KR100427052B1 - Circuit breaker using positive temperature coefficent thermister - Google Patents

Abstract

The present invention is to provide a circuit breaker using a constant temperature thermistor that the reverse load resistance is increased due to the increase in the temperature of the element having a resistance sudden change when the inrush current occurs to block the current flow to the load side electronically. A second blocking unit configured to mechanically block the input power when the predetermined condition is reached after the primary blocking operation is performed; A primary blocker having a plurality of channel elements having a resistance sudden change point so that the reverse load resistance is increased by self-heating due to the current passing through the secondary blocker to offset the current flow of the input power source; A voltage detection-rectification circuit unit configured to detect and rectify a voltage applied to the load side through the primary blocking unit; A temperature detector configured to detect a temperature of a specific channel element of the primary blocker, and cut off power input to the primary blocker when a temperature exceeding a set level is detected; When the voltage output of the voltage detection-rectification circuit part and the temperature detected by the temperature detection part fall within a certain range, the secondary blocking control part is configured to shut off the secondary blocking part. Possible and easy capacity change.

Description

Circuit Breaker Using Constant Temperature Thermistor {CIRCUIT BREAKER USING POSITIVE TEMPERATURE COEFFICENT THERMISTER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker, and more particularly, to a circuit breaker using a constant temperature thermistor for interrupting inrush current by a series load sensing method.

In general, a circuit breaker is a kind of safety device designed to open and close a circuit manually in a normal circuit state, and to automatically cut off a circuit in an abnormal state such as a short circuit. Wiring breakers can be used to prevent fire, property damage and human injury due to short circuit, over current or short circuit.

The types of circuit breakers mainly used include 2-pole 2-element single-phase 2-wire and 3-pole 3-element 3-phase 3-wire.

Hereinafter, terms related to the operation of the circuit breaker will be described.

A short circuit (or short circuit) is a condition where the load-side current is infinite and the voltage is 0V. At this time, a rapid inrush current is generated.

Image current (leakage current) is a current that flows when indoor wiring or electrical appliances insulates the earth.

A short circuit is a state in which a leakage current flows due to a defective distribution line. In general, since the distribution line is grounded in one phase, when an insulation failure occurs on the load side of the commercial power supply 220V, a leakage current of about 5 to 100 mA flows depending on the ground resistance. Since such leakage current appears only on one side, an output proportional to the leakage current is obtained.

Overcurrents are currents above the rated current of the appliance (eg 30 A).

The blocking condition is a condition in which an input power is cut off due to a short circuit, an overcurrent, a short circuit, or the like, that is, a condition in which a breaker is operated.

The prior art of a circuit breaker is as follows.

Utility model 2002242420000 (2001.03.07.): Trip device for a circuit breaker.

Utility No. 2002579970000 (Dec. 6, 2001): Multifunctional circuit breaker.

Patent No. 1000070580000 (October 22, 1979): Circuit breaker.

Patent application No. 1997-0025632 (June 19, 1997): Inrush current prevention circuit of a mechanical microwave oven.

Patent application No. 1998-7001851 (March 12, 1998): overcurrent protection circuit.

Patent application No. 2000-0060886 (2000.10.17.): Circuit breaker.

In general, the main characteristics required for wiring breakers are speed and accuracy.

Current circuit breakers are usually operated by ODP (Oil Dash Pot) or thermoelectric type. These circuit breakers have the advantage of being operated quickly, but have the disadvantage of slow speed corresponding to instantaneous short circuit, overcurrent and overload. In case of short-circuit, a large flame and explosion occurs, and there is a difference in current control speed in case of over current or overload, which may cause fire or breakage of electric products.

As a result, thousands of electrical safety incidents per year occur. Therefore, the development of a circuit breaker for more stable and accurate operation is required.

Here, a representative technique for implementing a blocking function using a positive temperature coefficent, a thermally sensitive resistor, hereinafter referred to as a 'PTC thermistor' will be described.

