CN205792219U - A kind of dummy load circuit of power circuit - Google Patents
A kind of dummy load circuit of power circuit Download PDFInfo
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- CN205792219U CN205792219U CN201620563829.7U CN201620563829U CN205792219U CN 205792219 U CN205792219 U CN 205792219U CN 201620563829 U CN201620563829 U CN 201620563829U CN 205792219 U CN205792219 U CN 205792219U
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Abstract
The utility model discloses the dummy load circuit of a kind of power circuit, including current sampling circuit, comparison circuit, the first on-off circuit, second switch circuit, transistor and dummy resistance.Current sampling circuit is for gathering the output electric current of power circuit, and exports the sampled voltage corresponding to exporting electric current；The first input end of comparison circuit and the second input electrically connect with the outfan of current sampling circuit and the reference voltage corresponding to predetermined threshold value electric current respectively；The input of second switch circuit electrically connects with the outfan of comparison circuit and the outfan of the first on-off circuit respectively；Transistor control input electrically connect with the outfan of second switch circuit, the first end of transistor electrically connects with the outfan of power circuit, the second end of transistor connect with dummy resistance after ground connection.This utility model is it can be avoided that the power circuit that causes turns off because the output electric current of power circuit is too small by mistake, and simple in construction, precise control, flexibly.
Description
Technical field
This utility model relates to the dummy load circuit of a kind of power circuit.
Background technology
Dummy load circuit (dummyload) is usually used in power circuit.In the case of the output electric current of power circuit is relatively big
Dummy load circuit will not work, and when the output electric current of power circuit constantly reduces, little to when cannot detect, fictitious load is electric
Road can provide a small area analysis, and the testing circuit relevant to power circuit so can be made to have detected load current, it is thus possible to
Ensure that power circuit is properly functioning, will not quit work because testing circuit does not detect load current.Therefore fictitious load
The when of circuit work, power is the least, and loss is not the biggest.
Utility model content
Technical problem to be solved in the utility model is to provide the dummy load circuit of a kind of power circuit, and it can be kept away
Exempt from because the output electric current of power circuit is too small that the power circuit that causes turns off by mistake, and simple in construction, precise control, flexibly.
For solving above-mentioned technical problem, this utility model embodiment provides the dummy load circuit of a kind of power circuit, including
Current sampling circuit, comparison circuit, the first on-off circuit, second switch circuit, transistor and dummy resistance；Wherein: electric current
Sample circuit is for gathering the output electric current of power circuit, and exports the sampled voltage corresponding to exporting electric current；Comparison circuit
Reference with the outfan of current sampling circuit with corresponding to predetermined threshold value electric current respectively of first input end and the second input is electric
Piezoelectricity connects, and comparison circuit is used for comparing the size of sampled voltage and reference voltage, and when exporting electric current less than threshold current
Output conducting enables signal；First on-off circuit is for being turned on or off according to the control signal of outside input；Second switch electricity
The input on road electrically connects with the outfan of comparison circuit and the outfan of the first on-off circuit respectively, and second switch circuit is used for
Only disconnect at the first on-off circuit and receive conducting when conducting enables signal；The control input of transistor and second switch
The outfan electrical connection of circuit, the first end of transistor electrically connects with the outfan of power circuit, and the second end of transistor is with false
Ground connection after load resistance series connection；Transistor for working in magnifying state when second switch circuit turn-on, and makes fictitious load electricity
Resistance accesses the outfan of power circuit, and works in cut-off state when second switch circuit disconnects so that dummy resistance and
The outfan of power circuit disconnects.
This utility model is at least up to one of following beneficial effect:
1, the dummy load circuit of this utility model embodiment is in the case of the output electric current of power circuit is less, can be automatically
Dummy resistance is accessed the outfan of power circuit, it is ensured that the testing circuit relevant to power circuit will not can't detect power supply
The output electric current of circuit, does not work and power cutoff circuit from without erroneous judgement power circuit, it is ensured that power circuit exists
Working stability under small area analysis；
2, the dummy load circuit of this utility model embodiment is simultaneously according to the sampling electricity corresponding to power circuit output electric current
Pressure and the comparative result of the reference voltage corresponding to predetermined threshold value electric current and the control signal of outside input, determine whether by
Dummy resistance accesses the outfan of power circuit, therefore controls more accurately, flexibly；
3, the dummy load circuit simple in construction of this utility model embodiment, low cost.
