CN208890346U - Leakage protection circuit - Google Patents
Leakage protection circuit Download PDFInfo
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- CN208890346U CN208890346U CN201821622914.1U CN201821622914U CN208890346U CN 208890346 U CN208890346 U CN 208890346U CN 201821622914 U CN201821622914 U CN 201821622914U CN 208890346 U CN208890346 U CN 208890346U
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Abstract
The utility model relates to electric leakage protection technology fields, especially disclose a kind of leakage protection circuit, including sample circuit, for the current signal in Acquisition Circuit, it further include sampled signal processing circuit, the sampled signal processing circuit includes two groups of differential amplifier circuits and one group of subtraction circuit, the sample circuit includes two groups of sampling resistors, the current difference at sampling resistor both ends forms sampled signal, two groups of sampled signals are connect with the input terminal of respective differential amplifier circuit, the output end of two groups of differential amplifier circuits is connect with the input terminal of subtraction circuit.Using above-mentioned design, a kind of leakage protection circuit that leakage current is acquired using resistance is provided.
Description
Technical field
The utility model relates to electric leakage protection technology field, especially a kind of leakage protection circuit.
Background technique
When manpower accidentally touches firewire or the load of electric leakage situation occurs, firewire, human body, the earth, between zero curve
As soon as just will form a circuit, electric current is had on the person and is passed through, when electric current is sufficiently large, it is possible to cause to endanger to human body
Evil.It is to prevent one of effective measures of accident of human electric shock, and prevent because of leakage that earth leakage protective device is set in low-voltage distribution system
Electricity causes one of electrical fire and the technical measures of electrical equipment damage accident.
Common earth leakage protective device has earth leakage protective device, breaker etc..In the prior art, when loading on-line operation,
It can whether have leak current fault in detection circuit by detecting element, such as mutual inductor, in concrete application, the fire of a certain phase line
Line, zero curve pass through the magnet ring of mutual inductor, constitute the primary coil of mutual inductor, the winding being wrapped on magnet ring constitutes mutual inductor
Second siding ring.If not leaking electricity generation, at this moment flow through firewire, zero curve current vector and be equal to zero, therefore in mutual inductance
Corresponding induced electromotive force will not be generated on the second siding ring of device.And in case of electric leakage, then the electric current of firewire, zero curve
Vector sum is not equal to zero, will make to generate induced electromotive force on the second siding ring of mutual inductor, and trigger executing agency, such as de-
Detain the power supply at device tripping disengagement failure.
But mutual inductor volume is larger, and it is also poor with the adaptability of other circuits, it is highly integrated not meet component instantly
Development prospect.
Summary of the invention
In order to overcome the deficiencies of the prior art, the utility model provides a kind of is acquired leakage current using resistance
Leakage protection circuit.
To achieve the goals above, the technical solution adopted in the utility model is: a kind of leakage protection circuit, including sampling
Circuit further includes sampled signal processing circuit for the current signal in Acquisition Circuit, and the sampled signal processing circuit includes
Two groups of differential amplifier circuits and one group of subtraction circuit, the sample circuit include two groups of sampling resistors, sampling resistor both ends
Current difference form sampled signal, two groups of sampled signals connect with the input terminal of respective differential amplifier circuit, and two groups are poor
The output end of amplifying circuit is divided to connect with the input terminal of subtraction circuit.
In above-mentioned technical proposal, sampled signal is acquired by sample circuit, is passing through differential amplifier circuit for sampled signal
It is output to after amplification in subtraction circuit, two-way is done into subtraction using signal, compares whether the numerical value after doing subtraction is 0, if
It is zero to illustrate leakproof, if not zero illustrates to leak electricity, realizes the detection of leakage current, effectively disconnection leakage current, be detached from mutual to electric current
Diversification detection is realized in the dependence of sensor, and the electric-leakage detection circuit integrated level is higher, and volume is smaller, more adaptable, before
Scape is more extensive.
