KR100625171B1 - A device for preventing overcurrent - Google Patents

Abstract

The present invention relates to an overcurrent prevention device, and when an overcurrent flows in a system, the sensor unit detects this and converts a current into a voltage to output a voltage signal. The comparator compares the voltage signal with a reference voltage ref, and outputs a comparison signal in a low state when the voltage signal is equal to or greater than the reference voltage ref. When the comparison signal is input in a low state, the integrated circuit unit outputs a switching signal corresponding to the high state without time delay to control switching and cut off the overcurrent. By doing so, it is possible to prevent damage to the system and to prevent overcurrent at low cost.

Overcurrent, sensor, switching

Description

Overcurrent Protection Device {A device for preventing overcurrent}

1 is a block diagram of an overcurrent prevention device according to an embodiment of the present invention.

2 is a view showing the waveform of each part of the overcurrent protection device according to an embodiment of the present invention.

The present invention relates to an overcurrent prevention device, and more particularly, to an overcurrent prevention device installed in a power supply, a charger, various power products, and an electronic device to prevent an overcurrent flowing inside the product.

In the conventional switching mode or linear method, when an overcurrent is detected, there is a limit, a decrease, or an increase in the continuous current increase on the output side.

In addition, in the case of the constant current type, the current mode method, the voltage mode method, the a descent method or the differential oscillation, the output current flows continuously.

If this condition is maintained continuously, unnecessary power may be supplied or the switch element or other parts may remain in a heating state, causing component damage, and when the switch element is switched to a short state, a large amount of shock current may flow in the circuit, causing a fire or circuit There is a risk of damage to the equipment or equipment, which makes the system difficult to operate normally.

If the overload condition is maintained, various problems may occur, leading to a state in which the reliability of the semiconductor switch element, the component, or the product itself cannot be obtained, which may result in loss of credibility both internally and externally, and may reduce the image of the product or the company.

As described above, an electrically operated product such as a power supply may damage the product due to an overcurrent flow, and thus a circuit or a device for preventing an overcurrent is required.

The technical problem to be achieved by the present invention is to provide an overcurrent protection device that blocks the current as soon as the overcurrent is detected so that no current is output.

In addition, the overcurrent protection device is implemented at a low cost.

An overcurrent prevention device according to one feature of the present invention for solving this problem,

A device for preventing overcurrent of a power system that outputs power.

A sensor unit for sensing a current of the power system and converting the voltage into a voltage to output a voltage signal;

A comparator comparing the voltage signal with a reference voltage and outputting a comparison signal corresponding to the comparison result;

An integrated circuit unit configured to output a switching signal corresponding to the comparison signal without a time delay;

A first switch operating according to a switching signal of the integrated circuit;

When the first switch is turned on, it comprises a second switch for shutting off the output power of the power system.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

First, an overcurrent prevention apparatus according to an embodiment of the present invention will be described with reference to FIG. 1.

1 is a block diagram of an overcurrent prevention device according to an embodiment of the present invention.

Referring to Figure 1, the overcurrent prevention apparatus according to an embodiment of the present invention,

An apparatus for preventing overcurrent of a power supply system 200 that outputs a power source, the sensor unit 120, a comparator 100, an integrated circuit unit 110, a resistor R, a capacitor C, a transistor Tr, Switch 130. The sensor unit 120 detects the current of the power system 200 and converts the voltage into a voltage to output a voltage signal. The sensor 120 uses a hall sensor, a transformer, a detection resistor, or the like. The comparator 100 compares the voltage signal with a reference voltage ref, and outputs a comparison signal in a low state when the voltage signal is equal to or greater than the reference voltage ref. When the comparison signal is input in a low state, the integrated circuit unit 110 outputs a switching signal corresponding to the high state without a time delay. The resistor R and the capacitor C allow the output of the high state of the integrated circuit unit 110 to be maintained for a predetermined time. The transistor Tr is turned on according to the high state signal of the integrated circuit unit 110. When the transistor Tr is turned on, the switch 130 is turned off to block the output power of the power system 200.

In the embodiment of the present invention, in the structure in which the switch 130 is connected to the output terminal OUT + of the power supply system 200 to prevent overcurrent, and the sensor unit 120 is coupled, the sensor unit 120 and the comparator 100 ), The integrated circuit unit 110, the resistor R, the capacitor C, the transistor Tr, the switch 130, and the like are packaged and combined. In addition, the package can be configured in various ways, or in other forms.

The operation of the overcurrent protection device according to the embodiment of the present invention having such a configuration will be described in detail with reference to FIG. 2 as follows.

2 is a view showing the waveform of each part of the overcurrent protection device according to an embodiment of the present invention.

First, the power system 200 is a device for supplying power to the outside, and outputs a constant power through the output terminal.

