CN206658043U - Current foldback circuit and overcurrent protector - Google Patents
Current foldback circuit and overcurrent protector Download PDFInfo
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- CN206658043U CN206658043U CN201720319844.1U CN201720319844U CN206658043U CN 206658043 U CN206658043 U CN 206658043U CN 201720319844 U CN201720319844 U CN 201720319844U CN 206658043 U CN206658043 U CN 206658043U
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- current
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- triode
- sampling resistor
- foldback circuit
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Abstract
The utility model embodiment discloses a kind of current foldback circuit and overcurrent protector, and the copper strips that the current foldback circuit includes taking shape in the conducting wire on DBC substrates and being mounted in the conducting wire and intercept out according to preliminary dimension from the layers of copper of DBC substrate surfaces forms the current sampling resistor R1 for being sampled to current signal.The overcurrent protector includes above-mentioned current foldback circuit, be connected with current foldback circuit over-current signal process circuit to obtain the current foldback circuit over-current signal exported and be handled and is connected with current foldback circuit and over-current signal process circuit and the drive circuit of controlled driving load respectively.The utility model embodiment is used as current sampling resistor R1 to be sampled to current signal by intercepting the copper strips of the preliminary dimension on DBC substrates, and the voltage stabilization of electric current conversion, overcurrent is big, and circuit reliability is high, reduces the use of resistance, reduces production cost.
Description
Technical field
It the utility model is related to current foldback circuit technical field, more particularly to a kind of current foldback circuit and overcurrent protection
Device.
Background technology
With the development of motor technology and motor driver, increasing motor driver starts requirement and possesses excessively stream
Defencive function, generally, motor driver generally use operational amplifier, comparator or special overcurrent protection IC conducts
Current foldback circuit, commercially, current foldback circuit is welded on the product on DBC substrates, DBC substrates be it is a kind of by
Ceramics insulator covers copper ceramic substrate as bottom plate and covered with layer of metal copper on bottom plate, and still, existing excessively stream is protected
Protection circuit circuit is complicated, component is more and needs to be welded all components, and circuit welding fabrication difficulty is high, is produced into
This height.
Utility model content
The utility model embodiment technical problems to be solved are to provide a kind of current foldback circuit, and circuit structure is simple,
Overcurrent is big, and reliability is high.
The further technical problems to be solved of the utility model embodiment are to provide a kind of overcurrent protector, circuit structure
Simply, reliability is high.
In order to solve the above technical problems, the utility model embodiment provides a kind of current foldback circuit, including take shape in
Conducting wire on DBC substrates and the circuit components being mounted in the conducting wire, the circuit components include using
In the current sampling resistor R1 sampled to current signal, the current sampling resistor R1 is by the layers of copper from DBC substrate surfaces
In the copper strips that intercepts out according to preliminary dimension form.
Further, the circuit components also include being used to detect the voltage signal size on current sampling resistor R1
Triode Q1, the both ends of the current sampling resistor R1 connect the base stage and emitter stage of the triode Q1, and described three respectively
Pole pipe Q1 emitter stage is also connected with power positive end, and colelctor electrode is also connected with power cathode end.
Further, the triode Q1 is PNP type triode.
Further, the circuit components also include the current-limiting resistance R2 and voltage-regulator diode D1 of series connection, the current limliting
Resistance R2 both ends are connected respectively the negative electrode to triode Q1 colelctor electrode and voltage-regulator diode D1, voltage-regulator diode D1's
Anode connection power cathode end.
Second aspect, the utility model embodiment additionally provide a kind of overcurrent protector, including current foldback circuit and mistake
Stream protection circuit be connected with obtain the over-current signal of current foldback circuit output and the over-current signal process circuit that is handled with
And it is connected respectively with current foldback circuit and over-current signal process circuit and the drive circuit of controlled driving load, the excessively stream are protected
Protection circuit is above-mentioned current foldback circuit.