Accompanying drawing explanation
In order to be illustrated more clearly that the technical scheme in this utility model embodiment, required in embodiment being described below
Accompanying drawing to be used is briefly introduced, it should be apparent that, the accompanying drawing in describing below is only enforcements more of the present utility model
Example, from the point of view of those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to attached according to these
Figure obtains other accompanying drawing.
Fig. 1 shows the circuit theory of the dummy load circuit of a kind of power circuit according to this utility model one embodiment
Figure.
Detailed description of the invention
Below in conjunction with the accompanying drawings this utility model is made and further illustrating.
Fig. 1 shows the circuit theory of the dummy load circuit of a kind of power circuit according to this utility model one embodiment
Figure.Refer to shown in Fig. 1, include current sampling circuit according to the dummy load circuit of the power circuit of this utility model one embodiment
1, comparison circuit the 2, first on-off circuit 3, second switch circuit 4, transistor 5 and dummy resistance R5.
Current sampling circuit 1 is for gathering the output electric current of power circuit 9, and exports the sampling electricity corresponding to output electric current
Pressure V1.The first input end of comparison circuit 2 and the second input respectively with the outfan of current sampling circuit 1 and corresponding to presetting
The reference voltage V2 electrical connection of threshold current, for comparing sampled voltage V1 and the size of reference voltage V2, and at power circuit 9
Output electric current less than threshold current time output conducting enable signal.In general, the output electric current of power circuit 9 and sampling electricity
Direct proportionality between pressure V1, like this, when sampled voltage V1 is less than reference voltage V2, i.e. means power circuit 9
Output electric current less than preset threshold current, comparison circuit 2 output conducting enable signal.
First on-off circuit 3 is turned on or off for control signal P_DO according to outside input, control signal P_DO
Can be given by external microcontroller.The input of second switch circuit 4 respectively with outfan and first on-off circuit of comparison circuit 2
The outfan electrical connection of 3, for only disconnecting at the first on-off circuit 3 and receiving conducting when conducting enables signal.
The input that controls of transistor 5 electrically connects with the outfan of second switch circuit 4, the first end of transistor 5 and electricity
Source circuit 9 outfan electrical connection, the second end of transistor 5 connect with dummy resistance R5 after ground connection.Transistor 5 is for the
Two on-off circuits 4 work in magnifying state when turning on, and make dummy resistance R5 access the outfan of power circuit 9, and the
Two on-off circuits 4 work in cut-off state when disconnecting, so that the outfan of dummy resistance R5 and power circuit 9 disconnects.
In the present embodiment, the first on-off circuit 3 is made up of a NPN audion Q1；The base stage of the oneth NPN audion Q1
For receiving control signal P_DO of outside input, the colelctor electrode of a NPN audion Q1 constitutes the output of the first on-off circuit 3
Hold, and the colelctor electrode of a NPN audion Q1 and the first power supply VCC electrically connect, the grounded emitter of a NPN audion Q1.
In the present embodiment, second switch circuit 4 is made up of the 2nd NPN audion Q2；The base stage of the 2nd NPN audion Q2
Constituting the input of second switch circuit 4, the emitter stage of the 2nd NPN audion Q2 constitutes the outfan of second switch circuit 4, the
The colelctor electrode of two NPN audion Q2 electrically connects with second source VDD.
In the present embodiment, transistor 5 is the 3rd NPN audion Q3, the control input of transistor 5, the first end and
Two ends are respectively the base stage of the 3rd NPN audion Q3, collector and emitter.