The PTC thermistor is n-type which has conductivity by adding a small amount of rare earth element to barium titanate (BaTiO3), and replaces part of barium (Sb) with strontium (Sr) or lead (Pb) to allow the Curie temperature to be moved. A type of oxide semiconductor, which is defined as a device having a property of rapidly increasing the resistance value as the temperature rises due to phase transition. When the current flows for a very short time, the electrical resistance is increased so that the current does not flow, and it is also applied to the application of a TV shadow mask (element of the shadow mask), the motor start of the air conditioner.

The reverse polarity of PTC thermistors is the NTC thermistor (Negative Temperature Coefficent Thermistor).

For example, according to the inrush current prevention circuit of the mechanical microwave oven of patent application No. 1999-002105, the cement resistor is changed to a PTC thermistor and the self-response time of the DC relay is extended to prevent the inrush current from flowing to the load side. In operation of PTC thermistor, if the DC relay does not respond to its own response speed or becomes longer than the response speed due to a fault or malfunction of DC relay, it flows through PTC thermistor for a long time without going through DC relay switch. The thermistor will generate heat. Then, the PTC thermistor acts as a fuse by blocking the current flow by reaching the Curie temperature due to its own characteristic, that is, the resistance value increases with increasing temperature.

In the above-mentioned prior art, the function of blocking inrush current is achieved by using a PTC thermistor. However, in order to configure a circuit breaker installed between the power supply side and the load side to block inrush current, safety against failure or malfunction of the corresponding PTC thermistor must be ensured. For example, the PTC thermistor should have a separate blocking function to compensate for the electronic blocking operation as well as to compensate for this. In order to block the large current flowing through the power distribution line, the device characteristics of the PTC thermistor should be improved.

As described above, a conventional circuit breaker operating by ODP or thermoelectric type has a disadvantage of slow response to instantaneous short circuit, overcurrent and overload, and the prior art of blocking inrush current using a PTC thermistor is caused by an abnormality of the PTC thermistor. There is a technical limitation that does not fundamentally block the inrush current of the load side.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to increase the reverse load resistance at the resistance sudden point when an inrush current occurs so that the current inflow to the load side is electronically blocked. A circuit breaker using a constant temperature thermistor is provided.

The circuit breaker using the constant temperature characteristic thermistor of the present invention for achieving the above object comprises a secondary breaker to mechanically block the input power when a predetermined condition is reached after the primary break operation; A primary blocking unit having a plurality of channel elements having a resistance sudden change point so that a reverse load resistance is increased due to self-heating caused by the current passing through the secondary blocking unit to offset the current flow of the input power source; A voltage detection-rectifying circuit unit configured to detect and rectify a voltage applied to the load side through the primary blocking unit; A temperature detector configured to detect a temperature of a specific channel element of the primary blocker, and cut off power input to the primary blocker when a temperature exceeding a predetermined level is detected; And a secondary blocking controller configured to block the secondary blocking unit when the voltage output of the voltage detecting and rectifying circuit unit and the detected temperature of the temperature detecting unit fall within a predetermined range.

1 is a block diagram of a circuit breaker using a constant temperature thermistor according to an embodiment of the present invention.

Figure 2 is a cross-sectional view showing a detailed structure of the channel element in the primary blocking unit according to an embodiment of the present invention.

Figure 3 is a perspective view of the channel element in the primary blocking unit according to an embodiment of the present invention.

Figure 4 is a diagram showing the resistance-temperature characteristics of the constant temperature characteristic thermistor associated with the present invention.

Figure 5 is a diagram showing the current-voltage characteristics of the constant temperature characteristic thermistor associated with the present invention.

Figure 6 is a diagram showing the current-time characteristics of the constant temperature characteristic thermistor associated with the present invention.

Figure 7 is a schematic diagram showing the arrangement of each channel element in the primary blocking unit according to an embodiment of the present invention.

8 is a detailed view of the structure layer in the primary blocking portion according to the embodiment of the present invention.

9 and 10 are various thyristor circuit diagrams to which the present invention is applied.

<Description of Symbols for Main Parts of Drawings>

110: power input unit 120: secondary breaker

130: primary breaker 140: load side

150: voltage detector 160: rectifier circuit

170: secondary blocking control unit 180: temperature detection unit

210: P-channel device 220: N-channel device

231, 233: P terminal 232, 234: N terminal

240: insulation plate 250: load control terminal

Unlike the interruption method of a conventional circuit breaker such as a thermally movable type, the present invention is a serial load sensing method for detecting a serial load by connecting to a power input terminal in series. The series load detection method utilizes Curie temperature, that is, the rapid load resistance increases rapidly as the temperature rises, that is, it is specially processed as a bidirectional device by using the resistance sudden change point so that it can be utilized as the reverse load resistance device in case of short circuit, over current, and overload. It uses the principle of operating according to load current by connecting in series.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

According to FIG. 1 showing a block configuration of a circuit breaker using a constant temperature characteristic thermistor, the circuit breaker shuts down the input power when a predetermined condition is reached after the power input unit 110 for receiving power and the first blocking operation is performed. The secondary blocking unit 120, which has a P-channel device and an N-channel device having a resistance change characteristic according to the current change to offset the current passing through the secondary breaker 120 to the resistance rapidly changed at the resistance break point Rectification for rectifying the AC voltage detected by the voltage detection unit 150 and the voltage detection unit 150 through the primary blocking unit 130, the primary blocking unit 130 to the voltage applied to the load side The temperature detector for detecting the temperature according to the heating of the P-channel element of the circuit unit 160, the primary circuit breaker 130, and the voltage output of the rectifier circuit unit 160 and the detected temperature of the temperature detector 180 are in a predetermined condition. When it reaches the secondary blocking unit 120 It is configured to include a secondary blocking control unit 170 for blocking.

Input power is supplied to the load 140 side through such a blocking device.

The power input unit 110 is a part for receiving AC power of single-phase two-wire 220V or three-phase three-wire 390V as a drawing means of power to be supplied to the load 140 side. Here, the case of using a 220V electrical appliance connected to the load 140 side, that is, a case where a commercial power of a single-phase two-wire 220V is supplied will be described.

The secondary blocking unit 120 performs the primary blocking operation performed by the primary blocking unit 130 under the control of the secondary blocking control unit 170 when a blocking condition (overcurrent, short circuit, short circuit, etc.) is established. Secondarily cut off the input power.

The primary blocking unit 130 reacts by rapidly increasing the reverse load resistance at the resistance change point according to the passing current, and includes a P-channel device 210 and an N-channel device 220 for each feed line. The P-channel device 210 and the N-channel device 220 are reverse polarity devices. The P-channel device of the primary blocking unit 130 may be implemented using a commercial PTC thermistor, and the N-channel device 220 may be implemented using an NTC thermistor.

P-channel device 210 immediately increases the resistance change point when the current increases to cancel the voltage and current. When the N-channel device 220 decreases the resistance sudden change as compared with the speed of the P-channel device 210 when the current increases, the secondary blocking control unit 170 operates the secondary blocking unit 120 so that the double blocking is performed. do.

Therefore, the N-channel device 220 is designed to have a low resistance sudden point arrival time and a slightly higher resistance value than the P-channel device 210. When applied to a commercial power supply, the operating temperature of the N-channel element 220 may be set to about 150 degrees at maximum, and the operating temperature of the P-channel element 210 may be set to about 70 degrees at maximum.

2 and 3, the primary blocking unit 130 is positioned between the P-channel device 210, the N-channel device 220, the P-channel device 210, and the N-channel device 220. An insulating plate 240 to insulate the devices, and P terminals 231 and 233 and N terminals 232 and 234 for connecting the respective channel elements of the P and N channels to the conductive lines, and the P channel element 210. It is configured to include a load control terminal 250 for detecting a current passing through. The primary blocking unit 130 may be implemented using a module having each of these components.

Referring to FIG. 4, when the resistance-temperature characteristic is determined by measuring the electrical resistance according to the change in the ambient temperature of the PTC thermistor, a temperature (resistance point temperature or Curie temperature) Tc at which the resistance value is rapidly increased appears. In general, the Curie temperature is defined as the temperature corresponding to twice the minimum resistance value or the reference temperature resistance value.

Referring to Fig. 5, when the current-voltage characteristic of the PTC thermistor is applied, if the voltage is gradually increased by applying a voltage to the PTC thermistor, the temperature of the element rises due to self-heating and reaches near the Curie temperature. As a result, a decrease in current appears. On the other hand, if the voltage applied to the device exceeds a certain value, the current value also increases rapidly as the voltage increases, leading to breakdown. This voltage is called breakdown voltage (Vb).

Referring to Fig. 6, the current-time characteristic of the PTC thermistor will be described. When a predetermined current flows through the PTC thermistor, the resistance value rapidly increases due to self-heating to limit the current. As described above, a property in which a large current flows initially and then attenuates and is suppressed to a micro current is a characteristic that is suitable for use for preventing overcurrent as a heating element having a rapid temperature rise.

The voltage detector detects whether an AC voltage is output from the load side connection terminal (or output terminal) of the P-channel device 210 in the primary blocking unit 130.

The rectifier circuit 160 rectifies the AC voltage detected by the voltage detector to generate a DC voltage. The rectified DC voltage is applied to the secondary blocking controller 170.

In addition, the secondary cutoff control unit 170 includes an overcurrent control circuit, an amplifier circuit, an electric leakage control circuit, a short circuit control circuit, a temperature sensing circuit, a delay circuit, and the like.

The amplifier circuit is implemented with a plurality of driving amplifiers (OP-AMP).

The overcurrent control circuit is intended to cope with the case where the gradually increasing current exceeds the rated current, not the instantaneous overcurrent, and operates the amplifier stepwise in accordance with the temperature detected by the temperature detector.

For example, if the detected temperature of the temperature detector corresponds to 30/40/50 degrees for the load-side supply current 30/40 / 50A, respectively, the overcurrent control circuit operates the amplification circuit in steps of 30/40 / 50A so that the light emitting diode ( LEDs) can be displayed step by step (e.g. 30A green, 40A orange, 50A red).

The earth leakage control circuit operates the amplifying circuit according to whether or not a DC voltage is output from the rectifying circuit unit 160 to turn on / off the secondary blocking device. When a short circuit occurs, when the primary breaker 130 is not normally operated and a DC voltage is output from the rectifier circuit 160, the secondary breaker 120 is turned off by the earth leakage control circuit, and the primary breaker 130 is In normal operation, since the DC voltage is not output from the rectifying circuit unit 160, the secondary blocking unit 120 is turned on by the earth leakage control circuit.

For example, according to the ground voltage limit of indoor converters, the earth leakage breaker should be less than 30mA of rated sensitivity current and less than 0.03 seconds of operation time in current operated and high speed type. The blocking device according to the present invention may be designed to meet these criteria by varying the resistance break point temperature of the primary blocking unit 130 and the secondary blocking temperature of the ground fault control circuit.

The short circuit control circuit controls the secondary breaker 120 on / off after causing a delay for a predetermined time through the delay circuit according to the operation state of the primary blocker 130 when a short circuit occurs. In the short circuit, since the operating voltage of the P-channel device 210 in the primary blocking unit 130 is 0 V, the detection voltage of the voltage detecting unit 150 becomes 0 V, and after delayed by the delay circuit, the secondary blocking unit 120 ) Is off.

The delay circuit protects the load 140 by securing an appropriate delay time when the input voltage is automatically supplied again in a state in which the input voltage is cut off by the secondary blocking unit 120. In the overcurrent, short circuit, or short-circuit state, the input voltage is cut off. At this time, if the input voltage is immediately resupplied, a fatal problem may occur in the electronic device (air conditioner, refrigerator, etc.) of the load side 140. Therefore, the load side 140 is protected during automatic return by securing an appropriate delay time (for example, 3 to 5 minutes) by using a delay circuit when supplying voltage again.

The temperature sensing circuit performs stepwise determination of an overcurrent state according to the temperature detected by the temperature detector 180, and prevents each channel element of the primary blocking unit 130 from overheating during a short circuit. For example, if the temperature of the P-channel device 210 rises to about 65 to 70 degrees by leaving the short circuit state of the load side 140 supplied with commercial power, the temperature sensing circuit detects this to detect the secondary blocking unit 120. Turn it off.

In this way, in addition to the primary blocking unit 130 that operates at the resistance break point, the secondary blocking unit 120 is provided at the front end thereof.

