Abnormal external ultrahigh voltage input anti-shell-fusion circuit

Abstract

The invention, which relates to the technical field of the power adapter, discloses an abnormal external ultrahigh-voltage input shell-melting-prevention circuit comprising a power adapter shell, a circuit board, and an input rectification filtering unit. The input rectifying and filtering unit comprises a fuse F1, a fuse F2, a temperature fuse TF1, a lightning protection device piezoresistor MOV1 and an input electrolytic capacitor CX1; on the AC input side, a fuse F1 and a fuse F2 form a double-insurance circuit, a temperature fuse TF1 and a piezoresistor MOV1 form a series circuit, and the temperature fuse TF1 is tightly attached to the piezoresistor MOV1; through the circuit design of double insurance and introduction of the temperature fuse, multiple open-circuit protection is formed, and the risk of plastic shell fusion caused by short circuit of devices can be effectively avoided. An electrolyte absorption structure is arranged in the power adapter shell, when an electrolyte is sprayed out after a top explosion-proof valve of an input electrolytic capacitor CX1 is opened, the electrolyte is absorbed, and the situation that the electrolyte falls on a circuit to cause short-circuit heating or shell melting through caused by fire is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power adapter, in particular to an abnormal external super high voltage input anti-fusible circuit. BACKGROUND

[0002] The current power grid voltage is extremely unstable, and the phenomenon of continuous fluctuation or instantaneous jump occurs, especially in overseas markets such as India. The harm of unstable power grid voltage to the power supply system mainly reflects in equipment damage, data loss, system paralysis and other aspects. The specific influence is as follows: 1. Electronic component breakdown: high voltage can cause component burnout, such as transformer winding overheating or burnout; low voltage may cause the device to fail to start.

[0003] 2. Precise equipment failure: the photolithography machine of semiconductor enterprises is caused by voltage drop, resulting in wafer scrap, single loss exceeding 2 million yuan; medical equipment, industrial control system, etc. may cause program disorder or hardware damage due to voltage fluctuation.

[0004] 3. Data and system abnormalities Data loss: microelectronic devices such as computers are prone to hardware damage or system crash due to voltage surge / drop, which may cause data loss.

[0005] Device misoperation: industrial production equipment may trigger protection mechanism due to voltage fluctuation, resulting in unexpected shutdown or production interruption.

[0006] 4. Safety hazards: abnormal high voltage input from outside can cause internal pressure-sensitive burnout of power supply, and pressure-sensitive overheating can cause plastic shell to melt through. The internal electrolyte is ejected after the explosion-proof valve is opened, and the electrolyte is affected by high temperature and high pressure, which can also ignite the PCB and shell, causing property and life safety to consumers. SUMMARY

[0007] The present application is to overcome the above-mentioned deficiencies, and aims to provide an abnormal external super high voltage input anti-fusible circuit which can respond to avoid high temperature melting shell when abnormal external super high voltage input.

[0008] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: an abnormal external super high voltage input anti-fusible circuit, comprising a power adapter shell, a circuit board is arranged in the power adapter shell, and an input rectifier filter unit is arranged on the circuit board; The input rectifier filter unit comprises a fuse F1, a fuse F2, a temperature fuse TF1, a lightning protection device MOV1 and an input electrolytic capacitor CX1. The AC input side is composed of a double insurance circuit of fuse F1 and fuse F2, The temperature fuse TF1 and the pressure sensitive resistor MOV1 form a series circuit, and the temperature fuse TF1 and the pressure sensitive resistor MOV1 are close to each other and are kept close to each other by a sleeve in the power adapter shell, The power adapter shell is provided with an electrolyte absorbing structure, which is used to absorb the electrolyte when the electrolyte is sprayed after the explosion-proof valve at the top of the input electrolytic capacitor CX1 is opened.

[0009] As a further scheme of the present application, the electrolyte absorbing structure includes absorbing cotton arranged at the top of the input electrolytic capacitor CX1.

[0010] As a further scheme of the present application, the L side of the AC input side and the N side of the AC input side are covered with insulating glue.

[0011] As a further scheme of the present application, the temperature fuse TF1 and the pressure sensitive resistor MOV1 are close to the L side of the AC input side and the N side of the AC input side. When the L side of the AC input side and the N side of the AC input side are covered with insulating glue, the insulating glue simultaneously fixes the sleeve arranged on the temperature fuse TF1 and the pressure sensitive resistor MOV1, and forms a peripheral shaping and fastening of the sleeve.

[0012] As a further scheme of the present application, the power adapter shell includes an upper shell and a lower shell. The lower edge of the upper shell and the upper edge of the lower shell are covered to obtain the power adapter shell, and form a mounting space inside the power adapter shell. The part close to the inner side of the lower edge of the upper shell extends downward to form a first connecting frame corresponding to the inner side of the upper edge of the lower shell. The part close to the first connecting frame on the upper edge of the upper shell is concave upward to form a connecting groove, and the part close to the inner side of the upper edge of the lower shell extends upward to form a second connecting frame matched with the connecting groove. When the upper shell and the lower shell are engaged, the second connecting frame is inserted into the connecting groove, and the first connecting frame is inserted into the lower shell along the inner side of the upper edge of the lower shell. Then, ultrasonic welding is used to weld the first connecting frame and the inner side of the upper edge of the lower shell together, and to weld the second connecting frame and the inner wall of the connecting groove together, forming a double stop connection structure.

[0013] As a further scheme of the present application, the input rectifying filter unit further includes a common mode inductor LF1, a rectifier bridge BD1, and a thermistor NTC1. One end of the fuse F1 is connected with the L side of the AC input side, the other end of the fuse F1 is connected with one end of the temperature fuse TF1, the other end of the temperature fuse TF1 is connected with one end of the fuse F2, the other end of the fuse F2 is connected with one end of the first group winding LF1B of the common mode inductor LF1, the other end of the first group winding LF1B of the common mode inductor LF1 is connected with the first input end of the rectifier bridge BD1, One end of the pressure sensitive resistor MOV1 is connected at the common pressure point of the temperature fuse TF1 and the fuse F2, the other end of the pressure sensitive resistor MOV1 is connected with the N side of the AC input side, one end of the thermistor NTC1 is connected with the other end of the pressure sensitive resistor MOV1, the other end of the thermistor NTC1 is connected with one end of the second group winding LF1A of the common mode inductor LF1, The other end of the second group winding LF1A of the common mode inductor LF1 is connected with the second input end of the rectifier bridge BD1, One end of the input electrolytic capacitor CX1 is connected with the other end of the fuse F2, the other end of the input electrolytic capacitor CX1 is connected with the other end of the thermistor NTC1.

[0014] Compared with the prior art, the beneficial effects of the technical scheme are that the first stage F1 can withstand large surge lightning current, and the second stage fuse F2 can timely play a protection role when the abnormality occurs in the subsequent stage circuit.

[0015] The traditional circuit design only places a fuse at the AC input side, and the pressure sensitive resistor has no over-temperature protection, when there is an abnormally high voltage input from the outside, the input large capacitor explosion-proof valve is easily opened, which can cause the shell to melt and thus cause great safety hazards to consumers.

[0016] In use, the circuit design of the double insurance and the temperature fuse can form multiple circuit protection, effectively avoid the risk of plastic shell melting caused by device short circuit, and improve the product reliability.

[0017] When the top explosion-proof valve of the input electrolytic capacitor CX1 is opened and electrolyte is sprayed, the electrolyte can be absorbed by the electrolyte absorption structure, reducing the electrolyte falling on the circuit to cause short circuit heating or fire to cause the shell to melt.

[0018] Additional aspects and advantages of the application will be described in part below, some will become apparent from the following description, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below only constitute some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0020] Figure 1 is a circuit schematic diagram of the present application; Figure 2 is a structural schematic diagram of the power adapter shell of the present application; Figure 3 is a structural schematic diagram of the circuit board inside the lower shell of the present application, without setting insulation glue and absorbing cotton; Figure 4 is a structural sectional view of the power adapter shell of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] Please refer to Figures 1-4 , an abnormal external extra-high voltage input anti-fusing shell circuit, comprising a power adapter shell 1, a circuit board 2 is arranged in the power adapter shell 1, and an input rectification and filtering unit is arranged on the circuit board 2.

[0023] The input rectification and filtering unit comprises a fuse F1, a fuse F2, a temperature fuse TF1, a lightning arrester device pressure sensitive resistor MOV1, and an input electrolytic capacitor CX1.

[0024] The AC input side is composed of a double-fuse circuit of the fuse F1 and the fuse F2.

[0025] The temperature fuse TF1 and the pressure sensitive resistor MOV1 constitute a series circuit, and the temperature fuse TF1 and the pressure sensitive resistor MOV1 are in close contact, and a socket 4 is used to keep the temperature fuse TF1 and the pressure sensitive resistor MOV1 in close contact in the power adapter shell 1.

[0026] An electrolyte absorbing structure is arranged in the power adapter shell 1, and the electrolyte absorbing structure is used to absorb the electrolyte when the electrolyte is sprayed out after the explosion-proof valve on the top of the input electrolytic capacitor CX1 is opened.

[0027] The first-stage fuse F1 can withstand large surge lightning currents, while the second-stage fuse F2 can provide timely protection in case of abnormalities in the downstream circuit.

[0028] Traditional circuit designs simply place a fuse on the AC input side, with no over-temperature protection for the varistor. When there is an abnormally high voltage input from the outside, the explosion-proof valve of the large input capacitor can easily open, causing the casing to melt and break down, thus posing a great safety hazard to consumers.

[0029] In use, this invention forms multiple circuit protections through a circuit design with double insurance and the introduction of a temperature fuse, which can effectively avoid the risk of the plastic shell melting due to short circuit of the device and improve product reliability.

[0030] When the explosion-proof valve on the top of the input electrolytic capacitor CX1 is opened and the electrolyte is sprayed out, the electrolyte can also be absorbed by the electrolyte absorption structure, reducing the possibility of short circuits, overheating, or fires caused by electrolyte falling onto the circuit, which could lead to the casing melting and breaking down.

[0031] In some embodiments, the electrolyte absorption structure includes an absorption foam 3 disposed on top of the input electrolytic capacitor CX1, which absorbs the electrolyte of the electrolytic capacitor after the explosion-proof valve on the top of the electrolytic capacitor CX1 is opened, thereby reducing the amount of electrolyte overflow.

[0032] In some embodiments, the absorbent foam 3 has a bottom surface facing the top of the input electrolytic capacitor CX1, a top surface facing away from the top of the input electrolytic capacitor CX1, and a plurality of side surfaces located between the top surface and the bottom surface.

[0033] A liquid-proof layer is provided on the top surface and the side surface of the absorbent foam 3. The liquid-proof layer is used to prevent the electrolyte from seeping out from the corresponding absorbent foam surface.

[0034] The bottom surface of the absorbent foam 3 has an absorption area directly opposite the top of the input electrolytic capacitor CX1, and a redundant area outside the absorption area. A liquid-insulating layer is provided on the redundant area.

[0035] When the explosion-proof valve on the top of the input electrolytic capacitor CX1 is opened and the electrolyte is sprayed out, the electrolyte is sprayed into the absorption area and is quickly absorbed by the absorption foam 3. The design of the redundant area allows the absorption foam 3 to absorb a large amount of electrolyte, and it is not easy for leakage or dripping to occur on the bottom surface of the absorption foam 3.

[0036] In some embodiments, the absorbent area of ​​the absorbent foam 3 has an upwardly recessed spray chamber 301, and the top of the input electrolytic capacitor CX1 is positioned to enter the spray chamber 301. When the explosion-proof valve on the top of the input electrolytic capacitor CX1 opens and sprays out electrolyte, the absorbent foam 3 can effectively block the sprayed electrolyte, preventing it from being sprayed directly onto the wiring inside the power adapter.

[0037] Preferably, the sidewall of the injection chamber 301 contacts the side of the top of the input electrolytic capacitor CX1, so that the injection chamber 301 is fitted tightly onto the top of the input electrolytic capacitor CX1.

[0038] The absorbent foam 3 can simultaneously absorb the electrolyte flowing down from the side wall of the input electrolytic capacitor CX1, and in daily use, the absorbent foam 3 can be positioned on the top of the input electrolytic capacitor CX1.

[0039] Furthermore, when the electrolyte is sprayed out, the absorbent foam 3 on top of the input electrolytic capacitor CX1 also forms a sound-absorbing structure to reduce the noise heard from the outside during spraying.

[0040] In some embodiments, absorbent sponges may be used instead of absorbent foam.

[0041] In some embodiments, the L-side and N-side of the AC input side are covered with insulating adhesive to prevent leakage and short circuit between the L-line and N-line after electrolyte is ejected. By combining the above design, a multi-layered protection system is formed, which provides circuit protection before the input electrolytic capacitor is sprayed with electrolyte, electrolyte absorption protection during the spraying process, and short-circuit protection after the electrolyte is sprayed. This system makes the product less likely to ignite the circuit board and casing due to electrolyte, thus making it safer to use.

[0042] In some embodiments, the thermal fuse TF1 and the varistor MOV1 are located close to the L side of the AC input side and the N side of the AC input side.

[0043] When insulating adhesive is applied to the L side and N side of the AC input side, the insulating adhesive simultaneously fixes the sleeve 4 sleeved on the thermal fuse TF1 and the varistor MOV1, and forms a shape and fastening around the sleeve 4.

[0044] The insulating adhesive is, for example, curable silicone. The sleeve 4 is, for example, a heat-shrink tubing, which, when heated, allows the thermal fuse TF1 and the varistor MOV1 to be tightly fitted and kept in close contact.

[0045] The heat-shrinking and tightening effect of the sleeve 4 provides a good foundation for the application of insulating adhesive (that is, it can better ensure that the thermal fuse TF1 and the varistor MOV1 are in a tight fit). After the insulating adhesive is applied and cured, the sleeve 4 simultaneously tightens the thermal fuse TF1 and the varistor MOV1 together. Under the tightness of the insulating adhesive, the sleeve can maintain a tight fit and is less likely to loosen due to aging of the sleeve.

[0046] In some embodiments, the power adapter housing 1 includes an upper housing 5 and a lower housing 6.

[0047] After the lower edge of the upper shell 5 is closed with the upper edge of the lower shell 6, the power adapter housing 1 is obtained, forming an installation space inside the power adapter housing.

[0048] The portion of the lower edge of the upper shell 5 near the inner side extends downward to form a first connecting frame 501 corresponding to the inner side of the upper edge of the lower shell.

[0049] The upper edge of the upper shell 5 is recessed upward near the first connecting frame to form a connecting groove 502, and the upper edge of the lower shell 6 extends upward near the inner side to form a second connecting frame 601 that mates with the connecting groove 502.

[0050] When the upper shell 5 and the lower shell 6 are joined, the second connecting frame 601 is inserted into the connecting groove 502, and the first connecting frame 601 is inserted into the lower shell 6 along the inner side of the upper edge. Then, ultrasonic welding is used to weld the first connecting frame 501 to the inner side of the upper edge of the lower shell 6, and to weld the second connecting frame 601 to the inner wall of the connecting groove 502, forming a double-stop connection structure. The connection strength between the upper and lower shells is good, and it can effectively resist the power adapter housing being blown open after the input electrolytic capacitor explosion-proof valve is opened.

[0051] In some embodiments, the input rectifier filter unit is used to rectify the input AC power into DC power, and at the same time shape the sawtooth wave current at the back end into a current waveform that is close to a sinusoidal envelope.

[0052] The input rectifier and filter unit also includes a common-mode inductor LF1, a rectifier bridge BD1, and a thermistor NTC1.

[0053] One end of fuse F1 is connected to the L side of the AC input side, and the other end of fuse F1 is connected to one end of thermal fuse TF1. The other end of thermal fuse TF1 is connected to one end of fuse F2, and the other end of fuse F2 is connected to one end of the first winding LF1B of common mode inductor LF1. The other end of the first winding LF1B of common mode inductor LF1 is connected to the first input terminal of rectifier bridge BD1.

[0054] One end of the varistor MOV1 is connected to the common voltage point of the thermal fuse TF1 and the fuse F2. The other end of the varistor MOV1 is connected to the N side of the AC input side. One end of the thermistor NTC1 is connected to the other end of the varistor MOV1. The other end of the thermistor NTC1 is connected to one end of the second winding LF1A of the common mode inductor LF1.

[0055] The other end of the second winding LF1A of the common mode inductor LF1 is connected to the second input terminal of the rectifier bridge BD1.

[0056] One end of the input electrolytic capacitor CX1 is connected to the other end of the fuse F2, and the other end of the input electrolytic capacitor CX1 is connected to the other end of the thermistor NTC1.

[0057] In some embodiments, this abnormal external ultra-high voltage input anti-melt housing circuit also includes The input filter unit is used for smoothing filtering after rectification. The input filter unit includes filter capacitor C1, absorption circuit resistors and capacitors R6 and R7, absorption capacitors C2 and C2A, and damping diode D1; Transformer T1; The input detection control unit is used to detect the input voltage waveform to determine the output voltage and as a reference for frequency detection. It includes control IC U1, VCC rectifier diode D2, current-limiting resistor R10, and filter capacitors C3 and C4. The output filter unit provides a stable DC level to the subsequent circuit through the synchronous rectifier IC U2. It includes electrolytic capacitor C14, and a secondary absorption circuit composed of capacitors C10 and C11, resistors R20 and R21.