In the present embodiment, dummy load circuit includes the bleeder circuit 6 for output reference voltage V2.Bleeder circuit 6 wraps
Include the first resistance R3 and the second resistance R4 being serially connected.One end of first resistance R3 electrically connects with second source VDD, the first electricity
The other end of resistance R3 and one end electrical connection of the second resistance R4, the other end ground connection of the second resistance R4.Comparison circuit 2 is by amplifier OP
Constitute, the end of oppisite phase of amplifier OP, in-phase end and outfan respectively constitute the first input end of comparison circuit 2, the second input and
Outfan.The power input of amplifier OP is electrically connected to the first power supply VCC, the earth terminal ground connection of amplifier OP, the first resistance R3's
The common contact of one end of the other end and the second resistance R4 is connected to the in-phase end of amplifier OP.Reference voltage V2=(VDD*R4)/(R3+
R4), reference voltage V2 is also fixing in the case of resistance R3, R4 are fixing.
The operation principle of the dummy load circuit of a kind of power circuit according to this utility model one embodiment approximately as:
When control signal P_DO of outside input is high level, a NPN audion Q1 conducting, a now NPN tri-
The collector voltage of pole pipe Q1 is pulled low, and therefore the 2nd NPN audion Q2 is not turned on, the 3rd NPN audion Q3 and fictitious load electricity
Resistance R5 does not works.When control signal P_DO of outside input is low level, a NPN audion Q1 disconnects, if now adopting
Sample voltage V1 is more than reference voltage V2, then amplifier OP output low level signal, and now the 2nd NPN audion Q2 is not turned on, false negative
Carry resistance R5 not work；If sampled voltage V1 is less than reference voltage V2, then (i.e. conducting enables letter to amplifier OP output high level signal
Number), therefore the 2nd NPN audion Q2 conducting, the 3rd NPN audion Q3 works in magnifying state, so that dummy resistance R5 connects
Enter the outfan of power circuit 9, it is ensured that the testing circuit relevant to power circuit 9 will not can't detect the output of power circuit 9
Electric current, from the power cutoff circuit 9 without erroneous judgement power circuit 9 not work, it is ensured that power circuit 9 is under small area analysis
Working stability.
The dummy load circuit of this utility model embodiment can be used for the power circuit of automotive lighting, especially a kind of LED car
The power circuit of lamp illumination, now LED car lamp can include but not limited to be in automobile LED headlight, LED car atmosphere lamp or
LED daytime running lamps etc..
The dummy load circuit of this utility model embodiment is simultaneously according to the sampled voltage corresponding to power circuit output electric current
With the comparative result of the reference voltage corresponding to predetermined threshold value electric current and the control signal of outside input, determine whether vacation
Load resistance accesses the outfan of power circuit, therefore controls more accurately, flexibly.Additionally, this dummy load circuit also has knot
Structure is simple, the advantage of low cost.
Obviously, those skilled in the art can carry out various change and modification without deviating from this practicality to this utility model
Novel spirit and scope.So, if of the present utility model these amendment and modification belong to this utility model claim and
Within the scope of its equivalent technologies, then this utility model is also intended to comprise these change and modification.
Claims (7)
1. the dummy load circuit of a power circuit, it is characterised in that include current sampling circuit, comparison circuit, the first switch
Circuit, second switch circuit, transistor and dummy resistance；Wherein:
Described current sampling circuit is for gathering the output electric current of described power circuit, and exports corresponding to described output electric current
Sampled voltage；
The first input end of described comparison circuit and the second input respectively with the outfan of described current sampling circuit and corresponding
Reference voltage in predetermined threshold value electric current electrically connects, and comparison circuit is big for relatively described sampled voltage and described reference voltage
Little, and output conducting enables signal when described output electric current is less than described threshold current；
Described first on-off circuit is for being turned on or off according to the control signal of outside input；
The input of described second switch circuit defeated with the outfan of described comparison circuit and described first on-off circuit respectively
Going out end electrical connection, second switch circuit enables signal for only disconnecting at described first on-off circuit and receive described conducting
Time conducting；
The input that controls of described transistor electrically connects with the outfan of described second switch circuit, the first end of described transistor
Electrically connect with the outfan of described power circuit, the second end of described transistor connect with described dummy resistance after ground connection；Institute
State transistor for working in magnifying state when described second switch circuit turn-on, and it is described to make described dummy resistance access
The outfan of power circuit, and work in cut-off state when described second switch circuit disconnects, so that described dummy resistance
Disconnect with the outfan of described power circuit.