That is, the secondary breaker 120 is provided to prevent an overcurrent from flowing into the load side 140 when an abnormality occurs in the primary breaker 130. Since the secondary blocking unit 120 is intended to complement the primary blocking unit 130, it is preferable to implement the secondary circuit breaker 120 using an existing circuit breaker designed to directly perform a power blocking function. As a result, the reliability of the blocking device can be increased by taking advantage of the advantages of the existing blocking method.

Conventional methods include thermoelectric and ODP methods, which do not work properly at currents below the rated capacity. If the load voltage is not detected using this characteristic, the secondary breaker 120 may be cut off (or OFF). In this embodiment, the secondary breaker 120 is controlled by the voltage supplied from the load control terminal 250. Make blocking operation of.

Here, the blocking operation according to each blocking condition will be described based on the case where the secondary blocking unit 120 is implemented as the magnet breaker.

First, the operation corresponding to the overcurrent will be described. When the electrical appliance is used at a rated current (eg, 30 A) or more, that is, in an overcurrent state, the P-channel element 210 of the primary blocking unit 130 gradually reaches a resistance break point, thereby performing a primary blocking operation. Primary blocking is an operation in which the input load resistance of the P-channel device 210 rapidly increases and the electronic input power is cut off. When the primary block is made like this, the voltage is also 0 V because there is no output current to the load side 140. That is, the detected voltage of the voltage detector 150 and the DC voltage of the rectifier circuit 160 become 0V. Therefore, the delay circuit of the secondary blocking control unit 170 is operated and the secondary blocking unit 120 is turned off. At this time, the N-channel device 220 operates a little higher than the P-channel device 210, and the response speed is also slow.

The operation corresponding to the leakage current (leakage) will be described. In the case of the commercial power supply, the leakage current due to the poor insulation of the load side 140 appears only on one side, so that the output terminal voltage of the primary breaker 130 is proportional to the leakage current. When the voltage due to the leakage current is detected by the voltage detector 150, the earth leakage control circuit of the secondary blocking controller 170 turns off the secondary blocking unit 120.

The operation corresponding to the paragraph will be described. When a momentary inrush current is generated due to a short circuit, the P-channel element 210 of the primary blocking unit 130 instantaneously reaches the resistance sudden change point so that the reverse load resistance rapidly increases to block the inrush current. In general, since there is a risk of fire due to a call (spark) when the instantaneous resistance value is increased, for example, the P-channel device 210 decreases to 120 mA within 3 seconds when the inrush current of 30 A occurs, and then gradually decreases to 8 mA within 180 seconds. do. This cuts off the instantaneous inrush current without large resistance.

Looking at the primary cut-off operation when the load side 140 is short-circuited, the N-channel device 220 can be properly implemented according to the operating environment, for example, the maximum instantaneous current 50A, the time current 10 seconds, the operating temperature -30 ~ 150 Designed to have the characteristics of FIG. Can be applied to commercial power (220V). The N-channel device 220 is connected in parallel with the P-channel device 210 to operate so that a high current is supplied to the load side 140. The N-channel device 220 functions to keep the P-channel current constant when constant current is supplied in inverse proportion to the current.

As such, the P-channel device 210 first responds when the load side 140 is short-circuited to increase the reverse load resistance. Therefore, when the primary block is made, the voltage of the load control terminal 250 becomes 0 V, so that the magnet of the secondary block unit 120 is turned off so that the input power is cut off twice.

In addition, when an instantaneous short circuit is repeated twice as an example, the temperature rise of the primary blocking unit 130 is detected. When the temperature detector 180 detects a temperature increase of the primary blocker 130, the temperature detection unit 180 maintains the specified temperature range by forcibly shutting off the input power in parallel with the block operation of the primary blocker 130. . Forced blocking by the temperature detector 180 is maintained until the primary blocking unit 130 is maintained at a prescribed temperature.

In addition to the automatic return of the secondary blocking unit 120, it is also possible to manually turn off the secondary blocking unit 120 according to the user's selection.

Next, a design method for making the primary blocking unit 130 suitable for a large current will be described.

Since a general PTC thermistor is for low current, the primary blocking unit 130 should be suitable for large current to achieve a blocking function in a distribution line.

