JPH0283715A - Power unit - Google Patents

Abstract

PURPOSE:To evade the working stop state of a stabilizing circuit which acquires the stabilized DC voltage of another kind by acquiring the stabilized DC voltage taken out as the switching regulator output via a switch means. CONSTITUTION:A switching regulator 101 outputs the stabilized DC voltage from an input AC power supply. A stabilizing circuit 103 stabilizes the DC voltage of another kind that is taken out of the regulator 101 and has the same polarity as the stabilized DC voltage. In such a constitution of a power unit, a switch means 105 connects the output terminal of the circuit 103 to the output terminal of the regulator 101 when the operation of the circuit 103 is stopped. Thus the output terminal voltage of the circuit 103 is raised in the positive direction against 0V via the means 105 even in case the output terminal voltage is drawn in the negative direction against 0V and the operation of the circuit 103 is stopped.

Description

[Detailed Description of the Invention] [Summary] Regarding a power supply device that can stably supply each of a plurality of DC voltages, it is possible to avoid the operation stoppage of the stabilizing circuit used for stabilizing the DC voltage, A switching regulator that outputs a stabilized DC voltage from an input AC power supply with the aim of stably supplying each voltage, and another DC voltage that is taken out from this switching regulator and has the same polarity as the stabilized DC voltage. In a power supply device that outputs at least two stabilized DC voltages, the power supply device is equipped with a stabilizing circuit that stabilizes the voltage, and a switch means that connects the output terminal of the stabilizing circuit to the output terminal of the switching regulator when the stabilizing circuit stops operating. Prepare and configure.

[Industrial application field]

The present invention relates to a power supply device that can stably supply each of a plurality of DC voltages.

[Conventional technology]

For example, 1. AC commercial power (100 to 230 V, 5
In order to prevent malfunctions due to fluctuations in power supply voltage and frequency, electronic equipment that receives power (0 to 60Hz) and is supplied as an operating power supply uses a power supply device (regulated power supply) that always supplies power at a constant voltage and constant frequency. ) is used.

Stabilized DC power supplies used in such electronic equipment (computer), etc., use a series regulator, which connects a variable resistor (using class A transistor operation) in series between the DC output and the load. ), a method that detects fluctuations in DC output voltage and controls the amount of current (input current) (
switching regulator), but the latter method is widely used as a method that can obtain high conversion efficiency without consuming power.

On the other hand, the DC voltage used in such electronic equipment is T
-1-5VXMO3-LS I and analog circuits require +12■ (~±15V) for TI- circuit,
Since it is uneconomical to install each power supply device separately, a power supply device that can take out each DC voltage at the same time is often used.

FIG. 4 is a circuit configuration diagram showing an example of a conventional power supply device that can obtain a plurality of DC voltages.

In the figure, an AC input is rectified and smoothed by a diode-I hybridization circuit 401 composed of diodes D1 to D4 and a capacitor 403, and then supplied to a transformer 405.
From the secondary side of the transformer 405, a rectifier circuit 411.4+,
2, -i-5V through smoothing circuit, 1113.414
It is configured to take out two DC voltages, ``12'' and ``12''.

Here, assuming that +5 V DC voltage is the main output, the switching regulator configuration consisting of the control circuit 421 and the transistor 423 detects fluctuations in the DC output voltage and changes the on/off ratio of the transistor 423, and the I.
The magnitude of the current (input current) on the primary side of the lance +05 is controlled to obtain a stable DC voltage -t5v.

On the other hand, the suboutput power of DC voltage i-+2V is smaller than the main output power, and the stabilizing circuit 431 stabilizes the unstable output obtained by providing the subwinding on the I lance 405 ( series regulator).

[Problem to be solved by the invention]

By the way, electronic devices to which such a stabilized DC voltage is supplied include loads (ICs, transistor circuits, (Other operational amplifiers, etc.) exist.

FIG. 5 shows such electric power 7. It is a figure explaining fl of equipment and the state of cargo.

In the figure, the power supply device as shown in Fig. 4 is connected from 4°O to +
-5V, 112■ stabilized DC voltage is supplied, separately -
A 12V DC voltage is supplied to the load A321.
The configuration is such that μm2V and 0■ are connected to the load B523, and ]12■ and 12V are connected to the load C525.

In such a configuration, there is no problem if the voltage ±12V applied to the load C525 rises (or falls) at the same time, but if, for example, -12V rises first and falls to L, then One terminal of the load C525, on which the DC voltage of +12■ is supposed to rise, is first pulled in the negative direction from O■.

