CN202282601U - Protection circuit combining high-polymer phenylthiocarbamide (PTC) thermistor and piezoresistor - Google Patents
Protection circuit combining high-polymer phenylthiocarbamide (PTC) thermistor and piezoresistor Download PDFInfo
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- CN202282601U CN202282601U CN2011204732180U CN201120473218U CN202282601U CN 202282601 U CN202282601 U CN 202282601U CN 2011204732180 U CN2011204732180 U CN 2011204732180U CN 201120473218 U CN201120473218 U CN 201120473218U CN 202282601 U CN202282601 U CN 202282601U
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- piezoresistor
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Abstract
A protection circuit combining a high-polymer phenylthiocarbamide (PTC) thermistor and a piezoresistor is composed of a power supply, a resettable fuse, the piezoresistor and a load. The piezoresistor is in parallel connection with the load and then in series connection with the resettable fuse. The scheme is adopted, and the protection circuit can not only protect safety of the load under transient overvoltage, but also can protect the safety of the load under the condition of long overvoltage, and can be widely applied to various alternating-current and direct-current circuits.
Description
Affiliated technical field
The utility model relates to a kind of protective circuit, particularly uses the protective circuit of macromolecular PTC thermistor and piezo-resistance combination.
Background technology
At present, use macromolecular PTC thermistor to be used for the overcurrent protection of multiple circuit, macromolecular PTC thermistor is self-healing fuse again, by through the polymer resin of special processing and the conducting particles inside being distributed in form.Polymer resin closely is strapped in conducting particles outside the crystalloid structure under normal operation; Constitute chain conduction electric pathway; The self-healing fuse of this moment is a low resistive state, and the heat energy that electric current produced of the self-healing fuse of flowing through on the circuit is little, can not change crystal structure.When circuit was short-circuited or transship, the heat that the big electric current of the self-healing fuse of flowing through produces melted polymer resin, and volume increases rapidly, forms high-impedance state, and operating current reduces rapidly, thereby circuit is limited and protects.After fault was got rid of, self-healing fuse is crystallisation by cooling again, volume contraction; Conducting particles forms conductive path again, and resettable fuse reverts to low resistive state, thereby accomplishes the protection to circuit; Need not artificially change, the action of self-healing fuse needs certain hour, but macromolecular PTC thermistor is realized high resistance and protective circuit by heating; Some circuit causes big electric current to raising because of voltage, and this electric current does not reach the operating current of macromolecular PTC thermistor again, and the circuit long period works in than current state; Will cause to a certain degree circuit and damage, so it uses protective effect limited separately; Piezo-resistance is usually used in overvoltage protection, and resistance value becomes with voltage in certain current/voltage scope, or says the resistance device of " resistance value is to voltage-sensitive ".English name is abbreviated as " VDR ", and the resistive element material of varistor is a semiconductor, so it is a kind of semiconductor resistor; The maximum characteristics of piezo-resistance are the voltage above being added in it when being lower than its threshold values, and the electric current that flows through it is minimum, is equivalent to one and closes dead valve; When voltage surpassed threshold values, the electric current that flows through it increased sharply, and is equivalent to valve open; Utilize this function, can suppress the frequent abnormal overvoltage that occurs in the circuit, protective circuit is avoided superpotential infringement; Piezo-resistance is widely used in protective circuit, but when using piezo-resistance as protective circuit separately, when overvoltage continues; Will damage piezo-resistance, piezo-resistance does not shield to circuit after damaging.
The utility model content
Cause big electric current at some circuit to raising in order to overcome existing macromolecular PTC thermistor because of voltage; This electric current does not reach the operating current of macromolecular PTC thermistor again; The circuit long period works in than current state, in the time of will causing to a certain degree damage and use piezo-resistance as protective circuit separately circuit, when overvoltage continues; Will damage piezo-resistance; After piezo-resistance was damaged, to the shortcoming that circuit does not shield, the utility model was used in combination macromolecular PTC thermistor and piezo-resistance; The effective safety of protective circuit, its good effect is: the damage to circuit shields to big electric current of the long period that possibly occur and the overvoltage of long period.
The utility model solves the technical scheme that its technical problem adopted:
The protective circuit of a kind of macromolecular PTC thermistor of the utility model and piezo-resistance combination; Form by power supply, resettable fuse, piezo-resistance, load; Resettable fuse one termination power; The other end is connected with load with piezo-resistance, adopts the circuit structure of connecting with resettable fuse again after piezo-resistance and the load parallel connection.