[0058] In some embodiments, the input rectifier filter unit further includes a fast start-up circuit composed of resistors R1, R1A, R2, R2A, R3, and R4.

[0059] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An abnormal external ultra-high voltage input anti-melt casing circuit, characterized in that, It includes a power adapter housing, inside which is a circuit board, and on which an input rectifier and filter unit is installed; The input rectifier and filter unit includes fuse F1, fuse F2, thermal fuse TF1, surge protector varistor MOV1, and input electrolytic capacitor CX1; The AC input side is equipped with a double-protection circuit consisting of fuses F1 and F2; The thermal fuse TF1 and the varistor MOV1 form a series circuit, and the thermal fuse TF1 and the varistor MOV1 are in close contact. A sleeve is used to keep the thermal fuse TF1 and the varistor MOV1 in close contact inside the power adapter housing. The power adapter housing is equipped with an electrolyte absorption structure, which is used to absorb the electrolyte when the explosion-proof valve on the top of the input electrolytic capacitor CX1 is opened and electrolyte is sprayed out.

2. The abnormal external ultra-high voltage input anti-melt casing circuit according to claim 1, characterized in that, The electrolyte absorption structure includes absorbent foam or absorbent sponge disposed on top of the input electrolytic capacitor CX1.

3. The abnormal external ultra-high voltage input anti-melt casing circuit according to claim 1, characterized in that, The L side of the AC input side and the N side of the AC input side are covered with insulating adhesive.

4. The abnormal external ultra-high voltage input anti-melt casing circuit according to claim 3, characterized in that, The thermal fuse TF1 and the varistor MOV1 are located close to the L side of the AC input side and the N side of the AC input side; When insulating adhesive is applied to the L side and N side of the AC input side, the insulating adhesive simultaneously fixes the sleeves fitted on the thermal fuse TF1 and the varistor MOV1, and forms a shape-fixing and tightening effect on the outer periphery of the sleeves.

5. The abnormal external ultra-high voltage input anti-melt casing circuit according to claim 1, characterized in that, The power adapter housing consists of an upper shell and a lower shell; The lower edge of the upper shell and the upper edge of the lower shell are fitted together to form the power adapter housing, creating an installation space inside the power adapter housing. The portion of the lower edge of the upper shell near the inner side extends downward to form a first connecting frame corresponding to the inner side of the upper edge of the lower shell; The upper edge of the upper shell near the first connecting frame is recessed upward to form a connecting groove, and the upper edge of the lower shell near the inner side extends upward to form a second connecting frame that mates with the connecting groove. When the upper shell and the lower shell are joined together, the second connecting frame is inserted into the connecting groove, and the first connecting frame is inserted into the lower shell along the inner side of the upper edge of the lower shell. Then, ultrasonic welding is used to weld the first connecting frame to the inner side of the upper edge of the lower shell, and to weld the second connecting frame to the inner wall of the connecting groove, forming a double-stop connection structure.

6. The abnormal external ultra-high voltage input anti-melt casing circuit according to claim 1, characterized in that, The input rectifier and filter unit also includes a common-mode inductor LF1, a rectifier bridge BD1, and a thermistor NTC1; One end of fuse F1 is connected to the L side of the AC input side, and the other end of fuse F1 is connected to one end of thermal fuse TF1. The other end of thermal fuse TF1 is connected to one end of fuse F2, and the other end of fuse F2 is connected to one end of the first winding LF1B of common mode inductor LF1. The other end of the first winding LF1B of common mode inductor LF1 is connected to the first input terminal of rectifier bridge BD1. One end of the varistor MOV1 is connected to the common voltage point of thermal fuses TF1 and F2, and the other end of the varistor MOV1 is connected to the N side of the AC input. One end of the thermistor NTC1 is connected to the other end of the varistor MOV1, and the other end of the thermistor NTC1 is connected to one end of the second winding LF1A of the common mode inductor LF1. The other end of the second winding LF1A of the common-mode inductor LF1 is connected to the second input terminal of the rectifier bridge BD1. One end of the input electrolytic capacitor CX1 is connected to the other end of the fuse F2, and the other end of the input electrolytic capacitor CX1 is connected to the other end of the thermistor NTC1.

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