Further, the current foldback circuit also includes being used to detect the voltage signal size on current sampling resistor R1
Triode Q1, the both ends of the current sampling resistor R1 connect the base stage and emitter stage of the triode Q1 respectively, described three
Pole pipe Q1 emitter stage is also connected with power positive end, and the colelctor electrode of the triode Q1 is also sequentially connected in series current-limiting resistance R2 and voltage stabilizing
Diode D1, the voltage-regulator diode D1 negative electrode connection current-limiting resistance R2 and anode connection power cathode end, the excessively stream letter
Number process circuit is taken shape on DBC substrates, and the over-current signal process circuit has two-way input, the two-way input point
Be not connected to one end that current sampling resistor R1 is connected with triode Q1 base stage and current-limiting resistance R2 and voltage-regulator diode D1 it
Between circuit on, the over-current signal process circuit has two-way output end, and the two-way output end connects drive circuit respectively
With power cathode end.
Further, the drive circuit is taken shape on DBC substrates, and the drive circuit has two-way input and two-way
Output end, the two-way input of the drive circuit are respectively connecting to what current sampling resistor R1 was connected with triode Q1 base stage
One end and the output end all the way of over-current signal process circuit, the two-way output end of the drive circuit connect power cathode end respectively
And load.
Further, the drive circuit is H-bridge drive circuit.
By using above-mentioned technical proposal, the utility model embodiment has the beneficial effect that：The utility model embodiment
It is used as current sampling resistor R1 for current signal by intercepting copper strips according to preliminary dimension in the layers of copper of DBC substrate surfaces
Sampled, reduce the use of resistance in circuit, reduce production cost；And current sampling resistor R1 is made by copper strips, electric current
The voltage stabilization of conversion, overcurrent is big, and circuit reliability is high.
Brief description of the drawings
Fig. 1 is the electrical block diagram of the utility model overcurrent protector one embodiment connection load.
Fig. 2 is the electricity of shaping of the utility model overcurrent protector one embodiment current foldback circuit on DBC substrates
Line structure schematic diagram.
Fig. 3 is the utility model current foldback circuit one embodiment conducting wire and current sampling resistor R1 in DBC bases
Shaping schematic flow sheet on plate.
Fig. 4 is the utility model current foldback circuit one embodiment conducting wire and current sampling resistor R1 in DBC bases
The idiographic flow schematic diagram of forming step S1 on plate.
Embodiment
The application is described in further detail with specific embodiment below in conjunction with the accompanying drawings.It should be appreciated that following signal
Property embodiment and explanation be only used for explaining the utility model, be not intended as to restriction of the present utility model, moreover, not conflicting
In the case of, the feature in embodiment and embodiment in the application can be combined with each other.
As shown in Figure 1 to Figure 2, the utility model one embodiment provides a kind of current foldback circuit, including takes shape in DBC
Conducting wire on substrate 100 and the circuit components being mounted in the conducting wire, the circuit components include using
In the current sampling resistor R1 sampled to current signal, the current sampling resistor R1 is by the copper from the surface of DBC substrates 100
The copper strips for intercepting out according to preliminary dimension in layer is formed.
The present embodiment is used as current sample by intercepting copper strips according to preliminary dimension in the layers of copper on the surface of DBC substrates 100
Resistance R1 is used to sample current signal, reduces the use of resistance in circuit, reduces production cost；In addition, using copper strips
Circuit as current sampling resistor R1 has the advantages of voltage stabilization that reliability is high, overcurrent is big and electric current is changed.
In one alternate embodiment, the circuit components also include being used to detect the voltage on current sampling resistor R1
The triode Q1, the current sampling resistor R1 of signal magnitude both ends connect base stage and the transmitting of the triode Q1 respectively
Pole, and the emitter stage of the triode Q1 is also connected with power positive end+V, colelctor electrode is also connected with power cathode end-V.
In a specific embodiment, the triode Q1 uses PNP type triode, by by triode Q1 base stage and
Emitter stage is respectively connecting to current sampling resistor R1 both ends, and when current sampling resistor R1 overcurrent increases to, electric current is adopted
The voltage difference at sample resistance R1 both ends also increases, three poles when only the voltage difference at current sampling resistor R1 both ends increases to preset value
Pipe Q1 can just be turned on, by using triode Q1 to detect the voltage signal size on current sampling resistor R1, circuit reliability
It is high.
In another specific embodiment, the triode Q1 uses NPN type triode, the current sampling resistor R1's
Both ends are respectively connecting to triode Q1 colelctor electrode and base stage, and circuit stability is high, and reliability is high.
