CN203299259U - Resistor-free current sampling circuit - Google Patents
Resistor-free current sampling circuit Download PDFInfo
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- CN203299259U CN203299259U CN2013203694481U CN201320369448U CN203299259U CN 203299259 U CN203299259 U CN 203299259U CN 2013203694481 U CN2013203694481 U CN 2013203694481U CN 201320369448 U CN201320369448 U CN 201320369448U CN 203299259 U CN203299259 U CN 203299259U
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- resistor
- operational amplifier
- sampling
- resistance
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Abstract
The utility model discloses a resistor-free current sampling circuit, comprising two sampling input lines and an output end OUT, wherein the two sampling input lines are respectively connected with a positive input end and a negative input end of an operational amplifier U1 through a resistor R1 and a resistor R2, an output end of the operational amplifier U1 is respectively connected with the output end OUT through a resistor R4 and grounded through a capacitor C2, a resistor R3 is connected between the output end and the negative input end of the operational amplifier U1, and the positive input end of the operational amplifier U1 is grounded through a capacitor C1. The scheme solves the defects of adopting resistor s for sampling in the existing sampling circuit, cannot cause variation of sampling precision due to resistance variation because of external factors or resistors' factors, and reduces the potential safety hazards for the user in application process; in addition, the resistor is canceled, the energy consumption during the application process is decreased, the utilization of resistors is reduced, the manufacturing operation and processing are reduced, and the cost is reduced.
Description
Technical field
The utility model relates to a kind of improvement technology of current sampling circuit.
Background technology
The mode of using in the current sampling circuit of commonly using at present is all that voltage sample is carried out at resistance two ends, passes to corresponding subordinate circuit after then by MCU, processing and processes.In use there are some hidden danger in such processing mode, if this sampling resistor is not carried out some corresponding protection, likely can cause resistance because external cause and resistance diminishes or short circuit, making the sample circuit precision reduce even lost efficacy, electric current also has the part heat dissipation through this resistance the time, wasted energy.
The utility model content
The utility model to provide a kind of and need not to use resistance can sample, use safety, precision is high, cost is low non-resistance current sampling circuit in order to solve the problems of the technologies described above.
The utility model adopts following scheme to realize:
A kind of non-resistance current sampling circuit, comprise two sampling input lines and output terminal OUT, two sampling input lines are connected with positive input terminal, the negative input end of an operational amplifier U1 by resistance R 1, resistance R 2 respectively, the resistance R 4 of passing through respectively of operational amplifier U1 output terminal connects output terminal OUT and passes through capacitor C 2 ground connection, be connected with resistance R 3 between the output terminal of operational amplifier U1 and negative input end, the positive input terminal of operational amplifier U1 is by capacitor C 1 ground connection.
This scheme has solved in present sample circuit the shortcoming of using resistance to sample, not there will be and causes change in resistance to cause that sampling precision changes, and has reduced user's potential safety hazard in use because of external cause or resistance self reason; Cancel resistance, reduced energy consumption in use, reduced simultaneously the use of resistance, reduced manufacturing operation and processing, reduced cost.
Description of drawings
Fig. 1 is the utility model embodiment circuit theory diagrams.
Embodiment
, in order to allow those skilled in the art understand better the technical solution of the utility model, below in conjunction with accompanying drawing, the utility model is further elaborated.
As shown in Figure 1, the non-resistance current sampling circuit that the present embodiment discloses, comprise two sampling input lines and output terminal OUT, two sampling input lines are connected with positive input terminal, the negative input end of an operational amplifier U1 by resistance R 1, resistance R 2 respectively, the resistance R 4 of passing through respectively of operational amplifier U1 output terminal connects output terminal OUT and passes through capacitor C 2 ground connection, be connected with resistance R 3 between the output terminal of operational amplifier U1 and negative input end, the positive input terminal of operational amplifier U1 is by capacitor C 1 ground connection.Output terminal OUT can connect MCU, by MCU, output signal is processed and is calibrated, and reaches design accuracy in advance.
Relative prior art, the utility model has been cancelled sampling resistor, can directly to copper sheet, carry out sampling processing, can avoid two sampling input ends to occur that change in resistance or short circuit cause sampling precision step-down or inefficacy, reduced the potential safety hazard in the use procedure, reduced simultaneously heat dissipation, reduced energy consumption, and reduced circuit cost taken by themselves and manufacturing cost.
It is more than the better implementation of the utility model; need to prove; in the situation that do not deviate from the utility model spirit and essence thereof; adopt other elements with judgement, output function etc. as operational amplifier U1, those of ordinary skill in the art should belong to the protection domain of the appended claim of the utility model when making various corresponding changes and be out of shape according to the utility model.
Claims (1)
1. non-resistance current sampling circuit, comprise two sampling input lines and output terminal OUT, it is characterized in that: two sampling input lines are connected with positive input terminal, the negative input end of an operational amplifier U1 by resistance R 1, resistance R 2 respectively, the resistance R 4 of passing through respectively of operational amplifier U1 output terminal connects output terminal OUT and passes through capacitor C 2 ground connection, be connected with resistance R 3 between the output terminal of operational amplifier U1 and negative input end, the positive input terminal of operational amplifier U1 is by capacitor C 1 ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013203694481U CN203299259U (en) | 2013-06-26 | 2013-06-26 | Resistor-free current sampling circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013203694481U CN203299259U (en) | 2013-06-26 | 2013-06-26 | Resistor-free current sampling circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203299259U true CN203299259U (en) | 2013-11-20 |
Family
ID=49575264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013203694481U Expired - Fee Related CN203299259U (en) | 2013-06-26 | 2013-06-26 | Resistor-free current sampling circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203299259U (en) |
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2013
- 2013-06-26 CN CN2013203694481U patent/CN203299259U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131120 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |