CN207318569U - Direct current sample circuit - Google Patents
Direct current sample circuit Download PDFInfo
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- CN207318569U CN207318569U CN201721034200.4U CN201721034200U CN207318569U CN 207318569 U CN207318569 U CN 207318569U CN 201721034200 U CN201721034200 U CN 201721034200U CN 207318569 U CN207318569 U CN 207318569U
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Abstract
It the utility model is related to a kind of direct current sample circuit, including input circuit, signal generating circuit, comparison circuit, isolation circuit and output amplifier, the input circuit, the signal generating circuit and the isolation circuit are respectively connected to the comparison circuit, and the output amplifier is connected to the isolation circuit.The analog signal of input circuit input voltage is converted into the pwm signals that frequency with input direct voltage size variation is certain, duty cycle is indefinite by above-mentioned direct current sample circuit by comparison circuit, above-mentioned pwm signals are after isolation circuit is handled, the DC voltage sampled signal of analog quantity is converted to by filter circuit again, the DC voltage sampled signal and DC voltage change in direct ratio, sampled signal precision is high, and the linearity is high, cost is low.
Description
Technical field
It the utility model is related to sample circuit technical field, and in particular to a kind of direct current sample circuit.
Background technology
The all purposes that complete DC voltage sampling, isolate and follow of DC voltage sampling, sampling is to turn high voltage direct current
Change the low-voltage direct of equal proportion into, isolation circuit is that it is sampled circuit to follow in order to which the ground of microcontroller and DC voltage isolates
Direct current sampled voltage afterwards and DC voltage change in direct ratio.
Traditional DC voltage sample circuit is as shown in Figure 1, this circuit is to use operational amplifier U9A and optocoupler U3 groups
Into optocoupler U3 composition isolation circuits, operational amplifier U9A composition voltage follower circuits, direct current input sample is by resistance and light
After the phototriode partial pressure of coupling, then obtained after following circuit, this circuit shortcoming is the output voltage of voltage sample and straight
It is disproportionate to flow input voltage change, linear bad, output accuracy is not high.
Another DC voltage sample circuit as shown in Fig. 2, DC voltage by bleeder circuit partial pressure after, through operational amplifier
The voltage follower circuit and integral adjustment circuit of 1U3A, 1U3B composition, then linear optical coupling isolation circuit, direct current are sampled through resistance
After RC4 partial pressures, circuit output direct current sampled signal is followed through 1U5A compositions, this direct current sampled signal and d. c. voltage signal
Change in direct ratio, linear conditions are good, and output accuracy is also high, but of high cost.
Utility model content
In view of this, it is necessary to which the direct current sample circuit that a kind of output accuracy is high, cost is low is provided.
A kind of direct current sample circuit, including input circuit, signal generating circuit, comparison circuit, isolation circuit and output are put
Big circuit, the input circuit, the signal generating circuit and the isolation circuit are respectively connected to the comparison circuit, described
Output amplifier is connected to the isolation circuit.
Further, the comparison circuit includes the first operational amplifier, and the input circuit is connected to first fortune
The reverse input end of amplifier is calculated, the signal generating circuit is connected to the noninverting input of first operational amplifier, institute
State the output terminal that isolation circuit is connected to the comparison circuit.
Further, the input circuit includes sequentially connected sampling bleeder circuit and voltage follower circuit, the electricity
Pressure follows the output terminal of circuit to be connected to the reverse input end of first operational amplifier.
Further, the sampling bleeder circuit includes first resistor and the first capacitance, and the voltage follower circuit includes
Second operational amplifier, described first resistor one end are electrically connected the noninverting input of second operational amplifier, another termination
Ground, first capacitance are in parallel with the first resistor.
Further, the isolation circuit is digital optical coupling isolation circuit, it includes digital optocoupler, the numeral optocoupler bag
Including the first pin, second pin, the 4th pin and the 5th pin, first pin is electrically connected DC power supply, and described second
Pin is electrically connected the input terminal of the comparison circuit, and the 5th pin is electrically connected another DC power supply.
Further, the direct current sample circuit also filter circuit, the input terminal of the filter circuit are electrically connected described the
Four pins, the output terminal of the filter circuit are electrically connected the output amplifier.
Further, the direct current sample circuit further includes the voltage input end for input sample voltage, the voltage
Input terminal is electrically connected the sampling bleeder circuit.
Further, the signal generating circuit includes triangle wave generating circuit, and the triangle wave generating circuit includes the
Three operational amplifiers, diode and the second capacitance, the reverse input end electrical connection comparison of the 3rd operational amplifier are electric
Road, the both ends of the diode connect the noninverting input and output terminal of the 3rd operational amplifier respectively；The capacitance one
End is electrically connected the output terminal of the 3rd operational amplifier, other end ground connection.
