CN201813138U - Over-current protection circuit - Google Patents
Over-current protection circuit Download PDFInfo
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- CN201813138U CN201813138U CN2010205548113U CN201020554811U CN201813138U CN 201813138 U CN201813138 U CN 201813138U CN 2010205548113 U CN2010205548113 U CN 2010205548113U CN 201020554811 U CN201020554811 U CN 201020554811U CN 201813138 U CN201813138 U CN 201813138U
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Abstract
The utility model relates to the field of an electronic circuit, in particular to an over-current protection circuit. An alternating-current live wire is connected with an over-current transformer, the output of the over-current transformer is connected with a first input end of a comparator after being connected with a rectification unit and a time delay unit, the alternating-current live wire and an alternating-current zero wire are connected with a trip and a rectification bridge unit which comprises four diodes, the output end and the rectification ground end of the rectification bridge unit are connected with a silicon controlled rectifier and a voltage division unit which comprises resistors in series, the middle ends of the resistors in series are connected with a second input end of the comparator and are also connected with a voltage stabilizing diode and the rectification ground end of the rectification bridge unit, and the output end of the comparator is connected with a resistor, a voltage stabilizing diode, a polar diode and the control electrode of the silicon controlled rectifier in series. The over-current protection circuit with the rectification bridge unit, the resistor type voltage division unit, an operational amplification and comparison circuit, the silicon controlled rectifier and the strip can avoid electrical hazards.
Description
Technical field
The utility model relates to electronic circuit field, relates in particular to the current foldback circuit of the load of electric main driving.
Background technology
Various electric appliance loads (as refrigerator, television set, air conditioner, computer, hair dryer or the like) by electric main driving work are to be inseparable with people's life.But at the electric appliance load incoming end, only provide access interface, and lack necessary electic protection, have potential safety hazard for electric appliance load as switch on wall, power supply adaptor or socket etc.If when running into short circuit, electric leakage, overcurrent, ground wire electrification or ground wire and disconnecting, damage load easily and the user caused personal injury, also cause electrical fire easily, cause any property loss.
The utility model content
Therefore,, the utility model proposes a kind of rational and effective current foldback circuit at the problems referred to above, be arranged at the load incoming end before, be used to protect load, prevent that over-current phenomenon avoidance from taking place, and can avoid electric hidden danger.
The utility model adopts following technical scheme:
A kind of current foldback circuit; specifically: the live wire of alternating current connects one and crosses current transformer; this crosses behind rectification unit that current transformer output connects and the delay unit first input end to a comparator; the rectifying bridge type unit that the live wire of alternating current and zero line insert a release and be made up of 4 diodes; the partial pressure unit that the output of this rectifying bridge type unit and rectification ground termination are gone into a controllable silicon and be made up of the resistance of series connection; the intermediate ends of the resistance of series connection is connected to second input of a comparator; the intermediate ends of resistance of series connection connects the rectification ground end of a voltage stabilizing didoe to the rectifying bridge type unit, the output of the described comparator resistance of connecting; one voltage stabilizing didoe; behind the one polarity diode to the silicon controlled control utmost point.
Further, the intermediate ends of the resistance of described series connection also connects the rectification ground end of a filter capacitor to the rectifying bridge type unit.
Further, described rectification unit is the diode rectifier circuit unit.
Further, described delay unit is the RC time delay circuit unit.
Further, also connect a piezo-resistance between described live wire and the zero line.
Further, also connect a power supply indicating member of forming by diode in series, current-limiting resistance, light-emitting diode between described live wire and the zero line.
The utility model adopts as above technical scheme; by crossing the current foldback circuit that current transformer, rectifying bridge type unit, electric resistance partial pressure unit, amplifier comparison circuit and controllable silicon constitute; electric current to alternating current carries out monitoring and protection; when over-current phenomenon avoidance appears in the load incoming end; disconnect the alternating current input channel by trip coil control release; avoid electric hidden danger, ensured the person and property safety.
Description of drawings
Fig. 1 is circuit theory diagrams of the present utility model.
Embodiment
Now with embodiment the utility model is further specified in conjunction with the accompanying drawings.
Consult shown in Figure 1; the current foldback circuit of present embodiment; specifically: the live wire L of alternating current connects one and crosses current transformer ZCT1; this crosses behind rectification unit that current transformer ZCT1 output connects and the delay unit first input end to a comparator IC1; the rectifying bridge type cells D B1 that the live wire L of alternating current and zero line N insert a release TK1 and be made up of 4 diodes; the output of this rectifying bridge type cells D B1 and rectification ground termination is gone into a controllable silicon SCR 1 and by the resistance R 2 of series connection; R3; R7; the partial pressure unit that R8 forms; the resistance R 7 of series connection; the intermediate ends of R8 is connected to second input of a comparator IC1; the resistance R 2 of series connection; the intermediate ends of R3 connects a voltage stabilizing didoe D9 to the rectification of rectifying bridge type cells D B1 ground end, the output of the described comparator IC1 resistance R 9 of connecting; one voltage stabilizing didoe D10; behind the one polarity diode D11 to the control utmost point of controllable silicon SCR 1.