Fig. 7A shows the PTC thermistors connected in parallel. According to this, although each PTC thermistor has a low current capacity, it is possible to design a large current as a whole of the primary blocking unit 130, to easily implement heat treatment of the PTC thermistor, and to maximize the characteristics of the PTC thermistor.

In the case of designing the primary blocking unit 130 by the parallel connection method, the resistance value of the PTC thermistor, the Curie temperature (resistance sudden change point), the total resistance value against the instantaneous inrush current at the time of short circuit, the heat radiation structure at the resistance sudden change point, Consideration should be given to equal current distribution between PTC and PTC.

FIG. 7B shows a series design of the PTC thermistor and the NTC thermistor in parallel. In the primary blocking unit 130, the PTC thermistor is used as a P-channel device, and the NTC thermistor is used as an N-channel device.

The parallel and parallel design method has advantages such as surge protection of input voltage, device protection in case of load short, and inrush current distribution in case of load short. In this method, the resistance value, current, and temperature of the PTC thermistor and the NTC thermistor must be summed in the design of the primary blocking unit 130.

7 (c) shows that a PTC thermistor and an NTC thermistor are connected in parallel. This parallel connection design prevents the PTC thermistor from rising and can be used as a variable PTC thermistor in parallel with the NTC thermistor.

The structure of the primary blocking unit 130 can be designed by applying various design methods as described above.

8 shows an example of the structure layer of the primary blocking unit 130. As shown in Fig. 8A, the PTC thermistor 41 and the NTC thermistor 42 are arranged in close proximity, and the heat dissipation structure 43 and the ventilation opening 44 are provided. According to the arrangement of the PTC thermistor 41 and the NTC thermistor 42, it is possible to freely select and change the parallel or serial parallel method as described above. In addition, it is provided with a through-hole 45 for the support bolt for fastening the support bolt as needed.

Such a structure layer can be manufactured in a large annular shape and designed for each floor. As shown in FIG. 8 (b), a printing having a copper plate surface 51 and a ventilation hole 53 corresponding to each thermistor 41 and 42 is provided. It can be laminated on a circuit board. Optionally, a rectangular or hexagonal structure layer can be designed. Figure 3 shows an application example of the rectangular structure layer.

By stacking the structure layer, the current capacity can be increased, and the current capacity can be varied according to the stacking degree. In addition, the thickness of the PTC thermistor 41 and the NTC thermistor 42 may be controlled to have various characteristics in the design of the structure layer.

These examples can be applied to perform short circuit tests.

For example, the test results at 25 ° C, 130 ° C Curie temperature, and 2.2 A (500 W) load are shown below.

1) Temperature 28 ° C (3 ° C rise) in the 1st momentary short-circuit-Temperature measurement outside the heat dissipation structure (The internal temperature of the PTC thermistor has reached the Curie temperature due to a short circuit).

2) Increased 1 degree every 1 sec. If short-circuited for 25 seconds, it will rise to 50 degrees and the secondary cutoff control will be activated.

3) Automatic return after delay of 3 minutes for 1st moment short circuit

4) Automatic recovery after delay of 5 minutes in the second short circuit

5) Temperature rise is detected by the temperature detector 180 at the third instantaneous short circuit. Since the secondary blocking unit 120 operates to turn off the load, automatic return is impossible. At this time, power is not supplied even if forced return. Then, the temperature detection unit 180 operates to forcibly block until the temperature is maintained at a predetermined temperature (25 to 30 degrees).

As such, the primary blocking unit 130 that operates electronically is a departure from the conventional method. Therefore, if a general low voltage circuit breaker is implemented, it can be easily applied to various current leakage circuit breakers, circuit breakers, and circuit breakers. For example, it can be applied to various products described in the industry-leading breaker series reference materials.

9 and 10 show various thyristor circuits for protecting the load side 140 when a blocking condition occurs, which can be replaced with a blocking device according to the present invention to further improve safety and reliability thereof. In Fig. 7, (a) is an overcurrent protection circuit, (b) is an overvoltage protection circuit, and (c) is a gate overvoltage protection circuit, in which the portion indicated by reference numeral 700 is replaced with a blocking device according to the present invention. Can be. 8A to 8I show examples of the configuration of various surge voltage protection circuits, in which portions indicated by reference numeral 800 may be replaced by the blocking device according to the present invention. Various other applications are envisioned.

