JPS59162774A - Switching method of ac input voltage - Google Patents

Abstract

PURPOSE:To be readied to cope with 100V or 200V power sources by composing to automatically select a double voltage full-wave rectification and a bridge rectification. CONSTITUTION:A 4-pole connector 4 is provided between a wiring plug-in connector 3a and a rectifier having diodes D1-D4. They are connected by the connector 4 so that a double voltage rectification is automatically connected in case of 100V in response to 100V of the commercial AC input side and a bridge rectification is automatically connected in case of 200V in response to 200V of the commercial AC input side. The rectified input is supplied to a load 2 through a DC constant-voltage device 1 by a switching regulator.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an improvement in an alternating current input voltage switching method for electrical equipment.

(b) Background of the Technology In recent years, DC constant voltage power supplies based on a switching regulator system have been widely used as power supply means for electrical equipment, particularly electronic circuits using semiconductor elements.

A constant voltage DC power supply using a switching regulator usually converts a commercial alternating current by direct single-wave or full-wave rectification, smoothes the pulsating current, and converts it into direct current, which is then operated as an input power source.

In order to prevent the inflow of alternating current potential that occurs when electrical equipment is operated in parallel, the primary and secondary sides of the winding of the main transformer in the switching regulator circuit are insulated and separated.

(c) Conventional technology and problems Block diagram of the current voltage switching method in a DC constant voltage power supply using the conventional switching regulator system 'f
c Shown in Figure 1. In the figure, 1 is a DC constant voltage circuit using a switching regulator, 2 is a load, I)+, Dw+
Ds+ D is a diode, CItCl is a capacitor, and SW is AC input 100pol) (V) 7200 V
The AC power supply for small electrical equipment in Japan usually has a single-phase 100mm
(2) At times, a predetermined DC voltage of 2 oovv is obtained by voltage doubler full-wave rectification, and at single-phase 200 V, by bridge rectification, and is used as an input means to the constant voltage circuit 1.

Normally, this SW is installed inside the device and is preset when the device is delivered.The power supply connection means added for commercial AC input is a JIS C8303 plug-in connector for wiring.
It is prepared in accordance with the regulations, so if the operator accidentally
V / 200 V input will not be confused, but
For example, when the user relocates the electrical equipment and changes the current commercial AC input, there are cases where the SW is set incorrectly and the constant voltage circuit 1 etc. is damaged. SW
is set to the 200V side, and the AC input is 100V.
is applied, the series connected capacitor C+
, Ct, that is, the input of the constant voltage circuit 1, is 1/
Since only 2 is applied, the specified output voltage cannot be obtained from the output of the constant voltage circuit 1, and the load 2 malfunctions. However, in this case, the load 2 is normally configured to send out an error detection signal, or, although not shown, the pressure circuit 1 is configured to send out a low voltage detection signal to report an abnormality and stop the operation of the load. Therefore, there is no possibility of complete damage to the constant voltage circuit 1 or the load 2.

On the other hand, set the SW to 100V side and use 200V as AC input.
Similarly, when V is applied, the constant voltage circuit 1 reaches twice the DC input voltage, for example, 400 VK, and for example, the switching element may be damaged in a short period of time due to insufficient side pressure. Of course, when an overvoltage occurs in its output, the constant voltage circuit 1 is equipped with an overvoltage detection function and sends out the detection signal, and also stops the foot voltage control function to protect the load 2. In some cases, damage may extend to load 2. Further, in order to prevent this, the constant voltage circuit 1 can be provided with a function of adapting to a wide range of DC input voltages, but this has the drawback of increasing costs.

(d) Purpose of the Invention The purpose of the present invention is to prevent damage to the DC constant voltage power supply due to the above-mentioned SW switching error, and to apply a rectification system compatible with 100 V or 200 V to the commercial AC input without setting by switching the SW. The aim is to provide a means for automatically selecting a connector depending on the connector to which it is connected.

(e) Structure of the Invention The object of the invention is to provide a means for rectifying an AC input single-phase 200 pol If input to a bridge-connected diode, and a means for smoothing the output from the rectifying means with a series-connected capacitor. Means for double-voltage full-wave rectification by applying single-phase 100-volt AC input to the intermediate connection point of the series-connected capacitors, and means for selectively connecting a different input for each 100-volt or 200-volt AC input to the bridge-connected diode. AC input voltage, characterized in that the connecting means inputs an AC input of 100pol)t or 200pol)f, selects the corresponding rectifying means, and obtains a constant voltage across the series-connected capacitors. This is achieved by providing a switching method for

(f) Embodiment of the Invention An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 2(a) and 2(b) are block diagrams of a method for switching an AC voltage of a DC constant voltage power supply using a switching regulator system according to an embodiment of the present invention. However, Fig. 2(a)
It is assumed that the connection means is provided when the commercial input power supply voltage is 100V, and when the voltage is 200V in FIG. 2(b). In the figure, 1 is a DC constant voltage device using a switching regulator, 2 is a load, 3a and 3b are wiring plug connectors, and 4 is 4
Pole connector, D, D2. , D3°D4 are diodes and ClIC2 is a capacitor. Components in the figures having the same reference numerals as those of the conventional apparatus have characteristics and functions common to the conventional apparatus.

The wiring plug connector 3a is for 100V specified by JIS C8303, and the connector 3b is for 200V according to JIS C8303. In this way, the configuration from the 4-pole connector 4 to the load is the same as the conventional one, but if you select the commercial AC input side from the 4-pole connector 4 corresponding to 100 V or 200 V, it will automatically convert to 100 V. When the voltage is 200V, the voltage doubler full-wave rectification is selected, and when the voltage is 200V, the bridge rectification is selected, so the capacitor C connected in series is selected.
A constant voltage is obtained across 5 and C2, 100V and 2
Even if 00V is mixed, an incorrect DC voltage may be applied to the constant voltage circuit 1.
is never applied.

(g) As described in the detailed description of the invention, according to the present invention, one of the
The present invention is useful because it provides a method for switching AC input voltages in which switching connections are automatically selected for 00V and 200V, thereby preventing accidental damage to electrical equipment.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional AC input voltage switching method, and FIGS. 2(a) and 2(b) are block diagrams of an AC input voltage switching method in an embodiment of the present invention. In the figure, 1 is a constant voltage circuit, 2 is a load, and 3a. 3bFi wiring plug connector, 4 is 4-pole connector, ■). ~4 is a diode, CI+2 is a capacitor, and SW is a lock switch.

Claims (1)

[Claims] AC input single phase 200pol to bridge connected diode)
Means for inputting f and rectifying it, means for smoothing the output from the rectifying means using a series-connected capacitor, and inputting an AC input single-phase 100 pol If to the intermediate connection point between one input of the bridge connection and the series-connected capacitor. Means for full-wave rectification of the voltage doubler and AC input 10 to the bridge-connected diode
Must be provided with means for selectively connecting different inputs for each 0 volt or 200 volts, and the connecting means may be used to select one of the AC inputs.
AC input voltage switching method 0 characterized by inputting 00 volts or 200 pol If, selecting the corresponding rectifying means, and obtaining a constant voltage across a series-connected capacitor.