JPH05260659A - Automatic power supply switching circuit - Google Patents

Abstract

PURPOSE: To output a voltage of 220V constantly by detecting the voltage of a commercial power supply to be supplied to a system and switching a voltage doubler rectifier means between a half-wave rectification circuit and a full-wave rectification voltage doubler circuit based on the detected voltage. CONSTITUTION: When an AC 220V commercial power supply voltage is applied to an automatic power supply switching circuit, a low level signal is outputted from an output photo-PS because the output voltage from a voltage division means 20 being supplied to the A/D input photo-A/D of a system controller 30 is higher than a reference voltage. When the low level signal is fed to the base of a transistor TR in a voltage doubler selector means 40, the transistor TR is turned off and the movable contact terminal COM of a relay RY is coupled with a contact terminal NC and thereby a voltage doubler rectifier means 10 serves as a half-wave rectification voltage doubler circuit. When an AC 110V is applied to the automatic power supply switching circuit, a high level signal is outputted from the output photo-PS and the terminal. COM is coupled with a terminal NO and thereby the rectifier means 10 serves as a full-wave rectification voltage doubler circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power source automatic switching circuit, and more particularly to a power source automatic switching circuit which automatically switches between two types of commercial power source voltages according to the system working voltage and always outputs a voltage of 220V. ..

[0002]

2. Description of the Related Art Generally, a power supply switching circuit for switching two kinds of commercial power supplies to a working voltage of a system is shown in FIG.
The power supply switching circuit shown in FIG.
As described in No. 15, this smoothing capacitor C
1, C2, a plurality of diodes D1 to D4, and a thyristor S1. Half-wave rectification is performed when the voltage of the commercial power source is 220V, and full-wave rectification is performed when the voltage is 110V. The operating voltage of the system is switched.

[0003]

As described above, in the conventional circuit for switching to the working voltage of the system, the control means for accurately controlling the operation of the thyristor for selecting the half-wave and full-wave rectification by the commercial power supply voltage is provided. For example, when the commercial power supply voltage is 220 V and full-wave rectification is performed and the system power is supplied to the system, the component elements in the system are broken.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention has been devised to solve the above-mentioned various problems, and an object of the present invention is to half-wave the commercial power supply voltage by the voltage of the commercial power supply supplied to the system. Another object of the present invention is to provide an automatic power supply switching circuit that constantly outputs a voltage of 220V by performing full-wave rectification and automatically switching to a working voltage of the system.

[0005]

In order to achieve the above object, an automatic power supply switching circuit according to the present invention is a voltage doubler rectifier for rectifying a commercial power supply supplied to a system by half-wave and double-wave. A voltage dividing means for dividing the commercial power supply voltage half-wave rectified and doubled by the voltage doubling rectification means, and whether the commercial power supplied to the system upon receiving the voltage divided by the voltage division means is 110V. 2
The system controller includes a system controller that determines whether the voltage is 20V and outputs data corresponding to the voltage, and a voltage doubler selecting unit that selects the operation of the voltage doubler rectifying unit based on the data output from the system controller. Characterize.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 2 and 3, the voltage doubler rectifying means 10 is
Rectifier diodes D1 and D2 are connected in parallel to one side input terminal in opposite directions to each other, and diodes D1 and D2 are connected in parallel.
Although the smoothing capacitors C1 and C2 are connected between both terminals of the junction, the commercial power source is rectified into half-wave and full-wave by the operation of the relay R5 to output a doubled voltage.

The voltage dividing means 20 is electrically connected to the output terminal of the voltage doubler rectifying means 10 so as to convert the commercial power source, which has been half-wave rectified and doubled by the voltage doubler rectifying means 10, into a voltage which can be sensed by a system controller described later. Connected to the capacitor C3 for smoothing the output voltage, and a resistor R2 for dividing the output voltage of the voltage doubler rectifying means 10 through the capacitor C3.
R3, ruffle removal capacitor C4 and diode D
3, D4. The diodes D3 and D4 are provided so that a stable voltage is supplied to the system controller 30.

After the system controller 30 converts the analog signal output from the voltage dividing means 20 into a digital signal, 110 V is selected and compared with the stored reference data, is the commercial power supplied to the system 110 V? Then, it is determined whether or not it is 220V, and the control signal corresponding to it is output.