Further, the output amplifier includes four-operational amplifier and second resistance, the second resistance
Both ends are electrically connected the reverse input end and output terminal of the four-operational amplifier.
Further, the direct current sample circuit further includes the voltage output end for exporting sampled voltage, the voltage
Output terminal is electrically connected the output terminal of the second resistance and the four-operational amplifier.
Above-mentioned direct current sample circuit is by direct current sampled voltage by analog signal through over-sampling bleeder circuit, voltage follow electricity
Road, signal generating circuit, comparison circuit are converted to digital signal, then are incited somebody to action by isolation circuit, filter circuit, output amplifier
Digital signal is converted to the DC voltage sampled signal output of simulation, is isolated in whole process using isolation circuit, adopted
Sample precision is high, and cost is low.
Brief description of the drawings
Fig. 1 is a kind of sample circuit figure of prior art.
Fig. 2 is the sample circuit figure of another prior art.
Fig. 3 is the structure diagram of the direct current sample circuit of one embodiment of the utility model.
Fig. 4 is the circuit structure diagram of the direct current sample circuit of one embodiment of the utility model.
Embodiment
The utility model is described in detail below with reference to specific embodiments and the drawings.
Referring to Fig. 3, a kind of direct current sample circuit 100 of the utility model embodiment is shown, including voltage input end
110th, input circuit 120, comparison circuit 130, signal generating circuit 140, isolation circuit 150, filter circuit 160, output amplification
Circuit 170 and voltage output end 180, input circuit 120 include sampling bleeder circuit 121 and voltage follower circuit 122, and voltage is defeated
Enter end 110, sampling bleeder circuit 121, voltage follower circuit 122 and comparison circuit 130 to be sequentially connected, signal generating circuit 140
Be respectively connected to comparison circuit 130 with isolation circuit 150, isolation circuit 150, filter circuit 160, output amplifier 170 with
And voltage output end 180 is sequentially connected.Direct current sampled voltage is initially analog signal, by 110 input direct-current of voltage input end
Electricity occurs for sample circuit 100, sampling bleeder circuit 121, voltage follower circuit 121, signal through direct current sampling bleeder circuit 100
Road 140, comparison circuit 130 are converted to digital signal, then by isolation circuit 150, filter circuit 160, output amplifier 170
The DC voltage sampled signal of simulation is converted digital signals into, the straight of the simulation is finally exported by voltage output end 180 again
Flow voltage sampling signal.
Please with reference to Fig. 4, in the present embodiment, it is preferred that signal generating circuit 130 is triangle wave generating circuit, every
It is digital optical coupling isolation circuit from circuit 150, filter circuit 160 is RC low-pass filter circuits.
Sampling bleeder circuit 121 includes resistance 1R90,1R91,1R92,1R93 and capacitance 1C39, voltage input end, electricity
Resistance 1R93,1R90,1R92 and 1R91 are sequentially connected, resistance 1R91 ground connection, and capacitance 1C39 is in parallel with resistance 1R91.
Voltage follower circuit 122 includes operational amplifier 1U1A, resistance 1R89 and capacitance C182, operational amplifier 1U1A
Reverse input end connection output terminal, the output terminal of resistance 1R89 one end concatenation operation amplifiers 1U1A, the other end connection capacitance
One end ground connection of C182, capacitance C182 away from resistance 1R89.The input in the same direction of the operational amplifier 1U1A of voltage follower circuit 122
End is connected to the capacitance 1C39 and resistance 1R91 of sampling bleeder circuit 121.
Comparison circuit 130 includes operational amplifier U16A, reverse input end and the voltage follow electricity of operational amplifier U16A
The resistance 1R89 on road 122 is connected with capacitance C182, the cathode of the 3rd pin connection DC power supply of operational amplifier U16A, and the tenth
Two pins connect the anode of DC power supply.
Signal generating circuit 140 includes operational amplifier U16B, diode D20, capacitance C181, C183 and resistance
R245, R246, R247, R248, R249, R255, R256, R260, R261, the cathode of diode D20, resistance R246 and 248 points
The output terminal of operational amplifier U16B is not connected to, and capacitance C181 one end connection resistance R248's and operational amplifier U16B is reverse
Input terminal, other end ground connection, one end connection power supplys of the resistance R246 away from operational amplifier U16B, cathode, the electricity of diode D20
The noninverting input of resistance R249,247 and operational amplifier U16B are sequentially connected.Capacitance C183 one end is connected to resistance R247 and fortune
Calculate the noninverting input of amplifier U16B, other end ground connection；Resistance R245 one end is grounded, the other end, the resistance of resistance R245
The noninverting input of R260,261 and operational amplifier U16B are sequentially connected；One end of resistance R256 is connected to capacitance C181 and fortune
The reverse input end of amplifier U16B is calculated, the other end is connected to the noninverting input of the operational amplifier U16A of comparison circuit 130,
Resistance R255 is in parallel with resistance R256.