Preferably, the resistance R 2 of described series connection, the intermediate ends of R3 also connect the rectification ground end of a filter capacitor C4 to rectifying bridge type cells D B1, can be used for filtering noise jamming composition.
Preferably, described rectification unit is the diode rectifier circuit unit.Can filtering cross the clutter composition of current transformer ZCT1 output by this rectification unit, prevent to disturb, obtains more reliable and more stable overcurrent relatively terminal voltage import.
Preferably, described delay unit is the RC time delay circuit unit.Can regulate the overcurrent delay time by the RC span, time-delay is the inverse time lag, prevents at the moment of translator startup, release false tripping.
Preferably, also connect a piezo-resistance MOV1 between described live wire L and the zero line N, be used to avoid the surge voltage of live wire L and zero line N, avoid damaging load because of thunderbolt.
Preferably, also connect a power supply indicating member of forming by diode in series D1, current-limiting resistance R1, light-emitting diode D2 between described live wire L and the zero line N, be used to indicate load to insert the power supply operate as normal and use.
Current foldback circuit of the present utility model is normal at the protected circuit working of load, and the current foldback circuit normal power supply takes place in the absence of overcurrent.When load generation overcurrent; cross high voltage signal of current transformer ZCT1 output; by comparing with the reference voltage of comparator IC1 second input behind rectification rectification unit and the delay unit; if generation over-current phenomenon avoidance; then comparator IC1 triggers controllable silicon SCR 1 conducting by relatively back output one voltage signal; make the coil that is connected on the release between live wire L and the controllable silicon SCR 1 have big electric current to flow through; iron core pulling dropout plate in the coil of release TK1; make pull bar break away from the dropout plate; moving contact leaves fixed contact; this control release TK1 is cut off the electricity supply, avoided casualties, reach the purpose of overcurrent protection.
Although specifically show and introduced the utility model in conjunction with preferred embodiment; but the those skilled in the art should be understood that; in the spirit and scope of the present utility model that do not break away from appended claims and limited; can make various variations to the utility model in the form and details, be protection range of the present utility model.
Claims (6)
1. current foldback circuit; it is characterized in that: the live wire of alternating current (L) connects one and crosses current transformer (ZCT1); this crosses behind rectification unit that current transformer (ZCT1) output connects and the delay unit first input end to a comparator (IC1); the rectifying bridge type unit (DB1) that live wire of alternating current (L) and zero line (N) insert a release (TK1) and be made up of 4 diodes; the output of this rectifying bridge type unit (DB1) and rectification ground termination is gone into a controllable silicon (SCR1) and by the resistance (R2 of series connection; R3; R7; R8) partial pressure unit of Zu Chenging; resistance (the R7 of series connection; R8) intermediate ends is connected to second input of a comparator (IC1); resistance (the R2 of series connection; R3) intermediate ends connects a voltage stabilizing didoe (D9) to the rectification of rectifying bridge type unit (DB1) ground end, the output of described comparator (IC1) resistance (R9) of connecting; one voltage stabilizing didoe (D10); one polarity diode (D11) back is to the control utmost point of controllable silicon (SCR1).
2. current foldback circuit according to claim 1 is characterized in that: the intermediate ends of the resistance of described series connection (R2, R3) also connects the rectification ground end of a filter capacitor (C4) to rectifying bridge type unit (DB1).
3. current foldback circuit according to claim 1 is characterized in that: described rectification unit is the diode rectifier circuit unit.
4. current foldback circuit according to claim 1 is characterized in that: described delay unit is the RC time delay circuit unit.
5. current foldback circuit according to claim 1 is characterized in that: also connect a piezo-resistance (MOV1) between described live wire (L) and the zero line (N).
6. current foldback circuit according to claim 1 is characterized in that: also connect a power supply indicating member of being made up of diode in series (D1), current-limiting resistance (R1), light-emitting diode (D2) between described live wire (L) and the zero line (N).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205548113U CN201813138U (en) | 2010-09-29 | 2010-09-29 | Over-current protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205548113U CN201813138U (en) | 2010-09-29 | 2010-09-29 | Over-current protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201813138U true CN201813138U (en) | 2011-04-27 |
Family
ID=43896076
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010205548113U Expired - Lifetime CN201813138U (en) | 2010-09-29 | 2010-09-29 | Over-current protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201813138U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107819317A (en) * | 2016-09-13 | 2018-03-20 | 西门子公司 | Energy supply device |
-
2010
- 2010-09-29 CN CN2010205548113U patent/CN201813138U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107819317A (en) * | 2016-09-13 | 2018-03-20 | 西门子公司 | Energy supply device |
| US10680428B2 (en) | 2016-09-13 | 2020-06-09 | Siemens Aktiengesellschaft | Energy supply |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110427 |
|
| CX01 | Expiry of patent term |