CN103941791A - A circuit for reference ground connection conversion - Google Patents
A circuit for reference ground connection conversion Download PDFInfo
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- CN103941791A CN103941791A CN201310016497.1A CN201310016497A CN103941791A CN 103941791 A CN103941791 A CN 103941791A CN 201310016497 A CN201310016497 A CN 201310016497A CN 103941791 A CN103941791 A CN 103941791A
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Abstract
The invention provides a circuit for reference ground connection conversion, the circuit comprising: an operational amplifier, first and second crystal triodes, a sampling resistor, a control end resistor, and first, second, third and fourth resistors, one end of the sampling resistor is connected to the anode of the operational amplifier, the other end of the sampling resistor is connected to the negative terminal of the operational amplifier through the first resistor, the negative terminal of the operational amplifier is connected to the output end of the operational amplifier through the second resistor, the output end of the operational amplifier is connected to the emitting electrode of the first crystal triode, the base electrode of the first crystal triode is connected to the collecting electrode of the first crystal triode, the collecting electrode of the first crystal triode is connected to the ground through the third resistor, the collecting electrode of the first crystal triode is also connected to the base electrode of the second crystal triode, the emitting electrode of the second crystal triode is connected to the anode of the operational amplifier through the fourth resistor, the collecting electrode of the second crystal triode is connected to the ground through the control end resistor, and the first and second crystal triodes are of the same type.
Description
Technical field
The present invention relates to circuit engineering field, especially relate to one with reference to the circuit of ground connection conversion.
Background technology
In order to reach the object of controlling output, need to be by the signal of output, for example voltage or electric current, feed back to control circuit.Because the power supply of a lot of control circuits is all provided by input power, so the ground connection of the signal that output feeds back. must be consistent with control signal.Under many circumstances, switching power circuit particularly, output is inconsistent with the ground of input, thereby usually adopts the technology of isolation to carry out the conversion with reference to ground connection.What Fig. 1 showed is the flyback operating circuit by transformer isolation.Ground on the both sides of transformer is different.When former limit at transformer of the working power of control section, and control circuit is as signal amplifier, multiplier, and comparer, and drive equipment, all by same working power, driven, so their reference ground connection is the same.But the sampled signal of output terminal, as the voltage drop that output current produces on sampling resistor, has different reference ground connection.Because isolate completely on this Bian Hefu limit, circuit Central Plains, so pay any point on limit, can join with the ground connection of input end.For example,, as output current gone with regulation output electric current at the signal feedback on sampling resistor to the control circuit on former limit, the point between diode and sampling resistor can be connected to the ground connection on former limit.
Isolation technology can be grounded conversion, but circuit volume is larger, and power attenuation is also larger, and the requirement of circuit design is very high, so cost is also corresponding higher.
Summary of the invention
The technical matters that the present invention solves is that solution isolates by no means the signal ground conversion that circuit of reversed excitation is falling-rising volt circuit, make the circuit of the different ground connection of non-isolation control and become likely, and because circuit is for this reason the little current circuit of low-voltage, be easy to be integrated, can greatly simplify circuit.
In order to overcome the above problems, the invention provides one with reference to the circuit of ground connection conversion, comprise: operational amplifier, first crystal triode, the second transistor, sampling resistor, control end resistance, the first resistance, the second resistance, the 3rd resistance and the 4th resistance, described sampling resistor one end concatenation operation amplifier anode, the sampling resistor other end is by the first resistance concatenation operation amplifier negative terminal, operational amplifier negative terminal is by the second resistance concatenation operation amplifier out, operational amplifier output terminal is connected with the emitting stage of first crystal triode, the ground level of first crystal triode is connected with the collector of first crystal triode, the collector of first crystal triode is by the 3rd resistance eutral grounding, and be connected with the ground level of the second transistor, the second transistor emitting stage is connected by the 4th resistance and operational amplifier are anodal, the second transistor current collection level is by control end resistance eutral grounding, described first crystal triode, the second transistor is transistor of the same type.
Further, as preferably, the bleeder circuit consisting of the 5th, the 6th resistance and the 7th, the 8th resistance respectively at described sampling resistor two ends is connected with the first resistance with operational amplifier is anodal, and the ratio of dividing potential drop is identical.
Further, as preferably, after the bleeder circuit of described the 5th, the 6th resistance and the 7th, the 8th resistance composition, be connected to respectively the first impact damper and the second impact damper.
The present invention by circuit conversion, makes the circuit of the different ground connection of non-isolation control and become likely, and because circuit is for this reason the little current circuit of low-voltage, is easy to be integrated, and can greatly simplify circuit.
Accompanying drawing explanation
When considered in conjunction with the accompanying drawings, by the detailed description with reference to below, can more completely understand better the present invention and easily learn wherein many advantages of following, accompanying drawing described herein is used to provide a further understanding of the present invention, form a part of the present invention, schematic description and description of the present invention is used for explaining the present invention, does not form inappropriate limitation of the present invention, wherein:
Fig. 1 is the existing circuit diagram with isolation technology conversion ground connection.
Fig. 2 is that the non-isolation of inventive embodiments is with reference to the circuit diagram of ground connection conversion.
Embodiment
Referring to figure, embodiments of the invention are described.
For above-mentioned purpose, feature and advantage can be become apparent more, below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation.
As shown in Figure 2, input voltage vin is through bias voltage 101, deliver on resistance 102, after diode 102 and electric capacity 105 rectifications, on sampling resistor 106, form voltage, a circuit with reference to ground connection conversion, comprise: operational amplifier 123, first crystal triode 114, the second transistor 110, sampling resistor 106, control end resistance 112, the first resistance 124, the second resistance 122, the 3rd resistance 113 and the 4th resistance 115, described sampling resistor 106 one end concatenation operation amplifier 123 positive poles, sampling resistor 106 other ends are by the first resistance 124 concatenation operation amplifier 123 negative terminals, operational amplifier 123 negative terminals are by the second resistance 122 concatenation operation amplifier 123 output terminals, operational amplifier 123 output terminals are connected with the emitting stage of first crystal triode 114, the ground level of first crystal triode 114 is connected with the collector of first crystal triode 114, the collector of first crystal triode 114 is by the 3rd resistance 113 ground connection, and be connected with the ground level of the second transistor 110, the second transistor 110 emitting stages are connected with operational amplifier 123 is anodal by the 4th resistance 115, the second transistor 110 current collection levels are by control end resistance 112 ground connection, described first crystal triode 114, the second transistor 110 is transistor of the same type.At described sampling resistor 106 two ends, by the 5th resistance 117, the 6th resistance 120 and the bleeder circuit that the 7th resistance 118, the 8th resistance 119 form, be connected with the first resistance 124 with operational amplifier 123 is anodal respectively.After the bleeder circuit forming at described the 5th resistance 117, the 6th resistance 120 and the 7th resistance 118, the 8th resistance 119, be connected to respectively the first impact damper 111 and the second impact damper 125.First crystal triode 114, the second transistor 110 are PNP transistor.
The invention enables circuit just need not isolate and can access feedback signal, thereby output is controlled.Fig. 2 is falling-rising volt circuit, and its essence is exactly the flyback operating circuit of not isolating.Therefore, as the output signal on the output current sampling resistor 106 in Fig. 2 being used for controlling, take between diode 104 and sampling resistor 106 is ground connection, and this ground connection must be transformed into the ground connection identical with control circuit, so this ground connection needs conversion.Both end voltage on output current sampling resistor 106 is all adjusted controlling the ground connection of power supply, in Fig. 2, be to the 5th resistance 117 and the 6th resistance 120 by divider resistance, and the 7th resistance 118 and the 8th resistance 119 carry out step-down, the ratio of its dividing potential drop is identical.The impact on signal with elimination subsequent conditioning circuit by the first impact damper 111 and the second impact damper 125 respectively of both end voltage after step-down.Then these two signals are admitted to operational amplifier 123 its difference are carried out to signal amplification.And the second resistance 122 and the 1 can regulate enlargement factor.Operational amplifier 123 is output as with reference to control circuit ground connection, adds the DC offset voltage of operational amplifier 123 through the current signal amplifying.Therefore as long as bias voltage is eliminated, what obtain is exactly the output current signal with reference to control circuit ground connection.The method of eliminating is exactly that the output signal of operational amplifier 123 and DC offset voltage are subtracted each other.The pressure drop of the diode that the output of operational amplifier 123 consists of first crystal triode 114, at the 3rd resistance 113, guarantee under the condition of the second transistor 110 conductings, base stage by the second transistor 110 is boosted to the diode of emitter again, the output of result operational amplifier 123, be output current signal and add that DC offset voltage does not have increase not reduce the one end that arrives the 4th resistance 115 yet, the identical DC offset voltage that comes from the first impact damper 111 outputs has arrived the other end.Therefore the DC offset voltage on the 4th resistance 115 is offset, and its voltage difference is output signal.The electric current that this pressure reduction produces on the 4th resistance 115 has represented the signal of output.And this electric current flows through control end resistance 112 and becomes with reference to the ground connection output current feedback signal identical with control system, can be used for reaching the object of regulation and control output.
As mentioned above, embodiments of the invention are explained, but as long as not departing from fact inventive point of the present invention and effect can have a lot of distortion, this will be readily apparent to persons skilled in the art.Therefore, within such variation is also all included in protection scope of the present invention.
Claims (4)
1. a circuit with reference to ground connection conversion, it is characterized in that, comprise: operational amplifier, first crystal triode, the second transistor, sampling resistor, control end resistance, the first resistance, the second resistance, the 3rd resistance and the 4th resistance, described sampling resistor one end concatenation operation amplifier anode, the sampling resistor other end is by the first resistance concatenation operation amplifier negative terminal, operational amplifier negative terminal is by the second resistance concatenation operation amplifier out, operational amplifier output terminal is connected with the emitting stage of first crystal triode, the ground level of first crystal triode is connected with the collector of first crystal triode, the collector of first crystal triode is by the 3rd resistance eutral grounding, and be connected with the ground level of the second transistor, the second transistor emitting stage is connected by the 4th resistance and operational amplifier are anodal, the second transistor current collection level is by control end resistance eutral grounding, described first crystal triode, the second transistor is transistor of the same type.
2. a circuit with reference to ground connection conversion as claimed in claim 1, it is characterized in that, the bleeder circuit consisting of with the 7th, the 8th resistance the 5th, the 6th resistance respectively at described sampling resistor two ends is connected with the first resistance with operational amplifier is anodal, and the ratio of dividing potential drop is identical.
3. a circuit with reference to ground connection conversion as claimed in claim 2, is characterized in that, is respectively connected to first impact damper and second impact damper after the bleeder circuit forming at described the 5th, the 6th resistance and the 7th, the 8th resistance.
4. a circuit with reference to ground connection conversion as claimed in claim 1, is characterized in that, described first crystal triode, the second transistor are PNP transistor.
Priority Applications (1)
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CN201310016497.1A CN103941791A (en) | 2013-01-17 | 2013-01-17 | A circuit for reference ground connection conversion |
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CN201310016497.1A CN103941791A (en) | 2013-01-17 | 2013-01-17 | A circuit for reference ground connection conversion |
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CN201310016497.1A Pending CN103941791A (en) | 2013-01-17 | 2013-01-17 | A circuit for reference ground connection conversion |
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6307758B1 (en) * | 2000-11-02 | 2001-10-23 | Motorola, Inc. | Transformer secondary disconnect |
JP2003098215A (en) * | 2001-09-26 | 2003-04-03 | Canon Inc | Earth detection method and device in power conversion system |
CN101064469A (en) * | 2006-04-29 | 2007-10-31 | 硕颉科技股份有限公司 | DC-DC power supply converter |
JP2012005224A (en) * | 2010-06-16 | 2012-01-05 | Yokogawa Electric Corp | Insulated power supply device |
CN102468761A (en) * | 2010-11-16 | 2012-05-23 | 海洋王照明科技股份有限公司 | Switch power supply |
CN102522978A (en) * | 2012-01-06 | 2012-06-27 | 河南华南医电科技有限公司 | Isolation type power transistor driver |
-
2013
- 2013-01-17 CN CN201310016497.1A patent/CN103941791A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6307758B1 (en) * | 2000-11-02 | 2001-10-23 | Motorola, Inc. | Transformer secondary disconnect |
JP2003098215A (en) * | 2001-09-26 | 2003-04-03 | Canon Inc | Earth detection method and device in power conversion system |
CN101064469A (en) * | 2006-04-29 | 2007-10-31 | 硕颉科技股份有限公司 | DC-DC power supply converter |
JP2012005224A (en) * | 2010-06-16 | 2012-01-05 | Yokogawa Electric Corp | Insulated power supply device |
CN102468761A (en) * | 2010-11-16 | 2012-05-23 | 海洋王照明科技股份有限公司 | Switch power supply |
CN102522978A (en) * | 2012-01-06 | 2012-06-27 | 河南华南医电科技有限公司 | Isolation type power transistor driver |
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Effective date of abandoning: 20170301 |