At this time, power supply device 4 that obtains a stabilized DC voltage of 112■
000 stabilizing circuit 431, from the voltage (2) of the terminal a on the -FI22 side (the voltage (2) of the terminal A on the lV side).

becomes high (V, <Vb), and the temperature rises, +-1,
The DC voltage of 2■ sometimes stopped rising forever.

The present invention solves the problems of the prior art as described in 2. In a configuration in which a plurality of stabilized DC voltages can be obtained, the stabilizing circuit used for stabilizing the DC voltage stops operating. It is the object of the present invention to provide an electric current tA device that can avoid latch-up and stably supply each meandering voltage.

[Means to solve the problem] FIG. 1 is a block diagram of the principle of the present invention.

In the figure, a switching 1/regulator 101 outputs a stabilized DC voltage from an input AC power source.

A stabilizing circuit 103 is taken out from this switching regulator and stabilizes another DC voltage of the same polarity as the stabilized DC voltage.

In such a power supply device that outputs at least two stabilized DC voltages, the switch means 1.5 connects its output terminal to the output terminal of the switching regulator 101 when the stabilization circuit 103 stops operating.

[For production]

The present invention provides, for example, a power supply device that stabilizes and outputs a positive DC voltage by a switching regulator 101 and a stabilizing circuit 103, respectively.
Even if the output end voltage of the switch device 10 is pulled in a negative direction with respect to OV and the operation stops (latch-up), the switch means 10
5 in the positive direction with respect to 0■, it is possible to recover from latch-up.

Note that the switching means 105 can be easily realized by, for example, a diode, and in the above case, the stabilizing circuit 10
A diode whose cathode side is connected to the output terminal of No. 3 is connected.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a circuit configuration diagram showing an embodiment of the present invention.

Note that the embodiment circuit shown here has the same configuration as the conventional power supply device shown in FIG. 4, and the explanation of the configuration and operation of each part will be omitted by giving the same numbers.

The feature of the present invention is that in this embodiment, between the main output of DC voltage "-5" and the sub-output of DC voltage +12V, the anode is connected to the 4-5V side and the cathode is connected to the +12V side.
The configuration is such that a diode 205 connected to the side is inserted (forward connection during latch-up).

That is, as shown in Fig. 5, when one DC voltage rises (falls) first with respect to the load 525 connected between the DC voltage +12V and the other DC voltage -12V, In this case, the output terminal voltage of the stabilizing circuit 431 becomes a negative voltage. However, the main output DC voltage +5■ is supplied by the diode 205, and the output terminal voltage of the stabilizing circuit 431 is once raised to approximately +5■, so even if latch-up occurs in the negative direction, the stabilizing circuit 431
operation can be restored immediately.

Note that, as shown in Figure 3, the DC voltages of the main output and sub output are both negative (for example, -5■ and -12■).
In this case, the connection direction of the inserted diode 305 is reversed.

In addition, here, a switch means (FIG. 1, 1
Although a diode 205305 is shown as 05), a transistor with its base and emitter short-circuited may be used as a diode, and any element that operates in the same manner is not limited to a diode.

〔Effect of the invention〕

According to the present invention, the stabilized DC voltage taken out as the switching regulator output is used, and by adding a simple circuit such as a diode, the other stabilized DC voltage is obtained. circuit (
Series regulator) operation can be guaranteed,
It is extremely useful in practical terms.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of the present invention, Fig. 2 is a circuit configuration diagram showing one embodiment of the present invention, Fig. 3 is a diagram showing the main part configuration of another embodiment, and Fig. 4 is a diagram showing a plurality of DC FIG. 5 is a circuit configuration diagram showing an example of a conventional power supply device that can obtain voltage. FIG. 5 is a diagram illustrating the state of the load of electronic equipment on the power supply device. In the figure, 101 is a switching regulator, 103 is a stabilizing circuit, 105 is a switch means, and 205.305 is a diode. State box diagram of electronic equipment load for ζmi-distinct power supply device

Claims (1)

[Claims] (1) A switching regulator (101) that outputs a stabilized DC voltage from an input AC power source, and a stabilizing circuit that stabilizes another DC voltage that is taken out from this switching regulator and has the same polarity as the stabilized DC voltage. (
103) and outputs at least two stabilized DC voltages, the output terminal of the stabilizing circuit (103) is connected to the output terminal of the switching regulator (101) when the stabilizing circuit (103) stops operating. A power supply device comprising switch means (105).