In one alternate embodiment, the circuit components also include current-limiting resistance R2 and voltage-regulator diode D1, described
Current-limiting resistance R2 one end is connected to triode Q1 colelctor electrode, and the other end is connected to voltage-regulator diode D1 negative electrode, the pole of voltage stabilizing two
Pipe D1 anode connection power cathode end-V.
The present embodiment, to limit the electric current that triode Q1 colelctor electrode exports, can effectively improve this reality by current-limiting resistance R2
With the reliability of new current foldback circuit；On the other hand, by using voltage-regulator diode D1 to limit triode Q1 current collection
The amplitude size of the voltage signal of pole output, the voltage that can effectively avoid current foldback circuit from exporting occur changing and made and excessively stream
Protection circuit connection other circuit job insecurities even damage other circuits, improve current foldback circuit stability and can
By property.
As shown in Figure 3 to Figure 4, the utility model current foldback circuit can be made with the following method：
S1, conducting wire and current sampling resistor R1 are molded in DBC substrates 100；
S2, by addition to current sampling resistor R1 other circuit components be welded to the predeterminated positions of DBC substrates 100 with
Conducting wire is connected.
Wherein, the concrete operation method that conducting wire and current sampling resistor R1 are molded in DBC substrates 100 is as follows：
S11, electric current is determined according to the resistance value of the resistivity of the overlying copper of DBC substrates 100 and required current sampling resistor R1
Sampling resistor R1 size；
S12, obtained current sampling resistor R1 size and conductive circuit pattern are transferred on DBC substrates 100；
S13, DBC substrates 100 are etched to mold conducting wire and the pre- scale as current sampling resistor R1
Very little copper strips.
The two sides of DBC substrates 100 are all covered with metallic copper, according to resistance formula：R=ρ l/S, wherein, copper
Electricalresistivityρ is 1.75 × 10-8, when it is determined that current sampling resistor R1 resistance when, you can be calculated the suitable length of copper strips and
Cross-sectional area, the and because metallic copper that covers is relatively thin on DBC substrates 100, there is tri- kinds of 0.1mm, 0.2mm and 0.3mm different
Thickness specification, so the length and width that need to only design copper strips can obtain the copper strips of predetermined resistance as current sampling resistor
R1；Then the pattern transfer together with conducting wire is carried out after layout design further according to the length and width for the copper strips being calculated
Onto DBC substrates 100, then by the way of acid etching will on DBC substrates except conducting wire and current sampling resistor R1 it
Other outer unwanted copper that cover remove, you can straight forming goes out the copper strips and conductor wire of required size on DBC substrates 100
Road, it will be understood that required copper strips can also also be made by using the mechanical mode of alkali etching or physics certainly and lead
Electric line.
Second aspect, as shown in Fig. 2 one alternative embodiment of the utility model additionally provides a kind of overcurrent protector, bag
Include current foldback circuit 1, be connected with current foldback circuit 1 to obtain the over-current signal of the output of current foldback circuit 1 and be located
The over-current signal process circuit 2 of reason and it is connected respectively with current foldback circuit 1 and over-current signal process circuit 2 and controlled driving
The drive circuit 3 of load 4, the current foldback circuit 1 include being used for the current sampling resistor R1 for sampling current signal,
The current sampling resistor R1 is made up of the copper strips for intercepting out according to preliminary dimension from the layers of copper on the surface of DBC substrates 100.
The present embodiment intercepts out by using in current foldback circuit 1 from the surface of DBC substrates 100 installation preliminary dimension
Copper strips form current sampling resistor R1 to be sampled to current signal, reduce the use of resistance in current foldback circuit, drop
Low production cost, current sampling resistor R1 overcurrent is big and the voltage stability of its electric current conversion is high, can effectively improve excessively stream
The reliability of protector.