Illustrative application fields of the present invention are as follows.

① Short circuit breaker, wiring breaker, short circuit breaker and wiring breaker: single phase 2-wire or 3-phase 3-wire

② Thyristor protection for power control: short circuit, over current, overload, load power control

③ Prevent overload, over current and short circuit of electrical outlet

④ For electric and electronic products, communication equipment, medical equipment, automobiles, PLC (power level controller): overload, over current, short circuit prevention

⑤ Available for power control detection sensor (analog-digital): load voltage is detected in proportion to the load current and not indirect but in series (no current transformer required)

⑥ Can be used as a semi-permanent fuse in case of short circuit, over current and overload

The embodiments described above are within the scope of various changes, modifications, and equivalents of the present invention. Therefore, the present invention is not limited to the description of the examples.

According to the circuit breaker using the constant temperature characteristic thermistor of the present invention has the following effects.

First, the conventional circuit breaker is fired at the moment of short-circuit to cause flame and explosion, and there is a risk of fire due to this. .

Second, the conventional circuit breaker has a problem that the electrical product is damaged because the rated current is not controlled at the moment of instantaneous overcurrent, but the circuit breaker according to the present invention prevents damage to the electrical product because the current circuit can be instantaneously controlled.

Third, the conventional circuit breaker operates only when the rated capacity is exceeded, so that the circuit breaker according to the present invention has a disadvantage in that it is replaced by a shortage of the rated capacity. Changeable use is not required, so no replacement is required to change capacity.

In addition, it can be applied to next generation power line control remote power supply system to protect the load side during power supply.

Claims (5)

A secondary blocking unit configured to mechanically block the input power when a predetermined condition is reached after the primary blocking operation is performed; A primary blocking unit having a plurality of channel elements having a resistance sudden change point so that a reverse load resistance is increased due to self-heating caused by the current passing through the secondary blocking unit to offset the current flow of the input power source; A voltage detection-rectifying circuit unit configured to detect and rectify a voltage applied to the load side through the primary blocking unit; A temperature detector configured to detect a temperature of a specific channel element of the primary blocker, and cut off power input to the primary blocker when a temperature exceeding a predetermined level is detected; And a secondary blocking control unit configured to block the secondary blocking unit when the voltage output of the voltage detecting and rectifying circuit unit and the detected temperature of the temperature detecting unit fall within a predetermined range. . The method of claim 1, wherein the primary blocking unit, A P-channel device made of a static thermistor whose resistance increases rapidly at the resistance sudden change point when the current increases; An N-channel device adapted to have the reverse polarity of the P-channel device; And a insulating means configured to insulate between the P-channel element and the N-channel element. The method of claim 2, The primary blocking part is formed by stacking a plurality of structure layers, wherein the structure layer includes a heat dissipation structure for dissipating heat emitted by the P channel elements and the N channel elements and the respective channel elements. A circuit breaker using a constant temperature thermistor. The method of claim 1, wherein the secondary blocking control unit, An amplifying circuit unit having a plurality of stages of amplifying elements for amplifying various control signals to operate the secondary blocking unit; An overcurrent control circuit unit for controlling an amplification degree of the amplifying element step by step to operate a predetermined display means step by step so that an indication of an overcurrent state is achieved; An earth leakage control circuit unit for performing an earth leakage judgment according to whether the output voltage of the rectifier circuit unit exceeds a predetermined level and applying a signal to the amplification circuit unit to control a blocking operation of the secondary blocking unit; A short-circuit control circuit section for performing a short-circuit judgment according to whether the output voltage of the rectifying circuit section is 0 V to apply a signal for controlling the blocking operation of the secondary cut-off section to the amplifying circuit section; Constant temperature characterized in that it comprises a temperature sensing circuit for controlling the over-current control circuit unit by performing the step-by-step determination of the over-current state in accordance with the detected temperature of the temperature detector, and to prevent overheating of each channel element in the primary blocking unit. Circuit breaker using characteristic thermistor. The method of claim 4, wherein the secondary blocking control unit, And a delay circuit unit for protecting the load side by delaying the resupply of the input power by a predetermined time during the automatic return to the on state from the off state of the secondary breaker. .