The dummy load circuit of a kind of power circuit the most as claimed in claim 1, it is characterised in that described first on-off circuit by
Oneth NPN audion is constituted；The base stage of a described NPN audion is for receiving the control signal of described outside input, described
The colelctor electrode of the oneth NPN audion constitutes the outfan of described first on-off circuit, and the colelctor electrode of a described NPN audion
Electrically connect with the first power supply, the grounded emitter of a described NPN audion.
The dummy load circuit of a kind of power circuit the most as claimed in claim 1, it is characterised in that described second switch circuit by
2nd NPN audion is constituted；The base stage of described 2nd NPN audion constitutes the input of described second switch circuit, and described the
The emitter stage of two NPN audions constitutes the outfan of described second switch circuit, the colelctor electrode of described 2nd NPN audion and the
Two power supply electrical connections.
The dummy load circuit of a kind of power circuit the most as claimed in claim 1, it is characterised in that described transistor is the 3rd
NPN audion, described transistor control input, the first end and the second end be respectively described 3rd NPN audion base stage,
Collector and emitter.
The dummy load circuit of a kind of power circuit the most as claimed in claim 1, it is characterised in that described dummy load circuit includes
For exporting the bleeder circuit of described reference voltage.
The dummy load circuit of a kind of power circuit the most as claimed in claim 5, it is characterised in that described comparison circuit is by amplifier
Constituting, the end of oppisite phase of described amplifier, in-phase end and outfan respectively constitute the first input end of described comparison circuit, the second input
End and outfan.
The dummy load circuit of a kind of power circuit the most as claimed in claim 6, it is characterised in that described bleeder circuit includes phase
The first resistance connected mutually and the second resistance；One end of described first resistance electrically connects with second source, described first resistance
The other end electrically connects with one end of described second resistance, the other end ground connection of described second resistance；
The common contact of one end of the other end of described first resistance and described second resistance is connected to the in-phase end of described amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620563829.7U CN205792219U (en) | 2016-06-13 | 2016-06-13 | A kind of dummy load circuit of power circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620563829.7U CN205792219U (en) | 2016-06-13 | 2016-06-13 | A kind of dummy load circuit of power circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205792219U true CN205792219U (en) | 2016-12-07 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620563829.7U Active CN205792219U (en) | 2016-06-13 | 2016-06-13 | A kind of dummy load circuit of power circuit |
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| Country | Link |
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| CN (1) | CN205792219U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111585457A (en) * | 2020-05-11 | 2020-08-25 | 西安新摩尔半导体有限公司 | Power adapter and electronic equipment |
| CN111799858A (en) * | 2020-06-17 | 2020-10-20 | 维沃移动通信有限公司 | Protection circuit, detection method and device thereof, electronic device and medium |
| CN112327023A (en) * | 2020-10-10 | 2021-02-05 | 浙江晨泰科技股份有限公司 | Electric energy meter with equivalent load circuit |
| CN115085336A (en) * | 2022-07-22 | 2022-09-20 | 深圳市创芯微微电子有限公司 | Dynamic load circuit for charging equipment, dynamic load adjusting method and charging equipment |
-
2016
- 2016-06-13 CN CN201620563829.7U patent/CN205792219U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111585457A (en) * | 2020-05-11 | 2020-08-25 | 西安新摩尔半导体有限公司 | Power adapter and electronic equipment |
| CN111799858A (en) * | 2020-06-17 | 2020-10-20 | 维沃移动通信有限公司 | Protection circuit, detection method and device thereof, electronic device and medium |
| CN111799858B (en) * | 2020-06-17 | 2022-05-10 | 维沃移动通信有限公司 | Protection circuit, detection method and device thereof, electronic device and medium |
| CN112327023A (en) * | 2020-10-10 | 2021-02-05 | 浙江晨泰科技股份有限公司 | Electric energy meter with equivalent load circuit |
| CN112327023B (en) * | 2020-10-10 | 2023-05-23 | 浙江晨泰科技股份有限公司 | Electric energy meter with equivalent load circuit |
| CN115085336A (en) * | 2022-07-22 | 2022-09-20 | 深圳市创芯微微电子有限公司 | Dynamic load circuit for charging equipment, dynamic load adjusting method and charging equipment |
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