CN203011986U - Direct-current high-voltage isolation sampling circuit - Google Patents
Direct-current high-voltage isolation sampling circuit Download PDFInfo
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- CN203011986U CN203011986U CN 201220562820 CN201220562820U CN203011986U CN 203011986 U CN203011986 U CN 203011986U CN 201220562820 CN201220562820 CN 201220562820 CN 201220562820 U CN201220562820 U CN 201220562820U CN 203011986 U CN203011986 U CN 203011986U
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Abstract
The utility model relates to the technical field of direct-current circuits, and specifically relates to a direct-current high-voltage isolation sampling circuit. The circuit comprises buses to be sampled, an A/D (analog/digital) conversion circuit, an optical coupling isolation circuit and a signal processing unit. A voltage division sampling circuit is serially connected between a positive bus and a negative bus of the buses, an output end of the voltage division sampling circuit is connected with an input end of the A/D conversion circuit, an output end of the A/D conversion circuit is connected with an input end of an optical coupling isolator, and an output end of the optical coupling isolator is connected with the signal processing unit. Compared with the prior art, the direct-current high-voltage isolation sampling circuit is advantageous in that the number of signal processing procedures is small, and the sampling precision is improved; by using the independent A/D conversion circuit, the A/D conversion precision is improved; the circuit is simplified, and the number of devices is lowered; and as signals are isolated, the requirement on an optical coupler is greatly lowered, thereby saving the cost of the circuit.
Description
Technical field
The utility model relates to direct current sample circuit technical field, refers to especially a kind of high direct voltage isolation sample circuit.
Background technology
In various electronic equipments, often need to carry out voltage or current sample to the bus with high direct voltage.In the prior art; usually at first the high direct voltage sampling is the voltage signal of tens millivolts through electric resistance partial pressure; export again the voltage signal of several volts through isolation amplifier; pass through afterwards filtering, amplification and holding circuit; finally send into the A/D converter of CPU; thereby realize isolation measurement and the digital-to-analog conversion of high voltage direct current, reliability and the antijamming capability of while in order to improve straight-flow system, sample circuit carries out electrical isolation with light-coupled isolation or the isolation of voltage Hall to main circuit and control circuit.For this sample circuit, on the one hand because need amplify through two-stage, the processing such as light-coupled isolation, filtering and protection, the intermediate treatment link is more, affect the precision of sample circuit and can not reflect that the small voltage of high voltage direct current fluctuates, in order to improve sampling precision, generally take to use instead the more superior device of performance, as linear optical coupling etc., this has improved cost greatly, and is limited for the raising effect of precision, if although adopt Hall element can improve precision, but cost is high and need the raising dual power supply, has increased the complicacy of circuit; On the other hand, because the built-in A/D converter of CPU only has 10, if rely on merely the A/D converter that CPU carries to carry out analog to digital conversion, conversion accuracy is restricted, the interference of processing links before adding, and the precision of A/D conversion reduces greatly.In addition, because the port resource of CPU is limited, when the need sampled point was many, its port resource usually can not satisfy the demands.
Summary of the invention
The purpose of this utility model be to avoid above-mentioned weak point of the prior art and provide that a kind of processing links is few, sampling precision and the high high direct voltage isolation sample circuit of A/D conversion accuracy.
The purpose of this utility model is achieved through the following technical solutions:
A kind of high direct voltage isolation sample circuit is provided, comprise between the positive bus-bar that is arranged at bus to be sampled and negative busbar and be serially connected with pressure sampling circuit, also comprise A/D change-over circuit, optical coupling isolation circuit and signal processing unit, it is characterized in that: the output terminal of described pressure sampling circuit connects the input end of A/D change-over circuit, the output terminal of described A/D change-over circuit connects the input end of optical coupling isolation circuit, and the output terminal of described optical coupling isolation circuit connects signal processing unit.
Wherein, bus quantity described to be sampled is no less than two-way, is respectively arranged with between the pressure sampling circuit on each road bus and A/D change-over circuit to be controlled by signal processing unit the switch of its conduction and cut-off.
Wherein, described a plurality of switch has a switch conduction at the most in sampling process.
Wherein, described switch is photoelectric relay.
Wherein, described signal processing unit by the multi-channel sampling control circuit to control the conduction and cut-off of each switch.
Wherein, described pressure sampling circuit comprises positive bus-bar and the divider resistance R1 between negative busbar and the divider resistance R2 that is serially connected with successively bus, and the tie point of described divider resistance R1 and divider resistance R2 is as the output terminal of pressure sampling circuit.
Wherein, described A/D change-over circuit comprises analog to digital converter ADS1118.
The beneficial effects of the utility model: a kind of multi-channel DC high pressure sample circuit is provided; output terminal at pressure sampling circuit arranges the A/D change-over circuit; the low-voltage signal that pressure sampling circuit is obtained directly carries out the A/D conversion; and then the digital signal after the A/D conversion is carried out flowing to CPU element after light-coupled isolation; therefore need not to carry out the processing such as amplifier, protection for sampled signal; reduce its middle processing links, greatly improved the precision of sampling.Owing to adopting independently A/D change-over circuit, improve the conversion performance of A/D change-over circuit, and there is no the interference of intermediate treatment link simultaneously, therefore greatly improved the A/D conversion accuracy.Circuit also is simplified on the other hand, has reduced device, and due to substance is isolated well, the requirement of optocoupler is lowered greatly, thereby has saved circuit cost.
Description of drawings
Fig. 1 is the electrical block diagram of the embodiment of the utility model kind multi-channel DC high pressure sample circuit.
Fig. 2 is the pressure sampling circuit of embodiment of the utility model kind multi-channel DC high pressure sample circuit and the circuit diagram of switch.
Fig. 3 is the A/D change-over circuit circuit diagram of the embodiment of the utility model kind multi-channel DC high pressure sample circuit.
Fig. 4 is the multi-channel sampling control circuit circuit diagram of the embodiment of the utility model kind multi-channel DC high pressure sample circuit.
Fig. 5 is the optical coupling isolation circuit circuit diagram of the embodiment of the utility model kind multi-channel DC high pressure sample circuit.
Embodiment
With the following Examples the utility model is further described.
The embodiment of a kind of multi-channel DC high pressure of the utility model sample circuit, as shown in Figure 1, comprise: bus to be sampled, be serially connected with pressure sampling circuit between the positive bus-bar of described bus and negative busbar, described pressure sampling circuit comprises positive bus-bar and the divider resistance R1 between negative busbar and the divider resistance R2 that is serially connected with successively bus, and the tie point of described divider resistance R1 and divider resistance R2 is output terminal.Realize the purpose of dividing potential drop sampling in the simplest mode.Certainly also can be between the positive bus-bar of bus and negative busbar the more electron device of series and parallel to realize dividing potential drop sampling purpose.Also comprise A/D change-over circuit 1, optical coupling isolation circuit 2 and signal processing unit 3, the output terminal of described pressure sampling circuit connects the input end of A/D change-over circuit 1, the output terminal of described A/D change-over circuit 1 connects the input end of optical coupling isolation circuit, and the output terminal of described optical coupling isolation circuit connects signal processing unit 3.
In sampling process, pressure sampling circuit transfers the high pressure between tested bus to low voltage signal, then directly this low-voltage signal being transferred to A/D change-over circuit 1 changes, transfer this simulating signal to digital signal, and then signal is processed through delivering to signal processing unit 3 after optical coupling isolation circuit 2.Therefore, for a sampled signal only through three necessary links: be used for obtaining low-voltage signal the dividing potential drop sampling element, analog-signal transitions is the A/D conversion links of digital signal and the electrical isolation that is used for realizing main circuit and signal processing unit 3, improves the light-coupled isolation link of system rejection to disturbance ability and reliability.Compared with prior art, the utility model is because the small-signal that directly will easily be disturbed carries out the A/D conversion, therefore need not filtering, amplification etc. to the intermediate treatment link of signal, reduce to greatest extent the possible interference that is subject to and the decay of signal (small-signal that particularly easily is disturbed), improved sampling precision.
Simultaneously, need not to adopt again the built-in A/D converter of CPU in signal processing unit 3 in the utility model, avoided the built-in A/D converter of CPU, avoid conversion accuracy restricted, greatly improve the precision of A/D conversion.
As shown in Figure 3, described A/D change-over circuit 1 comprises analog to digital converter ADS1118.These 16 analog to digital converters are compared 10 A/D conversion accuracies that CPU carries and are greatly improved, and temperature drift is low, and power consumption is little, can support high-frequency sampling, and ADS1118 can be multiplexed simultaneously, facilitate image data in the multiple signal that different sensors provides.Such as, can with ADS1118 wherein one the tunnel as voltage signal acquisition, and with another road as the current signal collection.
As shown in Figure 5, described optical coupling isolation circuit 2 adopts 6N137 type optocoupler, because sampled signal is first changed through A/D, the signal antijamming capability improves greatly, requirement to light-coupled isolation reduces greatly, therefore adopt this optocoupler can satisfy insulation request, this optocoupler is cheap simultaneously, effectively reduces the overall cost of circuit.
As shown in Figure 1, in the present embodiment, comprise N road bus to be sampled, N photoelectric relay (S1, S2 are arranged ... SN) be arranged at respectively between pressure sampling circuit and A/D change-over circuit 1 on the bus of every road, as shown in Figure 2.And for example shown in Figure 4, described signal processing unit 3 output terminals are connected with the multi-channel sampling control circuit that is made of chip 74HC595, and the multi-channel sampling control circuit is according to control signal (VS1, the VS2 of signal processing unit 3 outputs ... VSN) control respectively a plurality of photoelectric relays (S1, S2 ... SN) conduction and cut-off.In sampling process, N photoelectric relay S1 and S2 only have a conducting, for example when photoelectric relay S1 conducting, other photoelectric relays (S2, S3 ... SN) cut-off, this moment, A/D change-over circuit 1 obtained the voltage signal that the pressure sampling circuit that is connected with photoelectric relay S1 obtains, and this voltage signal is carried out A/D change and flow to signal processing unit 3 by light-coupled isolation.In like manner, when photoelectric relay S2 conducting, other photoelectric relays (S1, S3 ... SN) cut-off, this moment, A/D change-over circuit 1 obtained the voltage signal that the pressure sampling circuit that is connected with photoelectric relay S2 obtains, and this voltage signal is carried out A/D change and flow to signal processing unit 3 by light-coupled isolation.Therefore in sampling process, signal processing unit 3 only obtains the signal of one road bus all the time, and signal processing unit 3 only need provide an I/O interface.Avoid the situation that the I/O end is not enough to use in the multi-channel sampling process, saved the I/O interface resource, be beneficial to signal processing unit 3 and carry out Function Extension.
Certainly, also can suitably adjust according to available I/O interface resource the conducting quantity of photoelectric relay in sampling process, only need suitably to expand multi-channel sampling control circuit and A/D change-over circuit 1 and adjust control strategy to get final product.
Should be noted that at last; above embodiment is only in order to illustrate the technical solution of the utility model; but not to the restriction of the utility model protection domain; although with reference to preferred embodiment, the utility model has been done to explain; those of ordinary skill in the art is to be understood that; can modify or be equal to replacement the technical solution of the utility model, and not break away from essence and the scope of technical solutions of the utility model.
Claims (7)
1. a high direct voltage is isolated sample circuit, comprise between the positive bus-bar that is arranged at bus to be sampled and negative busbar and be serially connected with pressure sampling circuit, also comprise A/D change-over circuit, optical coupling isolation circuit and signal processing unit, it is characterized in that: the output terminal of described pressure sampling circuit connects the input end of A/D change-over circuit, the output terminal of described A/D change-over circuit connects the input end of optical coupling isolation circuit, and the output terminal of described optical coupling isolation circuit connects signal processing unit.
2. a kind of high direct voltage as claimed in claim 1 is isolated sample circuit, it is characterized in that: bus quantity described to be sampled is no less than two-way, is respectively arranged with between the pressure sampling circuit on each road bus and A/D change-over circuit to be controlled by signal processing unit the switch of its conduction and cut-off.
3. a kind of high direct voltage as claimed in claim 2 is isolated sample circuit, and it is characterized in that: described a plurality of switches have a switch conduction at the most in sampling process.
4. a kind of high direct voltage as claimed in claim 2 is isolated sample circuit, and it is characterized in that: described switch is photoelectric relay.
5. a kind of high direct voltage isolation sample circuit as claimed in claim 2 is characterized in that: described signal processing unit by the multi-channel sampling control circuit to control the conduction and cut-off of each switch.
6. a kind of high direct voltage as claimed in claim 1 is isolated sample circuit, it is characterized in that: described pressure sampling circuit comprises positive bus-bar and the divider resistance R1 between negative busbar and the divider resistance R2 that is serially connected with successively bus, and the tie point of described divider resistance R1 and divider resistance R2 is as the output terminal of pressure sampling circuit.
7. a kind of high direct voltage as claimed in claim 1 is isolated sample circuit, and it is characterized in that: described A/D change-over circuit comprises analog to digital converter ADS1118.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220562820 CN203011986U (en) | 2012-10-30 | 2012-10-30 | Direct-current high-voltage isolation sampling circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220562820 CN203011986U (en) | 2012-10-30 | 2012-10-30 | Direct-current high-voltage isolation sampling circuit |
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| Publication Number | Publication Date |
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| CN203011986U true CN203011986U (en) | 2013-06-19 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201220562820 Expired - Lifetime CN203011986U (en) | 2012-10-30 | 2012-10-30 | Direct-current high-voltage isolation sampling circuit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102998512A (en) * | 2012-10-30 | 2013-03-27 | 广东易事特电源股份有限公司 | Direct-current high-voltage isolation sampling circuit |
| CN104635175A (en) * | 2013-11-13 | 2015-05-20 | 中国科学院沈阳计算技术研究所有限公司 | High-voltage direct current monitoring system and monitoring method thereof |
| CN110007126A (en) * | 2019-04-17 | 2019-07-12 | 电子科技大学 | A kind of isolation detection circuit of DC bus voltage |
-
2012
- 2012-10-30 CN CN 201220562820 patent/CN203011986U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102998512A (en) * | 2012-10-30 | 2013-03-27 | 广东易事特电源股份有限公司 | Direct-current high-voltage isolation sampling circuit |
| CN102998512B (en) * | 2012-10-30 | 2015-08-19 | 广东易事特电源股份有限公司 | A kind of high direct voltage isolation sample circuit |
| CN104635175A (en) * | 2013-11-13 | 2015-05-20 | 中国科学院沈阳计算技术研究所有限公司 | High-voltage direct current monitoring system and monitoring method thereof |
| CN110007126A (en) * | 2019-04-17 | 2019-07-12 | 电子科技大学 | A kind of isolation detection circuit of DC bus voltage |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130619 |