In one alternate embodiment, the current foldback circuit 1 also includes being used to detect on current sampling resistor R1
The triode Q1 of voltage signal size, the both ends of the current sampling resistor R1 connect the base stage and hair of the triode Q1 respectively
Emitter-base bandgap grading, the emitter stage of the triode Q1 are also connected with the positive terminal of power supply, and the colelctor electrode of the triode Q1 is also sequentially connected in series limit
Leakage resistance R2 and voltage-regulator diode D1, the voltage-regulator diode D1 negative electrode connect current-limiting resistance R2 and anode connection power cathode
End-V, the over-current signal process circuit 2 have two-way input, and the two-way input is respectively connecting to current sampling resistor
On circuit between one end that R1 is connected with triode Q1 base stage and current-limiting resistance R2 and voltage-regulator diode D1, the excessively stream letter
Number process circuit 2 has two-way output end, and the two-way output end connects drive circuit 3 and power cathode end-V respectively；It is described
Drive circuit 3 has two-way input and two-way output end, and the two-way input of the drive circuit 3 is respectively connecting to electric current and adopted
One end and the output end all the way of over-current signal process circuit 2 that sample resistance R1 is connected with triode Q1 base stage, the driving electricity
The two-way output end on road 3 connects power cathode end-V and load 4 respectively, and the over-current signal process circuit 2 and drive circuit 3 are equal
Take shape on DBC substrates 100.
In a specific embodiment, so that the load 4 is motor as an example, when motor failure stall causes driving electricity
When electric current becomes big in road 3, the current sampling resistor R1 to be connected with drive circuit 3 overcurrent also increases therewith, and then causes electricity
The voltage difference for flowing sampling resistor R1 both ends becomes big so that triode Q1 is turned on and by colelctor electrode after current-limiting resistance R2
For output overcurrent signal to over-current signal process circuit 2, over-current signal process circuit 2 receives one shut-off of output after over-current signal
Signal to control the open circuit of drive circuit 3, makes motor not have electric current by so as to realizing overcurrent protection function, mistake to drive circuit 3
It is simple to flow the circuit structure of protector, reliability is high, in addition, by using the copper strips of preliminary dimension on DBC substrates 100 as electricity
Sampling resistor R1 is flowed, reduces the use of resistance, reduces production cost.
In another alternative embodiment, the over-current signal process circuit 2 and drive circuit 3 are to take shape in DBC bases
Independent circuit module outside plate 100, it can be realized electrically connect with current foldback circuit 1 by conducting wire when in use, side
Just the over-current signal process circuit 2 or drive circuit 3 of difference in functionality are changed according to specific implementation environment, improves overcurrent protection
The practicality of device.
In one alternate embodiment, the voltage stabilizing value of the voltage-regulator diode D1 is 12V, when the both ends of current sampling resistor 1
Voltage difference increase so that cause triode Q1 conducting when, triode Q1 colelctor electrode passes through current-limiting resistance R2 output voltage signals
To voltage-regulator diode D1 cathode terminal, due to voltage-regulator diode D1 pressure stabilization function so that voltage-regulator diode D1 negative electrode and sun
12V voltage signal is formed between pole, the over-current signal process circuit 2 electrically connected with voltage-regulator diode negative electrode can then receive
To 12V voltage signals and a cut-off signals are exported to drive circuit 3 to control the open circuit of drive circuit 3, realize overcurrent protection work(
Energy.It is appreciated that the voltage-regulator diode D1 can also according to the different voltage stabilizing value of specific implementation environmental selection, such as：Voltage stabilizing
Diode D1 voltage stabilizing value is 5V, there is provided it is a variety of to implement selection, the practicality of overcurrent protector can be effectively improved.
In one alternate embodiment, the drive circuit 3 is H-bridge drive circuit, specifically, the H-bridge drive circuit
Realized using 4 N-type metal-oxide-semiconductors, one is exported after excessively stream signal processing circuit 2 receives the over-current signal of triode Q1 outputs
Cut-off signals are to H-bridge drive circuit, 4 metal-oxide-semiconductors shut-off in H-bridge drive circuit, motor is not had electric current by so as to realizing
Overcurrent protection function.The stability and reliability of overcurrent protector can be effectively improved using H-bridge drive circuit.
Particular embodiments described above, the purpose of this utility model, technical scheme and beneficial effect are carried out to enter one
Step describes in detail, should be understood that and the foregoing is only specific embodiment of the utility model, is not used to limit this
The protection domain of utility model, it is all within the spirit and principles of the utility model, any modification for being made, equivalent substitution, change
Enter, should be included within the scope of protection of the utility model.