As the further setting of the utility model, wherein one group of sampling resistor includes be connected in L phase line
One resistance and second resistance, another group of sampling resistor include the 3rd resistor being connected in N phase line and the 4th resistance, first resistor
With second resistance parallel connection, 3rd resistor and the 4th resistor coupled in parallel.
In above-mentioned technical proposal, sampling resistor is formed by multiple resistor coupled in parallel, and the number of resistance is more, and sampled signal is more steady
It is fixed, precision is improved, power is increased, when leakage current is excessive, sampling resistor damage is can avoid, improves safety coefficient.
It further include comparison circuit, the output end of subtraction circuit is compared with as the further setting of the utility model
The input terminal of circuit connects.
In above-mentioned technical proposal, for comparison circuit for judging whether route leaks electricity, circuit is simple, practical.
As the further setting of the utility model, the differential amplifier circuit includes the first amplifier, the 5th resistance, the
Six resistance, the 7th resistance, first capacitor and the second capacitor, wherein the 5th resistance and the 6th resistance are connected to the first amplifier
The 4th and third pin on, first and the 4th pin of the first amplifier are connected to after the 7th resistance and first capacitor are in parallel
On, the first lift piezoresistance and the second lift piezoresistance, the both ends of the first lift piezoresistance are connected in the second pin of the first amplifier
It is connected on second and third pin of the first amplifier, the second lift piezoresistance is connected with the first lift piezoresistance, and the second capacitor is simultaneously
It is associated on the first lift piezoresistance.
In above-mentioned technical proposal, the setting of the first lift piezoresistance and the second lift piezoresistance is the zero point in order to raise voltage,
Because input signal is alternating current, there are negative values, it is therefore necessary to raise voltage, are convenient for signal processing.
As the further setting of the utility model, the subtraction circuit includes the second amplifier, the 8th resistance, the
Nine resistance and the tenth resistance, wherein the 8th resistance be connected to a differential amplifier circuit output end and the second amplifier the 4th
On pin, the 9th resistance is connected on the output end of another differential amplifier circuit and the third pin of the second amplifier, and the tenth
Resistance is connected to the first and the 4th of the second amplifier on pin, and third lift piezoelectricity is connected in the second pin of the second amplifier
Resistance and the 4th lift piezoresistance, third lift piezoresistance both ends be connected on second and third pin, the 4th lift piezoresistance and
Third lifts piezoresistance series connection.
In above-mentioned technical proposal, the setting of third lift piezoresistance and the 4th lift piezoresistance is the zero point in order to raise voltage,
Because input signal is alternating current, there are negative values, it is therefore necessary to raise voltage, are convenient for signal processing.
As the further setting of the utility model, the comparison circuit includes comparator, eleventh resistor, the 12nd electricity
Resistance, thirteenth resistor and the 14th resistance, eleventh resistor are connected on the third pin of comparator, and twelfth resistor is connected to
On 4th pin of comparator, thirteenth resistor is connected on the 5th and the 4th pin of comparator, and the 14th resistance is connected to
On first and third pin of comparator, the 15th resistance and third capacitor are connected on the first pin of comparator.
The utility model is further described with reference to the accompanying drawing.
Detailed description of the invention
Attached drawing 1 is the utility model specific embodiment circuit diagram；
Attached drawing 2 is the circuit diagram that the utility model specific embodiment acquires signal processing circuit；
Attached drawing 3 is the circuit diagram of the utility model specific embodiment comparison circuit；
Attached drawing 4 is the utility model specific embodiment flow diagram.
Specific embodiment
Specific embodiment of the utility model is as shown in Figs 1-4, a kind of leakage protection circuit, including sample circuit 1, is used for
Current signal in Acquisition Circuit further includes sampled signal processing circuit 2, and the sampled signal processing circuit 2 includes two groups poor
Divide amplifying circuit 21 and one group of subtraction circuit 22, the sample circuit 1 includes two groups of sampling resistors 11,12, sampling resistor
11, the current difference at 12 both ends forms sampled signal, the input terminal of two groups of sampled signals and respective differential amplifier circuit 21
Connection, the output end of two groups of differential amplifier circuits 21 are connect with the input terminal of subtraction circuit 22.It is acquired by sample circuit 1
Sampled signal is output in subtraction circuit 22 after being amplified sampled signal by differential amplifier circuit 21, two-way is adopted
Subtraction is done with signal, compares whether the numerical value after doing subtraction is 0, illustrates leakproof if zero, if not zero illustrates to leak electricity, is realized
The detection of leakage current, effectively disconnection leakage current, are detached from the dependence to current transformer, realize diversification detection, the detection of electrical leakage
Circuit level is higher, and volume is smaller, more adaptable, and application prospect is more extensive.
Above-mentioned wherein one group of sampling resistor 11 includes the first resistor 111 and second resistance 112 being connected in L phase line, separately
One group of sampling resistor 12 includes the 3rd resistor 121 being connected in N phase line and the 4th resistance 122, first resistor 111 and the second electricity
Resistance 112 is in parallel, and 3rd resistor 121 and the 4th resistance 122 are in parallel.Sampling resistor 11,12 is formed by multiple resistor coupled in parallel, resistance
Number is more, and sampled signal is more stable, improves precision, increases power, when leakage current is excessive, can avoid sampling resistor 11,12
Damage improves safety coefficient.
It further include comparison circuit 3, the output end of subtraction circuit 22 is connect with the input terminal of comparison circuit 3.Compare electric
For judging whether route leaks electricity, circuit is simple, practical on road 3.
Above-mentioned differential amplifier circuit 21 includes the first amplifier 211, the 5th resistance 212, the 6th resistance 213, the 7th resistance
214, first capacitor 215 and the second capacitor 216, wherein the 5th resistance 212 and the 6th resistance 213 are connected to the first amplifier
On 211 the 4th and third pin, the first of the first amplifier 211 is connected to after 215 parallel connection of the 7th resistance 214 and first capacitor
On the 4th pin, the first lift piezoresistance 217 and the second lift piezoresistance 218 are connected in the second pin of the first amplifier 211,
First lift piezoresistance 217 both ends be connected on second and third pin of the first amplifier 211, second lift piezoresistance 218 with
First lift piezoresistance 217 is connected, and the second capacitor 216 is connected in parallel on the first lift piezoresistance 217.First lift piezoresistance 217 and second
The setting of lift piezoresistance 218 is zero point in order to raise voltage, because input signal is alternating current, there are negative value, it is therefore necessary to
Voltage is raised, signal processing is convenient for.
Above-mentioned subtraction circuit 22 includes the second amplifier 221, the 8th resistance 222, the 9th resistance 223 and the tenth resistance
224, wherein the 8th resistance 222 is connected to the output end an of differential amplifier circuit 21 and the 4th pin of the second amplifier 221
On, the 9th resistance 223 is connected on the output end of another differential amplifier circuit 21 and the third pin of the second amplifier 221,
Tenth resistance 224 is connected to the first and the 4th of the second amplifier 221 on pin, connects in the second pin of the second amplifier 221
It is connected to third lift piezoresistance 225 and the 4th lift piezoresistance 226, the both ends of third lift piezoresistance 225 are connected to second and the
On three pins, the 4th lift piezoresistance 226 and third lift piezoresistance 225 are connected.Third lifts piezoresistance 225 and the 4th lift piezoresistance
226 setting is the zero point in order to raise voltage, and because input signal is alternating current, there are negative values, it is therefore necessary to raise voltage,
Convenient for signal processing.
Above-mentioned comparison circuit 3 includes comparator 31, eleventh resistor 32, twelfth resistor 33, thirteenth resistor 34 and the
14 resistance 35, eleventh resistor 32 are connected on the third pin of comparator 31, and twelfth resistor 33 is connected to comparator 31
The 4th pin on, thirteenth resistor 34 is connected on the 5th and the 4th pin of comparator 31, and the 14th resistance 35 is connected to
On first and third pin of comparator 31, the 15th resistance 36 and third capacitor are connected on the first pin of comparator 31
37。
The utility model is not limited to above-mentioned specific embodiment, and persons skilled in the art are according to the utility model public affairs
The content opened can be implemented the utility model or all using the utility model using other a variety of specific embodiments
Design structure and thinking, do simple change or change, both fall within the protection scope of the utility model.