Then, the sensor unit 120 detects the current of the power system 200 and converts it into a voltage to output a voltage signal, and performs this function using a hall sensor, a detection resistor, a transformer, or the like. At this time, the output waveform (a) of the sensor unit is shown in FIG.

Here, when an overcurrent occurs for some reason in the output terminal LOAD, the sensor unit 120 outputs an overload as shown in FIG.

Then, the comparator 100 compares the voltage signal with the reference voltage ref as the detected overload is input to the inverting terminal, and outputs a comparison signal in a low state since the overvoltage signal is greater than or equal to the reference voltage ref. The waveform (b) of is shown in FIG. At this time, the reference voltage (ref) of the comparator 100 is set in consideration of the point (Point) which is the reference of the overcurrent, and is designed to output a low state signal when the overvoltage (overcurrent point) is input.

When the comparison signal is input in a low state, the integrated circuit unit 110 outputs a switching signal corresponding to the high state without a time delay, and the output waveform c of the third terminal is shown in FIG. 2. In this case, the integrated circuit unit 110 is an NE555 IC having a timer, an oscillator, and the like. When the low signal is input to the second terminal, the integrated circuit unit 110 directly outputs the high signal to the third terminal without a time delay. Here, the NE555 IC may be replaced by an IC having the same structure or an IC having the same function regardless of the manufacturer. In addition, if a resistor (R) is connected to terminals 7 and 8 and a capacitor (C) is connected to terminal 6, the output value of the high signal is constant according to the values of the connected resistor (R) and capacitor (C). It will stay for hours.

When the high signal is output from the third terminal of the integrated circuit unit 110, the transistor Tr is turned on, the voltage of the collector is lowered to zero potential, and the waveform at this time is shown in FIG.

Then, the zero voltage of the collector of the transistor Tr lowers the base or gate of the switch 130 composed of the transistor to zero potential so that the switch 130 is turned off to block the current flow of the power supply system 200. At this time, the waveform in which the current is actually cut is shown in Figure 2, the hatched portion indicates that the current does not flow.

As can be seen in Figure 2 of the above process, in the embodiment of the present invention it is possible to cut off the power as soon as the overcurrent occurs, it may not damage the system.

In addition, referring to Figure 2, when the time that the terminal 3 of the integrated circuit unit 110 is maintained by the resistor (R) and the capacitor (C) has elapsed, if the overcurrent does not flow to return to the normal state, as shown in FIG. If the condition is generated or maintained, it will remain powered off.

In addition, the resistors R1 and R2 are provided for a load so that the output voltage of the integrated circuit unit 110 does not apply to the transistor Tr.

The above embodiments may be variously modified, and if necessary, the transistor Tr may be omitted, and the switch 130 may be controlled by the output of the integrated circuit unit 110.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit and scope of the present invention.

As described above, in the embodiment of the present invention, it is possible to provide an overcurrent prevention device that can cut off the current as soon as the overcurrent of the system is detected to prevent damage to the system, and can be implemented at a low cost.

Claims (7)

 A device for preventing overcurrent of a power system that outputs power. A sensor unit 120 for sensing a current of the power system and converting the voltage into a voltage to output a voltage signal; A comparator (100) for comparing the voltage signal with a reference voltage and outputting a comparison signal corresponding to the comparison result; An integrated circuit unit 110 outputting a switching signal corresponding to the comparison signal without a time delay; A first switch Tr operating according to a switching signal of the integrated circuit; When the first switch is turned on, it comprises a second switch 130 for shutting off the output power of the power system, The integrated circuit unit is a 555 IC, A resistor (R) connected between terminals 7 and 8 of the 555 IC, Further comprising a capacitor (C) connected to the number 6 terminal of the 555 IC, And the output of the third terminal of the 555 IC is delayed for a predetermined time according to the values of the resistor (R) and the capacitor (C). delete delete  The method of claim 1, The sensor unit is characterized in that any one of a Hall sensor, a detection resistor, a transformer, the over-current protection device, characterized in that for converting the current detected by the inverting terminal of the comparator to a voltage output.  The method of claim 1, The comparator 100 sets the reference voltage to output a low signal when the voltage input to the inverting terminal is greater than the reference voltage connected to the non-inverting terminal. delete  A device for preventing overcurrent of a power system that outputs power. A sensor unit 120 for sensing a current of the power system and converting the voltage into a voltage to output a voltage signal; A comparator (100) for comparing the voltage signal with a reference voltage and outputting a comparison signal corresponding to the comparison result; An integrated circuit unit 110 outputting a switching signal corresponding to the comparison signal without a time delay; And a switch 130 for cutting the output power of the power system according to the switching signal of the integrated circuit. The integrated circuit unit is a NE555 IC, A resistor (R) connected between terminals 7 and 8 of the 555 IC, Further comprising a capacitor (C) connected to the number 6 terminal of the 555 IC, And the output of the third terminal of the 555 IC is delayed for a predetermined time according to the values of the resistor (R) and the capacitor (C).

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