the non-power supply side terminal of the choke coil J. Connected to the gate of thyristor S.

In FIG. 9, after the smoothing capacitor 3 has been charged to some extent through the resistor 2, when the transistor 2 is turned on, energy is stored in the choke coil J.

Subsequently, when TRAN and RISK/J are turned off, part of the energy of the choke coil 20 is transferred to the energy release circuit D'.
and turns on the thyristor S.

Therefore, from then on, the smoothing capacitor 3 is charged via the thyristor S while the transistor 12 is operating in a predetermined manner. However, the same effect as described above can be achieved even when another resistive element such as a single mister is used instead.

In addition, in the above embodiment, the case where the resistance is connected in parallel with the resistance is explained, but instead of this resistance,
Other switching elements, such as transistors, may be used as long as they can be turned on by the energy released by the energy release circuit.

As is clear from the above description, according to the power supply device of the present invention, the circuit configuration for alleviating rush current and reducing power loss is significantly simplified.

At the same time, excellent effects such as significant cost reduction can be obtained.

[Brief explanation of the drawing]

Figure 1 (al to (dl) is a wiring diagram showing the configuration of the main parts of a conventional power supply device, Figure 2 is a wiring diagram showing the configuration of a conventional power supply device, and Figure 3 is a wiring diagram showing the configuration of a conventional power supply device. Figure 1 is a wiring diagram showing the configuration of an embodiment, and Figure 1 is a wiring diagram showing the configuration of another embodiment. , S... Thyristor as a switching element, Ria... Transformer as an inductor,
/J...Transistor as a switching device, L
, L'...load device, D, D'...energy release circuit. Applicant's agent Kiyohiro Inomata 1 Figure (01(b) fc) (d) B 2 Figure 3 Box 4 Figure

Claims (2)

[Claims] (1) In a power supply device that supplies a voltage of a smoothing capacitor charged via a current limiting resistive element to a load device including an inductor by turning it on and off using a switching device, when the switching device is turned on, the voltage of a smoothing capacitor is turned on and off and supplied to the inductor. The device is characterized by comprising an energy release circuit that releases stored energy when the switching device is turned off, and a switching element that is connected in parallel to the resistance element and can be turned on by the energy released by the energy release circuit. power supply. (2) The power supply device according to claim 1, wherein the switching element is a thyristor, and the thyristor is turned off by a current flowing through the energy emitting circuit.