CN202134911U - Detection protection circuit for preventing reverse connection of power supply fire wire and zero wire - Google Patents
Detection protection circuit for preventing reverse connection of power supply fire wire and zero wire Download PDFInfo
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- CN202134911U CN202134911U CN201120260640U CN201120260640U CN202134911U CN 202134911 U CN202134911 U CN 202134911U CN 201120260640 U CN201120260640 U CN 201120260640U CN 201120260640 U CN201120260640 U CN 201120260640U CN 202134911 U CN202134911 U CN 202134911U
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Abstract
The utility model provides a detection protection circuit for preventing the reverse connection of a power supply fire wire and zero wire. The detection protection circuit comprises a field effect transistor Q1, a triode Q2, a triode Q3 and a relay K1, wherein the grid electrode of the field effect transistor Q1 is taken as an induction fire wire and zero wire electric field radiation signal input end, the source electrode of the field effect transistor Q1 is grounded, the drain electrode of the field effect transistor Q1 is connected with the base electrode of the triode Q2 and is connected with a power supply via a resistor R2, the collector electrode of the triode Q2 is connected with the power supply via a resistor R3, the emitter electrode of the triode Q2 is connected with the base electrode of the triode Q3 via a resistor R4, the emitter electrode of the triode Q3 is grounded, one end of the relay K1 is connected with the collector electrode of the triode Q3, and the other end of the relay K1 is connected with the power supply. The detection protection circuit employs the difference in radiation of fire wire and zero wire electric fields and uses field effect transistor induction to drive the relay for controlling subsequent circuits, thereby effectively avoiding problems caused by the reverse connection of the power supply fire wire and zero wire, and the detection protection circuit is simple in design, convenient in usage, high in reliability and rapid in response, adds few parts to a conventional control circuit, and is low in cost and high in applicability.
Description
[technical field]
The utility model relates to a kind of circuit, refers in particular to a kind of detection protective circuit that prevents that the reversal connection of power supply fire zero line from using.
[background technology]
Along with expanding economy, household electrical appliance are also more and more universal.Yet in the installing and using of reality, the phenomenon of power supply fire zero line reversal connection is very general.In the thinking of most of people, fiery zero line reversal connection does not influence the normal use of household electrical appliance, so can correct.This is very wrong in fact.Say that from use angle fiery zero line reversal connection household electrical appliance still can operate as normal, but in fact says from security standpoint, has major safety risks.At first, household electrical appliance all are control, cut-out live wire from design principle, control circuit.If power firestreak, that zero line connects method is correct, then under holding state, the control circuit of household electrical appliance cuts off live wire, and its components and parts are not charged; If live wire, zero line reversal connection, then under holding state, what control circuit cut off is zero line, and components and parts are in the electriferous state of high potential all the time.Like this, under some special environment and situation, for example dirt accumulation is too much; And humid environment is big or electric power system when unusual, is prone to cause electrical distance, creepage distance to reduce, thereby produces arcing even short circuit sparking; Cause appliance fire, have serious potential safety hazard.
Therefore, provide a kind of can prevent the reversal connection of power supply fire zero line, to improve circuit safety performance detection protective circuit real in necessary.
[summary of the invention]
The purpose of the utility model is to provide a kind of detection protective circuit that can prevent the reversal connection of power supply fire zero line.
For realizing the utility model purpose, following technical scheme is provided:
The utility model provides a kind of detection protective circuit that prevents the reversal connection of power supply fire zero line; It comprises FET Q1, triode Q2, triode Q3 and relay K 1; The grid of this FET Q1 is as the fiery zero line electric field radiation signal input part of induction; The source ground of this FET Q1, drain electrode connects the base stage of triode Q2, and connects power supply through resistance R 2; The collector electrode of this triode Q2 connects power supply through resistance R 3, and emitter connects the base stage of triode Q3 through resistance R 4; The grounded emitter of this triode Q3; The collector electrode of this relay K 1 one termination triode Q3, another termination power.