Isolation circuit 150 includes digital optocoupler IU22, resistance R250 and capacitance 1C3, and digital optocoupler IU22 draws including first
Foot（That is the anode of photodiode）, second pin, the 4th pin and the 5th pin, first pin and the 5th pin point
Different DC power supplies is not connected, and the second pin of the digital optocoupler IU22 of resistance R250 one end connection, the other end, which is electrically connected, to be compared
The input terminal of the operational amplifier U16A of circuit, capacitance 1C3 one end and the second pin of resistance R250 and digital optocoupler IU22 connect
Connect, other end ground connection.
Filter circuit 160 includes electrolytic capacitor 1C14, resistance 1R278, adjustable resistance RC1 and resistance 1R279, electrolytic capacitor
The anode ground connection of 1C14, cathode, adjustable resistance RC1 and the resistance 1R279 of electrolytic capacitor 1C14 be sequentially connected, resistance 1R278 with
Capacitance 1C14 is in parallel, and the one end of resistance 1R279 away from adjustable resistance RC1 is connected to the digital optocoupler IU22's of isolation circuit 130
4th pin.
Output amplifier 170 includes operational amplifier 1U17 and resistance 1R278, the input in the same direction of operational amplifier 1U17
End is connected to cathode, adjustable resistance RC1 and the resistance 1R278 of the electrolytic capacitor 1C14 of filter circuit, operational amplifier 1U17's
Output terminal is connected to voltage output end 180, the 4th pin connection DC power anode of operational amplifier 1U17, resistance 1R278
Both ends be respectively connected to the reverse input end and output terminal of operational amplifier 1U17.
During work, direct current sampled voltage is analog signal during beginning, and direct current sampled voltage is adopted through the input of voltage input end 110
Sample bleeder circuit 121, following by inputting voltages circuit 122 after sampled 121 voltage division processing of bleeder circuit, then absorbed through capacitance C182
Interference signal, recently enters comparison circuit 130, and synchronous signal occurs the stability triangle ripple signal that circuit 140 produces and also inputs ratio
Compared with circuit 130, comparison circuit 130 by the triangular signal of fixed frequency compared with direct current sampled voltage, and produce one group
For duty cycle with the pwm signal a of DC voltage change, direct current sampled voltage is converted into digital signal by analog signal.Direct current samples
Voltage is bigger, and the duty cycle of pwm signals a is smaller on the contrary, conversely, the duty cycle of pwm signals a is bigger.
Then, pwm signals a is turned the pwm signal a input isolation circuits 150, isolation circuit 150 by comparison circuit 130
Change the pwm signal b into, when pwm signals a is in high level, pwm signals b is low level；Conversely, pwm signals b is high level,
Thus pwm signals a is converted into change opposite pwm signals b with it.
Then, by pwm signal b input filter circuits 160, pwm signals b is converted into isolation circuit 150 by filter circuit 160
Analog signal, direct current sampled voltage are converted into analog signal by digital signal again.
Finally, filter circuit 160 puts above-mentioned analog signal input and output amplifying circuit 170 through output amplifier 170
Exported after big processing to voltage output end 180.
It can be seen from the above that above-mentioned direct current sample circuit 100 by direct current sampled voltage by analog signal through over-sampling bleeder circuit
121st, voltage follower circuit 122, signal generating circuit 140, comparison circuit 130 are converted to digital signal, then by isolation circuit
150th, filter circuit 160, output amplifier 170 convert digital signals into the DC voltage sampled signal output of simulation,
Isolated in whole process using isolation circuit 150, sampling precision is high, and cost is low.
It should be noted that the utility model is not limited to the above embodiment, it is according to the present utility model to create essence
God, those skilled in the art can also make other changes, these changes done according to the creative spirit of the utility model, all
Should be within the scope of the utility model be claimed.
Claims (10)
1. a kind of direct current sample circuit, it is characterised in that including input circuit, signal generating circuit, comparison circuit, isolation circuit
And output amplifier, the input circuit, the signal generating circuit and the isolation circuit are respectively connected to the comparison
Circuit, the output amplifier are connected to the isolation circuit.
2. direct current sample circuit as claimed in claim 1, it is characterised in that the comparison circuit includes the first operation amplifier
Device, the input circuit are connected to the reverse input end of first operational amplifier, and the signal generating circuit is connected to institute
The noninverting input of the first operational amplifier is stated, the isolation circuit is connected to the output terminal of the comparison circuit.
3. direct current sample circuit as claimed in claim 2, it is characterised in that the input circuit includes sequentially connected sampling
Bleeder circuit and voltage follower circuit, the output terminal of the voltage follower circuit are connected to the reverse of first operational amplifier
Input terminal.
4. direct current sample circuit as claimed in claim 3, it is characterised in that it is described sampling bleeder circuit include first resistor and
First capacitance, the voltage follower circuit include the second operational amplifier, and described first resistor one end is electrically connected second fortune
The noninverting input of amplifier is calculated, the other end is grounded, and first capacitance is in parallel with the first resistor.
5. direct current sample circuit as claimed in claim 2, it is characterised in that the isolation circuit is digital light-coupled isolation electricity
Road, it includes digital optocoupler, and the numeral optocoupler includes the first pin, second pin, the 4th pin and the 5th pin, described
First pin is electrically connected DC power supply, and the second pin is electrically connected the input terminal of the comparison circuit, the 5th pin electricity
Connect another DC power supply.
6. direct current sample circuit as claimed in claim 5, it is characterised in that filter circuit is further included, the filter circuit
Input terminal is electrically connected the 4th pin, and the output terminal of the filter circuit is electrically connected the output amplifier.
7. direct current sample circuit as claimed in claim 1, it is characterised in that further include defeated for the voltage of input sample voltage
Enter end, the voltage input end is electrically connected the sampling bleeder circuit.
8. direct current sample circuit as claimed in claim 1, it is characterised in that the signal generating circuit includes triangular wave
Circuit, the triangle wave generating circuit include the 3rd operational amplifier, diode and the second capacitance, the 3rd operational amplifier
Reverse input end be electrically connected the comparison circuit, the both ends of the diode connect the same of the 3rd operational amplifier respectively
To input terminal and output terminal；Described capacitance one end is electrically connected the output terminal of the 3rd operational amplifier, other end ground connection.
9. direct current sample circuit as claimed in claim 1, it is characterised in that the output amplifier is put including the 4th computing
Big device and second resistance, the both ends of the second resistance are electrically connected the reverse input end of the four-operational amplifier and defeated
Outlet.
10. direct current sample circuit as claimed in claim 9, it is characterised in that further include the voltage for exporting sampled voltage
Output terminal, the voltage output end are electrically connected the output terminal of the second resistance and the four-operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721034200.4U CN207318569U (en) | 2017-08-17 | 2017-08-17 | Direct current sample circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721034200.4U CN207318569U (en) | 2017-08-17 | 2017-08-17 | Direct current sample circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207318569U true CN207318569U (en) | 2018-05-04 |
Family
ID=62432747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721034200.4U Active CN207318569U (en) | 2017-08-17 | 2017-08-17 | Direct current sample circuit |
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| Country | Link |
|---|---|
| CN (1) | CN207318569U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109085414A (en) * | 2018-08-10 | 2018-12-25 | 深圳和而泰智能控制股份有限公司 | Voltage detection method and device |
| CN109633257A (en) * | 2018-12-25 | 2019-04-16 | 彭志辉 | A kind of accurate wattful power messurement method of measurement |
| CN109633258A (en) * | 2019-01-09 | 2019-04-16 | 彭志辉 | A kind of wattful power messurement circuit |
| CN109752584A (en) * | 2019-01-14 | 2019-05-14 | 彭志辉 | A kind of periodic signal effective value measurement method |
| CN115541972A (en) * | 2022-11-30 | 2022-12-30 | 深圳市捷益达电子有限公司 | Direct-current voltage isolation sampling method, device and circuit |
-
2017
- 2017-08-17 CN CN201721034200.4U patent/CN207318569U/en active Active
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109085414A (en) * | 2018-08-10 | 2018-12-25 | 深圳和而泰智能控制股份有限公司 | Voltage detection method and device |
| CN109633257A (en) * | 2018-12-25 | 2019-04-16 | 彭志辉 | A kind of accurate wattful power messurement method of measurement |
| CN109633257B (en) * | 2018-12-25 | 2020-10-09 | 彭志辉 | Active power measuring method with accurate measurement |
| CN109633258A (en) * | 2019-01-09 | 2019-04-16 | 彭志辉 | A kind of wattful power messurement circuit |
| CN109633258B (en) * | 2019-01-09 | 2020-10-02 | 彭志辉 | Active power measuring circuit |
| CN109752584A (en) * | 2019-01-14 | 2019-05-14 | 彭志辉 | A kind of periodic signal effective value measurement method |
| CN109752584B (en) * | 2019-01-14 | 2020-10-09 | 彭志辉 | Method for measuring effective value of periodic signal |
| CN115541972A (en) * | 2022-11-30 | 2022-12-30 | 深圳市捷益达电子有限公司 | Direct-current voltage isolation sampling method, device and circuit |
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