KR0127531Y1 - Automatic transduced circuit for ac 110v/220v - Google Patents

Abstract

The present invention relates to an AC 110V / 220V automatic conversion circuit, and more particularly, to an AC 110V / 220V automatic conversion circuit intended to prevent malfunction and damage of a system caused by low and high voltages caused by user misuse. The object of the present invention is a line filter unit (1) for removing noise of an input AC voltage, an SMPS transformer (2) for converting an AC voltage output from the line filter unit (1) into a predetermined AC voltage, and the SMPS transformer ( Rectifying and smoothing the rectified and smoothed AC voltage output from 2) to make a predetermined DC voltage, and the DC voltage obtained from the rectified and smoothed part 3 are detected and the light emitting diode is driven with the resultant value. And voltage detection and display section 4 for displaying a voltage state externally.

Description

AC 110V / 220V Automatic Conversion Circuit

1 is a conventional AC 110V / 220V automatic conversion circuit diagram.

2 is an AC 110V / 220V automatic conversion circuit diagram of the present invention.

3 is a detailed circuit diagram of the voltage detection and display unit of FIG.

* Explanation of symbols for main parts of the drawings

1: Line filter part 2: SMPS transformer

3: rectification and smoothing unit 4: voltage detection and display unit

The present invention relates to an AC 110V / 220V automatic conversion circuit, and more particularly, to an AC 110V / 220V automatic conversion circuit to prevent a malfunction of a system and a system damage caused by a low voltage and a high voltage caused by a user's misuse.

In general, 110V / 220V automatic selection method by SMPS power supply is automatically switched by using IC, and in linear power supply (hereinafter referred to as LPS) method, user selects 110V / 220V by using selection switch. It is.

In the LPS method, a conventional AC 110V / 220V automatic conversion circuit includes a power selection switch stage 101 for selecting AC power through the connector 100, as shown in FIG. It consists of the SMPS transformer 102 which makes the power output from the selection switch stage 101 into a predetermined power supply.

Referring to the operation of the conventional AC 110V / 220V automatic conversion circuit configured in this way in detail as shown in the AC power through the connector 100 is input to the power selection switch stage 101.

The power selection switch stage 101 selects and outputs power by a switch J1 or J2 selected by a user.

If you want to select AC 110V, you can connect select switch to J1 switch. If you want to select AC 220V, connect select switch to J2 switch.

The power converted by such power selection is output through the SMPS transformer 102 at an AC voltage of a predetermined level.

However, in the conventional AC 110V / 220V automatic conversion circuit, when the power selected by the user is not input, the system malfunctions due to low voltage, and when the user incorrectly selects the power, the system is damaged. There was this.

Accordingly, an object of the present invention is to provide an AC 110V / 220V automatic conversion circuit to prevent malfunction of the system and system damage caused by low and high voltages caused by misuse by the user.

The object of the present invention is achieved by detecting the voltage output from the SMPS transformer, and accordingly the voltage detection and display unit for displaying the state by driving the LED according to the present invention in detail with reference to the accompanying drawings as follows. same.

2 is a block diagram of an AC 110V / 220V automatic conversion circuit according to the present invention. The line filter unit 1 removes and outputs noise of an input AC voltage, and the AC voltage output from the line filter unit 1 is a predetermined voltage. The rectifying and smoothing part 3 rectifies the AC voltage outputted from the SMPS transformer 2 and the AC voltage outputted from the SMPS transformer 2 by the bridge diode 3a and smoothes the capacitor C1 to form a DC voltage of a predetermined band. ), And a voltage detection and display unit 4 for detecting the voltage output from the rectifying and smoothing unit 3 and the result thereof by emitting light to the light emitting diodes LED1 to LED2.

The operation and effects of the present invention AC 110V / 220V automatic conversion circuit configured as described above will be described in detail with reference to FIG. 3. As shown in FIG. 2, the line filter unit 1 removes noise from an input AC voltage. To print.

The AC voltage thus output is converted into a predetermined voltage by the SMPS transformer 2, and the converted voltage is input to the rectifying and smoothing unit 2.

Accordingly, the rectifying and smoothing unit 3 full-wave rectifies the input AC voltage to the bridge diode 3a, and smoothes the full-wave rectified AC voltage to the capacitor C1 to form an arbitrary DC voltage.

The voltage converted into the DC voltage in this manner is input to the voltage detection and display unit 4, and the voltage detection and display unit 4 is set through the variable resistor VR1 set after the resistor R3 as shown in FIG. 3. The switching element TR1 is turned on.

As the switching device TR1 is turned on, the DC voltage flows sequentially through the light emitting diode LED1 and the resistor R2 to the emitter of the switching device TR1, thereby causing the light emitting diode LED1 to emit light. do.

The voltage flowing to the emitter of the switching element TR1 becomes a constant voltage to the zener diode ZD1 and is input to the non-inverting terminal (+) of the comparator CP1 and the non-inverting terminal (+) of the comparator CP2, respectively. .

Here, the battery voltage Vbat divided by the resistors R6 and R7 is input to the inverting terminal (-) of the comparator CP1 and the resistors R9 and R10 to the inverting terminal (-) of the comparator CP2. The divided battery voltage Vbat is input.

Accordingly, the comparator CP1 compares the voltages of the two terminals (+,-) and outputs the result value, wherein the output condition of the comparator CP1 is that the voltage of the non-inverting terminal (+) is the inverting terminal (-). If the voltage is greater than the voltage, the output is high. On the contrary, if the voltage of the non-inverting terminal 1 is smaller than the inversion terminal (-) voltage, the output is low.

Under the above conditions, when the output of the comparator CP1 is high, the switching element TR2 is turned on so that a current flows in the relay RY, thereby driving the relay RY.

On the contrary, when the output of the comparator CP1 is low, the switching element TR2 is turned off so that the relay RY is not driven.

In addition, when the input DC voltage DCIN is smaller than the set variable resistance VR1, the switching device TR1 is turned off due to the lack of the turn-on voltage of the switching device TR1.

In addition, the comparator CP2 also outputs high when the non-inverting terminal (+) input voltage is greater than the voltage input to the inverting terminal (-). Will output the voltage.

When the output of the comparator CP2 is high, the switching element TR2 is turned off because it is inverted through the inverter INV and becomes low, and the high voltage sequentially turns the resistor R11 light emitting diode LED2 into order. The light emitting diode LED2 emits light when it flows through, and when the light emitting diode LED2 emits light, an abnormality of an input voltage is indicated.

As described in detail above, the present invention cuts the voltage supplied to the system even when it is incorrectly contacted due to an incorrect selection of AC 110V / 220V, so that the system protection and malfunction can be prevented.

Claims (1)

A line filter unit 1 for removing noise of an input AC voltage, an SMPS transformer 2 for converting an AC voltage output from the line filter unit 1 into a predetermined AC voltage, and an output from the SMPS transformer 2 Rectifying and smoothing the rectified and smoothed AC voltage to make a predetermined DC voltage, and the DC voltage obtained from the rectified and smoothed portion (3) is detected and the light emitting diode is driven to the resulting value to the external voltage AC 110V / 220V automatic conversion circuit, characterized in that it comprises a voltage detection and display unit (4) for indicating the status.