JPS6118318A - Power source circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply circuit, and more particularly to a power supply circuit that can be used for AC input voltage values having a wide variety of voltage values.

A conventional power supply circuit of this type is shown in FIG. In the figure, there is an AC input source 1 having two voltage values, for example 115V and 230V, and this AC input is supplied via a power switch 2 to a subsequent rectification and smoothing circuit. As shown in the figure, this rectifying and smoothing circuit includes a rectifier 3, smoothing capacitors CI and C2 connected in series, a switching transistor Q1, and a high frequency transformer T1. A switch 4 is provided, and by switching this switch 4, it can be used in response to AC inputs of 115V and 230V, respectively.

In this configuration, since the switch 4 is a manual switch, accidents may occur due to forgetting to switch the switch, and there are problems in managing the power supply circuit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power supply circuit that automatically selects a subsequent circuit corresponding to the input voltage value without requiring any manual operation in response to input of a plurality of AC voltage values. It is to provide.

Structure of the Invention A power supply circuit according to the present invention is a power supply circuit that supplies an input voltage to a subsequent stage circuit corresponding to each of a plurality of input voltage values, and detects this input voltage value and generates a control signal according to this value. and a selection means for selectively selecting a subsequent circuit according to the control signal, and supplying an input voltage corresponding to the subsequent circuit selected by the selection means. do.

Example The present invention will be described in detail below using the drawings.

FIG. 2 is a circuit diagram of an embodiment of the present invention, and parts equivalent to those in FIG. 1 are designated by the same reference numerals. Another switch 6 is provided between the power switch 2 and the rectifier 3, and the on/off of this switch 6 is controlled by the input 1 that passes through the power switch 2.
This is done by the control signal 51 of the voltage detector 5 which detects the voltage value of . Further, the switch 4 that switches the subsequent stage circuit is controlled by another control signal 52 of the detector 5, and this control signal 52 is a signal corresponding to the voltage value of the applied input 1, and this control signal 52 is a signal corresponding to the voltage value of the applied input 1. Signal 52. A control signal 51 is generated after a predetermined time delay after the occurrence of , and the switch 6 is turned on.

With this configuration, the switching control signal 52 for the switch 4 is generated from the detector 5 in accordance with the voltage control signal value of the input 1, so that the subsequent rectifying and smoothing circuit corresponding to this voltage value is selected. After that, the control signal 51 is generated, so that the input voltage is supplied to the rectifying and smoothing circuit only after the switch 6 is turned on.

FIG. 3 is a circuit diagram of an embodiment of the present invention, and FIG.
Parts equivalent to those in the figures are indicated by the same reference numerals. This example is
The subsequent circuit is a rectifier 3, a tapped transformer T2,
This is an example including a switch 7 for selecting the tap of this transformer. The switch 7 is controlled by a control signal 52 from the detector 5.

In this example as well, the switch 7 is controlled in accordance with the value of the input 1 to select the tap of the transformer T2, and then the switch 6 is turned on and power is supplied.

According to the present invention, a subsequent circuit corresponding to an input voltage having various voltage values is automatically and appropriately selected.
This has the advantage that manual circuit switching is not required.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional power supply circuit, and FIGS. 2 and 3 are circuit diagrams of embodiments of the present invention. Explanation of symbols of main parts 1... Input source 2.6... Power switch 4.7... Selection switch 5... Voltage detector

Claims (1)

[Claims] A power supply circuit supplies an input voltage to a downstream circuit corresponding to each of a plurality of input voltage values, the power supply circuit comprising: means for detecting the input voltage value and generating a control signal according to the value; 1. A power supply circuit comprising: selection means for selectively selecting the latter circuit; and supplying the input voltage corresponding to the latter circuit selected by the selection means.