Claims (8)
1. a kind of current foldback circuit, including the conducting wire that takes shape on DBC substrates and it is mounted in the conducting wire
Circuit components, the circuit components include being used for the current sampling resistor R1 that samples current signal, its feature
It is：The current sampling resistor R1 is made up of the copper strips for intercepting out according to preliminary dimension from the layers of copper of DBC substrate surfaces.
2. current foldback circuit according to claim 1, it is characterised in that：The circuit components also include being used to detect
The triode Q1, the current sampling resistor R1 of voltage signal size on current sampling resistor R1 both ends connect described respectively
Triode Q1 base stage and emitter stage, and the emitter stage of the triode Q1 is also connected with power positive end, colelctor electrode is also connected with electricity
Source negative pole end.
3. current foldback circuit according to claim 2, it is characterised in that：The triode Q1 is PNP type triode.
4. current foldback circuit according to claim 2, it is characterised in that：The circuit components also include the limit of series connection
Leakage resistance R2 and voltage-regulator diode D1, the current-limiting resistance R2 both ends are connected respectively to triode Q1 colelctor electrode and steady
Press diode D1 negative electrode, voltage-regulator diode D1 anode connection power cathode end.
5. a kind of overcurrent protector, including current foldback circuit, be connected with current foldback circuit it is defeated to obtain current foldback circuit
The over-current signal gone out and the over-current signal process circuit that is handled and handled respectively with current foldback circuit and over-current signal
Circuit is connected and the drive circuit of controlled driving load, it is characterised in that：The current foldback circuit is as claimed in claim 1
Current foldback circuit.
6. overcurrent protector according to claim 5, it is characterised in that：The current foldback circuit also includes being used to detect
The triode Q1, the current sampling resistor R1 of voltage signal size on current sampling resistor R1 both ends connect described respectively
Triode Q1 base stage and emitter stage, the emitter stage of the triode Q1 are also connected with power positive end, the collection of the triode Q1
Electrode be also sequentially connected in series current-limiting resistance R2 and voltage-regulator diode D1, the voltage-regulator diode D1 negative electrode connection current-limiting resistance R2 and
Anode connection power cathode end, the over-current signal process circuit are taken shape on DBC substrates, the over-current signal process circuit tool
There is two-way input, the two-way input is respectively connecting to one end that current sampling resistor R1 is connected with triode Q1 base stage
On circuit between current-limiting resistance R2 and voltage-regulator diode D1, the over-current signal process circuit has two-way output end, institute
State two-way output end and connect drive circuit and power cathode end respectively.
7. overcurrent protector according to claim 6, it is characterised in that：The drive circuit is taken shape on DBC substrates, institute
Stating drive circuit has two-way input and two-way output end, and the two-way input of the drive circuit is respectively connecting to electric current and adopted
One end and the output end all the way of over-current signal process circuit that sample resistance R1 is connected with triode Q1 base stage, the drive circuit
Two-way output end connect power cathode end and load respectively.
8. according to the overcurrent protector described in any one of claim 5 ~ 7, it is characterised in that：The drive circuit drives for H bridges
Circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720319844.1U CN206658043U (en) | 2017-03-28 | 2017-03-28 | Current foldback circuit and overcurrent protector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720319844.1U CN206658043U (en) | 2017-03-28 | 2017-03-28 | Current foldback circuit and overcurrent protector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206658043U true CN206658043U (en) | 2017-11-21 |
Family
ID=60316744
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720319844.1U Active CN206658043U (en) | 2017-03-28 | 2017-03-28 | Current foldback circuit and overcurrent protector |
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| Country | Link |
|---|---|
| CN (1) | CN206658043U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107069651A (en) * | 2017-03-28 | 2017-08-18 | 深圳市振华微电子有限公司 | Current foldback circuit, overcurrent protector and current foldback circuit forming method |
-
2017
- 2017-03-28 CN CN201720319844.1U patent/CN206658043U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107069651A (en) * | 2017-03-28 | 2017-08-18 | 深圳市振华微电子有限公司 | Current foldback circuit, overcurrent protector and current foldback circuit forming method |
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