As long as there is alternating voltage where, electric field radiation is just arranged.In fact; Under identical test condition; The electric field radiation signal of live wire is higher than the electric field radiation signal of zero line, and the technical scheme of the utility model is to utilize the difference of fiery zero line electric field radiation, through the electric field radiation signal of FET induction power supply fire zero line; Detect and judge fiery zero line, drive relay control subsequent conditioning circuit.Utilize this electric field radiation signal of grid induction of FET, strong and weak different according to induced signal, the source electrode of FET and drain electrode can present the characteristic of a kind of saturation conduction and pinch-off current, and then drive relay control subsequent conditioning circuit.
Distance through adjustment FET Q1 and live wire; Make FET Q1 sense the enough electric field radiation signals of power firestreak, drain electrode output signal after Q1 amplifies, Q2 progressively amplifies through triode; Export the base stage of Q3 again to through resistance R 4 by the Q2 emitter; Q3 gets into the saturation conduction state rapidly, and this moment, relay coil constituted current path, drives relay K 1 control subsequent conditioning circuit.When the reversal connection of power supply fire zero line; What then FET Q1 sensed is the more weak electric field radiation signal of zero-power line, and Q3 does not have enough big signal to promote, can not conducting; Can't drive relay K 1 control subsequent conditioning circuit, and then realize preventing the defencive function of power supply fire zero line reversal connection.
Preferably, this detection protective circuit further comprises filter capacitor C1, and the positive pole of this filter capacitor C1 connects the emitter of this triode Q2, the minus earth of this filter capacitor C1.This filter capacitor C1 has the energy storage effect, has guaranteed the steady operation of triode Q3.
Preferably, the grid of this FET Q1 is through resistance R 1 ground connection.Can discharge the static of this FET Q1 grid like this, Q1 shields to this FET.
Preferably, this detection protective circuit further comprises diode D1, and this diode D1 is parallelly connected with relay K 1, and the anode of diode D1 connects the collector electrode of triode Q3, and the negative electrode of diode D1 connects power supply.The instantaneous pressure that this diode D1 and relay K 1 are parallelly connected can absorb the relay coil outage time.
The contrast prior art the utlity model has following advantage:
The detection protective circuit of the utility model is utilized the difference of fiery zero line electric field radiation; Respond to through FET and to drive relay control subsequent conditioning circuit; Effectively prevent the caused problem of power supply fire zero line reversal connection, its simplicity of design, easy to use, reliability is high, be quick on the draw, and the part that on original control circuit, increases is few; Cost is low, and applicability is strong.
[description of drawings]
Fig. 1 detects the embodiment circuit diagram of protective circuit for the utility model.
[embodiment]
See also Fig. 1; The utility model prevents the sketch map of the detection protective circuit of power supply fire zero line reversal connection; This circuit includes FET Q1, triode Q2, triode Q3, relay K 1, diode D1 and filter capacitor C1, and the grid of this FET Q1 is as the fiery zero line electric field radiation signal input part of induction, and distance is according to the practical application setting between itself and live wire; And the grid of this FET Q1 is through resistance R 1 ground connection; The source ground of this FET Q1, the drain electrode of this FET Q1 connects the base stage of triode Q2, and connects power supply through resistance R 2; The collector electrode of this triode Q2 connects power supply through resistance R 3; The emitter of this triode Q2 connects the base stage of triode Q3 through resistance R 4; And through filter capacitor C1 ground connection, the positive pole of this filter capacitor C1 connects the emitter of this triode Q2, the minus earth of this filter capacitor C1; The grounded emitter of this triode Q3; The collector electrode of this relay K 1 one termination triode Q3, another termination power; Relay K 1 is parallelly connected with diode D1, and the anode of diode D1 connects the collector electrode of triode Q3, and the negative electrode of diode D1 connects power supply.
Distance through adjustment FET Q1 and live wire; Make FET Q1 sense the enough electric field radiation signals of power firestreak, drain electrode output signal after Q1 amplifies, Q2 progressively amplifies through triode; Export the base stage of Q3 again to through resistance R 4 by the Q2 emitter; Q3 gets into the saturation conduction state rapidly, and this moment, relay coil constituted current path, drives relay K 1 control subsequent conditioning circuit.When the reversal connection of power supply fire zero line; What then FET Q1 sensed is the more weak electric field radiation signal of zero-power line, and Q3 does not have enough big signal to promote, can not conducting; Can't drive relay K 1 control subsequent conditioning circuit, and then realize preventing the defencive function of power supply fire zero line reversal connection.Wherein filter capacitor C1 has the energy storage effect, has guaranteed the steady operation of triode Q3; Resistance R 1 discharges the static of this FET Q1 grid, and Q1 shields to this FET; The instantaneous pressure that diode D1 and relay K 1 are parallelly connected can absorb the relay coil outage time.
The above is merely the preferred embodiment of the utility model, and the protection range of the utility model is not limited thereto, and anyly all belongs within the utility model protection range based on the equivalent transformation on the utility model technical scheme.
Claims (4)
1. detection protective circuit that prevents the reversal connection of power supply fire zero line; It is characterized in that; It comprises FET Q1, triode Q2, triode Q3 and relay K 1, and the grid of this FET Q1 is as the fiery zero line electric field radiation signal input part of induction, the source ground of this FET Q1; Drain electrode connects the base stage of triode Q2, and connects power supply through resistance R 2; The collector electrode of this triode Q2 connects power supply through resistance R 3, and emitter connects the base stage of triode Q3 through resistance R 4; The grounded emitter of this triode Q3; The collector electrode of this relay K 1 one termination triode Q3, another termination power.
2. the detection protective circuit that prevents the reversal connection of power supply fire zero line as claimed in claim 1 is characterized in that it further comprises filter capacitor C1, and the positive pole of this filter capacitor C1 connects the emitter of this triode Q2, the minus earth of this filter capacitor C1.
3. like claim
1The described detection protective circuit that prevents the reversal connection of power supply fire zero line is characterized in that the grid of this FET Q1 is through resistance R 1 ground connection.
4. like claim
1The described detection protective circuit that prevents the reversal connection of power supply fire zero line is characterized in that it further comprises diode D1, and this diode D1 is parallelly connected with relay K 1, and the anode of diode D1 connects the collector electrode of triode Q3, and the negative electrode of diode D1 connects power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120260640U CN202134911U (en) | 2011-07-22 | 2011-07-22 | Detection protection circuit for preventing reverse connection of power supply fire wire and zero wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120260640U CN202134911U (en) | 2011-07-22 | 2011-07-22 | Detection protection circuit for preventing reverse connection of power supply fire wire and zero wire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202134911U true CN202134911U (en) | 2012-02-01 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201120260640U Expired - Lifetime CN202134911U (en) | 2011-07-22 | 2011-07-22 | Detection protection circuit for preventing reverse connection of power supply fire wire and zero wire |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202134911U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103378593A (en) * | 2012-04-20 | 2013-10-30 | 海洋王（东莞）照明科技有限公司 | Electric supply zero fire wire identification circuit |
| WO2017107556A1 (en) * | 2015-12-25 | 2017-06-29 | 深圳长城开发科技股份有限公司 | Electricity meter and live wire detection circuit |
-
2011
- 2011-07-22 CN CN201120260640U patent/CN202134911U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103378593A (en) * | 2012-04-20 | 2013-10-30 | 海洋王（东莞）照明科技有限公司 | Electric supply zero fire wire identification circuit |
| WO2017107556A1 (en) * | 2015-12-25 | 2017-06-29 | 深圳长城开发科技股份有限公司 | Electricity meter and live wire detection circuit |
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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 | ||
| CX01 | Expiry of patent term |
Granted publication date: 20120201 |