Claims (6)
1. a kind of leakage protection circuit, including sample circuit, for the current signal in Acquisition Circuit, it is characterised in that: also wrap
Sampled signal processing circuit is included, the sampled signal processing circuit includes two groups of differential amplifier circuits and one group of subtraction electricity
Road, the sample circuit include two groups of sampling resistors, and the current difference at sampling resistor both ends forms sampled signal, two groups of samplings
Signal is connect with the input terminal of respective differential amplifier circuit, output end and the subtraction circuit of two groups of differential amplifier circuits
Input terminal connection.
2. leakage protection circuit according to claim 1, it is characterised in that: wherein one group of sampling resistor includes connection
First resistor and second resistance in L phase line, another group of sampling resistor include the 3rd resistor being connected in N phase line and the 4th
Resistance, first resistor and second resistance are in parallel, 3rd resistor and the 4th resistor coupled in parallel.
3. leakage protection circuit according to claim 1 or 2, it is characterised in that: further include comparison circuit, subtraction electricity
The output end on road and the input terminal of comparison circuit connect.
4. leakage protection circuit according to claim 3, it is characterised in that: the differential amplifier circuit includes the first amplification
Device, the 5th resistance, the 6th resistance, the 7th resistance, first capacitor and the second capacitor, wherein the 5th resistance and the 6th resistance connect respectively
It connects on the 4th and third pin of the first amplifier, the of the first amplifier is connected to after the 7th resistance and first capacitor are in parallel
On one and the 4th pin, the first lift piezoresistance and the second lift piezoresistance, the first lift are connected in the second pin of the first amplifier
The both ends of piezoresistance are connected on second and third pin of the first amplifier, the second lift piezoresistance and the first lift piezoresistance string
Connection, the second capacitor are connected in parallel on the first lift piezoresistance.
5. leakage protection circuit according to claim 4, it is characterised in that: the subtraction circuit includes the second amplification
Device, the 8th resistance, the 9th resistance and the tenth resistance, wherein the 8th resistance is connected to the output end and an of differential amplifier circuit
On 4th pin of two amplifiers, the 9th resistance be connected to another differential amplifier circuit output end and the second amplifier
On three pins, the tenth resistance is connected to the first and the 4th of the second amplifier on pin, connects in the second pin of the second amplifier
It is connected to third lift piezoresistance and the 4th lift piezoresistance, the both ends of third lift piezoresistance are connected on second and third pin,
4th lift piezoresistance and third lift piezoresistance series connection.
6. leakage protection circuit according to claim 3, it is characterised in that: the comparison circuit includes comparator, the tenth
One resistance, twelfth resistor, thirteenth resistor and the 14th resistance, eleventh resistor are connected on the third pin of comparator,
Twelfth resistor is connected on the 4th pin of comparator, and thirteenth resistor is connected on the 5th and the 4th pin of comparator,
14th resistance is connected on first and third pin of comparator, be connected on the first pin of comparator the 15th resistance and
Third capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821622914.1U CN208890346U (en) | 2018-09-30 | 2018-09-30 | Leakage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821622914.1U CN208890346U (en) | 2018-09-30 | 2018-09-30 | Leakage protection circuit |
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| Publication Number | Publication Date |
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| CN208890346U true CN208890346U (en) | 2019-05-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821622914.1U Active CN208890346U (en) | 2018-09-30 | 2018-09-30 | Leakage protection circuit |
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| CN (1) | CN208890346U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109245040A (en) * | 2018-09-30 | 2019-01-18 | 德力西电气有限公司 | leakage protection circuit |
-
2018
- 2018-09-30 CN CN201821622914.1U patent/CN208890346U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109245040A (en) * | 2018-09-30 | 2019-01-18 | 德力西电气有限公司 | leakage protection circuit |
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