The technical scheme that the utility model adopts will conjunction with figs. elaborate in specific embodiments.
Description of drawings
Below in conjunction with accompanying drawing and embodiment the utility model is further specified.
Fig. 1 is the utility model circuit diagram.
1. power supplys among the figure, 2. resettable fuse, 3. piezo-resistance, 4. load.
Embodiment
In Fig. 1, we are that example further specifies the utility model with the protective circuit of implementing the combination of a kind of macromolecular PTC thermistor and piezo-resistance:
Fig. 1 is the utility model circuit diagram, and in Fig. 1, power supply 1 can be a DC power supply, also can be AC power; What use among the figure is AC power, and resettable fuse 2 adopts macromolecular PTC thermistors, connects with resettable fuse 2 after piezo-resistance 3 and load 4 parallel connections, when overvoltage appears suddenly in power supply 1 again; When being higher than the pressure sensitive voltage of piezo-resistance 3, the electric current that flows through it increases sharply, if transient overvoltage; Piezo-resistance 3 has just directly been protected the safety of load 4, but overvoltage uses piezo-resistance 3 to be used as protection component separately when lasting; Piezo-resistance possibly burnt, and cooperates with resettable fuse 2, and the overvoltage that continues makes piezo-resistance big electric current occur; This electric current makes resettable fuse 2 actions, cuts off the electricity supply, and has protected the safety of load 4.
In the specific implementation, the parameter of resettable fuse 2, piezo-resistance 3 can be confirmed according to physical circuit.
Claims (1)
1. the protective circuit of macromolecular PTC thermistor and piezo-resistance combination; Form by power supply (1), resettable fuse (2), piezo-resistance (3), load (4), it is characterized in that: connect with resettable fuse (2) again after piezo-resistance (3) and load (4) parallel connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204732180U CN202282601U (en) | 2011-11-12 | 2011-11-12 | Protection circuit combining high-polymer phenylthiocarbamide (PTC) thermistor and piezoresistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204732180U CN202282601U (en) | 2011-11-12 | 2011-11-12 | Protection circuit combining high-polymer phenylthiocarbamide (PTC) thermistor and piezoresistor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202282601U true CN202282601U (en) | 2012-06-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011204732180U Expired - Fee Related CN202282601U (en) | 2011-11-12 | 2011-11-12 | Protection circuit combining high-polymer phenylthiocarbamide (PTC) thermistor and piezoresistor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202282601U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103457251A (en) * | 2013-08-30 | 2013-12-18 | 武汉联创恒业科技有限公司 | Protective circuit based on PTC thermistor |
| CN106954314A (en) * | 2017-05-05 | 2017-07-14 | 电子科技大学 | A kind of constant current driver circuit for LED with dimming function |
| CN106973461A (en) * | 2017-05-05 | 2017-07-21 | 电子科技大学 | A kind of LED drive circuit |
| CN107027220A (en) * | 2017-05-05 | 2017-08-08 | 电子科技大学 | A kind of Dimmable LED drive circuit |
| CN107094330A (en) * | 2017-05-05 | 2017-08-25 | 电子科技大学 | A kind of LED drive circuit with dimming function |
| CN109217238A (en) * | 2018-11-16 | 2019-01-15 | 深圳市槟城电子有限公司 | A kind of protection circuit and electronic equipment |
-
2011
- 2011-11-12 CN CN2011204732180U patent/CN202282601U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103457251A (en) * | 2013-08-30 | 2013-12-18 | 武汉联创恒业科技有限公司 | Protective circuit based on PTC thermistor |
| CN106954314A (en) * | 2017-05-05 | 2017-07-14 | 电子科技大学 | A kind of constant current driver circuit for LED with dimming function |
| CN106973461A (en) * | 2017-05-05 | 2017-07-21 | 电子科技大学 | A kind of LED drive circuit |
| CN107027220A (en) * | 2017-05-05 | 2017-08-08 | 电子科技大学 | A kind of Dimmable LED drive circuit |
| CN107094330A (en) * | 2017-05-05 | 2017-08-25 | 电子科技大学 | A kind of LED drive circuit with dimming function |
| CN109217238A (en) * | 2018-11-16 | 2019-01-15 | 深圳市槟城电子有限公司 | A kind of protection circuit and electronic equipment |
| CN109217238B (en) * | 2018-11-16 | 2024-04-12 | 深圳市槟城电子股份有限公司 | Protection circuit and electronic equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120620 Termination date: 20121112 |