The voltage doubler selecting means 40 is a switching transistor TR which is operated by a control signal output from the system controller 30, and the voltage doubler rectifying means 10 is a half-wave or full-wave commercial voltage when the switching TR operates. Relay R selected to rectify and output double voltage
It is composed of Y and Y.

The operation of the automatic power supply switching circuit according to the present invention having the above structure will be described in detail below. When a commercial power supply of 220 V is supplied to the automatic power switching circuit shown in FIGS. 2 and 3, the diode D of the half-wave rectification type voltage doubler circuit of the voltage doubler detection means 10 is supplied.
1 and half-wave rectified through the capacitor C1 and supplied to the voltage dividing means 20. The output voltage of the voltage doubler detecting means 10 supplied to the voltage dividing means 20 is the resistances R1 and R2.
A / D of system controller 30 after divided by
It is input to the input photo A / D. At this time, the system controller 30, which receives the voltage output from the voltage dividing means 20, compares the data corresponding to the above voltage with the set reference data.

The reference data preset in the controller 30 is voltage dividing means 20 when the commercial power source is 110V.
This is the data obtained by digitizing the voltage output from the.

Therefore, the power source automatic switching circuit is 220V AC.
When commercial power is applied, the system controller 30
Voltage dividing means 20 supplied to the A / D input photo A / D of
Since the data corresponding to the output voltage is larger than the set reference data, the main photo PS of the system controller 30 outputs a low level signal.

It is output from the output photo PS of the controller 30. When the low-level signal is supplied to the switching transistor TR of the voltage doubler selecting means 40, the switching transistor TR is turned off, and thus the relay RY.
The movable contact terminal COM of is connected to the contact terminal NC in the initial state. In this way, relay RY
When the movable contact terminal COM of is connected to the contact terminal NC, the voltage doubler rectifying means 10 becomes a half-wave rectifier voltage doubler circuit and supplies an effective value of AC 220V, that is, a voltage of √2 × 220V to the system.

On the other hand, when AC110V commercial power is supplied to the automatic power switching circuit, the output voltage of the voltage dividing means 20 supplied to the A / D input photo A / D of the system controller 30 is the set reference voltage. Therefore, a high level signal is output at the output photo PS of the system controller 30.

When a high level signal is output from the output photo PS and supplied to the base terminal of the switching transistor TR of the voltage doubler selecting means 40, the switching transistor TR is turned on, and a current flows through the relay coil. The contact terminal COM moves to the contact terminal NO on the other side.

Therefore, the voltage doubler rectifying means 10 becomes a double wave rectifier type voltage doubler circuit and supplies a system × √2 × 110 V voltage.

[0017]

According to the present invention which operates as described above, the voltage of the commercial power supply supplied to the system is detected, and the voltage doubler rectifying means is automatically switched by the half-wave rectification or double-wave rectification type voltage doubler circuit. Therefore, when the commercial power supplied to the above system is 110V or 220V, it is always 220V.
Since the output voltage is output, it has an advantage that the circuit elements of the system can be prevented from being destroyed.

[Brief description of drawings]

FIG. 1 is a conventional power supply switching circuit diagram.

FIG. 2 is a block diagram of the present invention.

FIG. 3 is a detailed circuit diagram of the present invention.

[Explanation of symbols]

 10 double voltage rectifying means 20 voltage dividing means 30 system controller 40 double voltage selecting means

Claims (2)

[Claims] 1. A voltage doubler rectifying means for rectifying a commercial power supply supplied to a system into half-wave and double-wave and outputting a voltage doubler, and a commercial power supply voltage half-wave rectified by the voltage doubler rectifier. The voltage dividing means and the commercial power supply which receives the voltage divided by the voltage dividing means and is supplied to the system are 110.
It is judged whether it is V or 220V if
An automatic power supply switching circuit comprising a system controller that outputs data corresponding to this and a voltage doubler selecting unit that selects an operation of the voltage doubler rectifying unit based on the data output from the system controller. 2. The system voltage controller of the system controller, wherein the voltage doubler selecting means compares the data corresponding to the voltage output from the voltage dividing means with the set reference data, and outputs a control signal corresponding to the resultant value. It is composed of a switching transistor operated by an output control signal, and a relay that determines by operation of the switching transistor that the voltage doubler rectifier unit rectifies a commercial power supply into half-wave and full-wave to output a voltage doubler. The automatic power supply circuit according to claim 1, wherein: