Voltage isolation circuit and power supply device
By using a series structure of transformer and optocoupler and a voltage regulator circuit, the problem of insufficient voltage withstand capability of optocoupler was solved, thereby improving the voltage withstand capability of voltage isolation circuit and reducing cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN ANKEXUCHUANG TECHNOLOGY CO LTD
- Filing Date
- 2025-04-25
- Publication Date
- 2026-05-15
AI Technical Summary
In existing technologies, the withstand voltage of optocouplers is typically 5 kV, which is difficult to increase to 10 kV or higher, and the cost is also high.
A transformer and multiple optocouplers are connected in series. The output winding of the transformer isolates the optocouplers. Combined with a voltage regulator circuit and capacitors, voltage isolation is achieved, thereby improving the withstand voltage of the voltage isolation circuit.
This achieves a voltage withstand voltage of more than twice that of a single optocoupler, reducing costs and improving the reliability of electrical isolation.
Smart Images
Figure CN224249688U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic power technology, and in particular to voltage isolation circuits and power supply devices. Background Technology
[0002] In existing technologies, optocouplers are typically used to isolate two circuits that require electrical isolation.
[0003] The drawback of existing technology is that, due to limitations in processes and materials, the withstand voltage of optocouplers made of commonly used materials is usually 5 kV. If the withstand voltage of optocouplers needs to be increased to 10 kV or above, higher quality insulating materials and higher voltage-resistant semiconductor materials are required to construct the optocouplers, which usually results in higher costs. Furthermore, the maximum withstand voltage that optocouplers can achieve is still relatively low. Utility Model Content
[0004] The main technical problem addressed in this application is how to improve the withstand voltage of voltage isolation circuits.
[0005] To solve the aforementioned technical problems, the first technical solution adopted in this application is: a voltage isolation circuit, including a transformer, at least one first optocoupler, and at least one second optocoupler; the input terminal of the input winding of the transformer is used to receive a power supply voltage; the positive output terminal of the first output winding of the transformer is connected to the first output terminal of the second optocoupler, the negative output terminal of the first output winding of the transformer is connected to the negative input terminal of the first optocoupler, and the second output terminal of the second optocoupler is connected to the positive input terminal of the first optocoupler; the first and second output terminals of the first optocoupler are used to connect to an external first signal circuit; the positive and negative input terminals of the second optocoupler are used to connect to an external second signal circuit.
[0006] The voltage isolation circuit further includes at least one third optocoupler. The first, second, and third optocouplers are connected in series. The transformer also has at least one second output winding. Between adjacent second and third optocouplers, the positive output terminal of the second output winding is connected to the first output terminal of the third optocoupler, the negative output terminal of the second output winding is connected to the negative input terminal of the second optocoupler, and the second output terminal of the third optocoupler is connected to the positive input terminal of the second optocoupler. The positive and negative input terminals of the third optocoupler are used to connect to an external second signal circuit.
[0007] The voltage isolation circuit also includes a first voltage regulator circuit; the first voltage regulator circuit is connected to the positive output terminal of the first output winding, the negative output terminal of the first output winding, the first output terminal of the second optocoupler, and the negative input terminal of the first optocoupler; the first voltage regulator circuit is used to regulate the voltage output by the first output winding.
[0008] The voltage isolation circuit also includes a first capacitor; one end of the first capacitor is connected to the positive output terminal of the first output winding and the input terminal of the first voltage regulator circuit, and the other end of the first capacitor is connected to the negative output terminal of the first output winding and the ground terminal of the first voltage regulator circuit, the output terminal of the first voltage regulator circuit is connected to the first output terminal of the second optocoupler, and the ground terminal of the first voltage regulator circuit is connected to the negative input terminal of the first optocoupler.
[0009] The voltage isolation circuit also includes a second capacitor; one end of the second capacitor is connected to the output terminal of the first voltage regulator circuit and the first output terminal of the second optocoupler, respectively, and the other end of the second capacitor is connected to the ground terminal of the first voltage regulator circuit and the negative input terminal of the first optocoupler, respectively.
[0010] The voltage isolation circuit also includes a current-limiting resistor; the current-limiting resistor is set in the loop formed by the second capacitor, the second optocoupler and the first optocoupler.
[0011] The voltage isolation circuit further includes a first voltage regulator circuit and a second voltage regulator circuit. The first voltage regulator circuit is connected to the positive output terminal of the first output winding, the negative output terminal of the first output winding, the first output terminal of the second optocoupler, and the negative input terminal of the first optocoupler, respectively, and is used to regulate the voltage output by the first output winding. The second voltage regulator circuit is connected to the positive output terminal of the second output winding, the negative output terminal of the second output winding, the first output terminal of the third optocoupler, and the negative input terminal of the second optocoupler, respectively, and is used to regulate the voltage output by the second output winding.
[0012] The total number of the first, second, and third optocouplers is the number of optocouplers; the withstand voltage of the transformer is a multiple of the target number of the optocoupler withstand voltages, and the target number is one less than the number of optocouplers.
[0013] The first or second voltage regulator circuit includes a transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, and a Zener diode. One end of the first resistor is used to receive a first voltage, and the other end of the first resistor is connected to one end of the second resistor and the first end of the transistor. The second end of the transistor is used to receive a second voltage, and the second end of the transistor is connected to one end of the third resistor. The other end of the third resistor is connected to one end of the fourth resistor and the adjustment terminal of the Zener diode. The cathode of the Zener diode is connected to the other end of the second resistor and the driving terminal of the transistor. The anode of the Zener diode and the other end of the fourth resistor are both grounded.
[0014] To solve the above-mentioned technical problems, the second technical solution adopted in this application is: a power supply device, including a first signal circuit, a second signal circuit and the voltage isolation circuit mentioned above, wherein the voltage isolation circuit is connected to the first signal circuit and the second signal circuit respectively, and the voltage isolation circuit is used to electrically isolate the first signal circuit and the second signal circuit.
[0015] The beneficial effects of this application are as follows: Unlike existing technologies, the technical solution of this application allows the first output winding of the transformer to provide a voltage for emitting light to the LED corresponding to the negative input terminal of the first optocoupler. Furthermore, the first output winding is connected to the first output terminal of the second optocoupler, and the second output terminal of the second optocoupler is connected to the positive input terminal of the first optocoupler. This achieves isolation between the first and second optocouplers through the first output winding of the transformer. Based on this method, the transformer can withstand a voltage greater than or equal to the withstand voltage of a single optocoupler, ensuring that the voltage between the two ends of each optocoupler does not exceed its self-voltage limit. The withstand voltage of the voltage isolation circuit is increased so that the voltage between the second optocoupler and the transformer is not greater than the withstand voltage of the second optocoupler, and the voltage between the first optocoupler and the transformer is not greater than the withstand voltage of the first optocoupler. This allows the voltage isolation circuit to operate normally, thereby enabling the total withstand voltage of the voltage isolation circuit to reach the sum of the withstand voltages of the second optocoupler and the first optocoupler. This avoids the situation where the voltage isolation circuit is limited to the withstand voltage of a single optocoupler. It can electrically isolate two signal circuits that require electrical isolation when the voltage difference is greater than the withstand voltage of a single optocoupler. In summary, the withstand voltage of the voltage isolation circuit is improved. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of one embodiment of the voltage isolation circuit of this application;
[0018] Figure 2 This is a schematic diagram of the structure of one embodiment of the voltage isolation circuit of this application;
[0019] Figure 3 This is a schematic diagram of the structure of one embodiment of the power supply device of this application;
[0020] Figure 4 This is a schematic diagram of an embodiment of the first voltage regulator circuit of this application.
[0021] The attached figures are labeled as follows: 101, transformer; 1011, first output winding; 1012, second output winding; 102, first optocoupler; 103, second optocoupler; 104, third optocoupler; 105, first voltage regulator circuit; 1051, first resistor; 1052, second resistor; 1053, third resistor; 1054, fourth resistor; 1055, transistor; 1056, Zener diode; 106, second voltage regulator circuit; 107, first capacitor; 108, second capacitor; 109, current-limiting resistor; 10, voltage isolation circuit; 20, first signal circuit; 30, second signal circuit. Detailed Implementation
[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0023] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.
[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0025] This application proposes a voltage isolation circuit, see [link to relevant documentation] Figure 1 , Figure 1 This is a schematic diagram of one embodiment of the voltage isolation circuit of this application, as shown below. Figure 1 As shown, the voltage isolation circuit includes a transformer 101, at least one first optocoupler 102 and at least one second optocoupler 103.
[0026] The input terminal of the input winding of transformer 101 is used to receive the power supply voltage.
[0027] The positive output terminal of the first output winding 1011 of transformer 101 is connected to the first output terminal of the second optocoupler 103, the negative output terminal of the first output winding 1011 of transformer 101 is connected to the negative input terminal of the first optocoupler 102, and the second output terminal of the second optocoupler 103 is connected to the positive input terminal of the first optocoupler 102.
[0028] The first output terminal and the second output terminal of the first optocoupler 102 are used to connect to the external first signal circuit 20, and the positive input terminal and the negative input terminal of the second optocoupler 103 are used to connect to the external second signal circuit 30.
[0029] Specifically, both the first optocoupler 102 and the second optocoupler 103 are optocouplers. An optocoupler may include a phototransistor and a light-emitting diode. The negative input terminal of the optocoupler may be the negative terminal of the light-emitting diode, and the positive input terminal of the optocoupler may be the positive terminal of the light-emitting diode. The first output terminal of the optocoupler is the first output terminal of the phototransistor, and the second output terminal of the optocoupler is the second output terminal of the phototransistor.
[0030] The transformer 101 may have multiple output windings for output voltage, such as a first output winding 1011. The first output winding 1011 can output a voltage to power the light-emitting diode at the input terminal of the optocoupler. When the light-emitting diode at the input terminal of the second optocoupler 103 is lit, the first output terminal and the second output terminal of the second optocoupler 103 are connected. Then, the voltage provided by the first output winding 1011 causes the light-emitting diode at the input terminal of the first optocoupler 102 to light, so that the first output terminal and the second output terminal of the first optocoupler 102 are connected, thereby forming a circuit at the output terminal of the first optocoupler 102. That is, based on the above method, when the circuit at the input terminal of the second optocoupler 103 is formed, the power supply to the first optocoupler 102 by the first output winding 1011 of the transformer 101 can also form a circuit at the output terminal of the first optocoupler 102.
[0031] The voltage between the positive and negative output terminals of the first output winding 1011 is less than or equal to the withstand voltage of the light-emitting diode (LED) of the first optocoupler 102. That is, in the above process, the voltage between the positive and negative output terminals of the first output winding 1011 can be a voltage that allows the LED in the optocoupler to emit light without being damaged. Specifically, it can be any value among 3 volts, 5 volts, 10 volts, and other values, and this value is typically much smaller than the withstand voltage of the optocoupler.
[0032] By ensuring that the potential of the first output winding 1011 of transformer 101 reaches the withstand voltage of a single optocoupler, and by ensuring that the voltage between the negative output terminal of the first output winding 1011 of transformer 101 and the first or second output terminal of the first optocoupler 102 can reach the withstand voltage of the first optocoupler 102, and by ensuring that the voltage between the positive output terminal of the first output winding 1011 of transformer 101 and the input terminal of the second optocoupler 103 can reach the withstand voltage of the second optocoupler 103, a circuit structure is formed in which the transformer 101 withstands a higher potential voltage to ensure that the voltage borne by each optocoupler does not exceed its own withstand voltage. Although this method requires a high withstand voltage of transformer 101, the withstand voltage of transformer 101 can be increased relatively simply and at low cost by increasing the number of turns or other methods. This increase can be several times higher than the withstand voltage of a single optocoupler. Therefore, based on the above method, the circuit structure of this voltage isolation circuit can achieve a withstand voltage at least twice that of a single optocoupler. In other words, the withstand voltage of the voltage isolation circuit is increased, so that the voltage isolation circuit can be used for electrical isolation of two circuits with a voltage difference greater than the withstand voltage of a single optocoupler. It can also improve the reliability of the signal circuit at a low cost.
[0033] Unlike existing technologies, the technical solution of this application provides a voltage for emitting light to the LED corresponding to the negative input terminal of the first optocoupler through the first output winding of the transformer. The first output winding is also connected to the first output terminal of the second optocoupler, and the second output terminal of the second optocoupler is connected to the positive input terminal of the first optocoupler. This achieves isolation between the first and second optocouplers through the first output winding of the transformer. Based on this method, the transformer can withstand a voltage greater than or equal to the withstand voltage of a single optocoupler, ensuring that the voltage between the two ends of each optocoupler does not exceed its own withstand voltage. In other words, the voltage isolation circuit can operate normally when the voltage between the second optocoupler and the transformer is not greater than the withstand voltage of the second optocoupler, and when the voltage between the first optocoupler and the transformer is not greater than the withstand voltage of the first optocoupler. This allows the total withstand voltage of the voltage isolation circuit to reach the sum of the withstand voltages of the second and first optocouplers, avoiding the situation where the voltage isolation circuit is limited to the withstand voltage of a single optocoupler. It can electrically isolate two signal circuits that require electrical isolation when the voltage difference is greater than the withstand voltage of a single optocoupler. In summary, the withstand voltage of the voltage isolation circuit is improved.
[0034] In one embodiment, see Figure 2 , Figure 2 This is a schematic diagram of one embodiment of the voltage isolation circuit of this application, as shown below. Figure 2 As shown, the voltage isolation circuit 10 also includes at least one third optocoupler 104, and the first optocoupler 102, the second optocoupler 103 and the third optocoupler 104 are connected in series. The transformer 101 also has at least one second output winding 1012.
[0035] Between the adjacent second optocoupler 103 and third optocoupler 104, the positive output terminal of the second output winding 1012 is connected to the first output terminal of the third optocoupler 104, the negative output terminal of the second output winding 1012 is connected to the negative input terminal of the second optocoupler 103, and the second output terminal of the third optocoupler 104 is connected to the positive input terminal of the second optocoupler 103.
[0036] It can be understood that when the positive and negative input terminals of the second optocoupler 103 are connected to the third optocoupler, the positive and negative input terminals of the third optocoupler 104 are used to connect to the external second signal circuit 30.
[0037] The first output winding 1011 and the second output winding 1012 are independent output windings.
[0038] Specifically, taking a voltage isolation circuit including a third optocoupler 104 as an example, the positive output terminal of the second output winding 1012 of transformer 101 is connected to the first output terminal of the third optocoupler 104, the negative output terminal of the second output winding 1012 of transformer 101 is connected to the negative input terminal of the second optocoupler 103, and the second output terminal of the third optocoupler 104 is connected to the positive input terminal of the second optocoupler 103. The first output winding 1011 and the second output winding 1012 are independent output windings.
[0039] The transformer 101 has multiple output windings for outputting voltage, which may also include a second output winding 1012. The second output winding 1012 can output a voltage to power the light-emitting diode at the input terminal of the optocoupler. When the light-emitting diode at the input terminal of the third optocoupler 104 is lit, the first output terminal and the second output terminal of the third optocoupler 104 are connected. Then, the voltage provided by the second output winding 1012 causes the light-emitting diode at the input terminal of the second optocoupler 103 to light, so that the first output terminal and the second output terminal of the second optocoupler 103 are connected, thereby forming a circuit at the output terminal of the second optocoupler 103. That is, based on the above method, when the circuit at the input terminal of the third optocoupler 104 is formed into a circuit, the power supply to the second optocoupler 103 by the second output winding 1012 of the transformer 101 can also form a circuit at the output terminal of the second optocoupler 103.
[0040] Subsequently, when the circuit at the input terminal of the second optocoupler 103 forms a loop, the LED at the input terminal of the second optocoupler 103 emits light, and the first output terminal and the second output terminal of the second optocoupler 103 are connected. Then, the voltage provided by the first output winding 1011 causes the LED at the input terminal of the first optocoupler 102 to emit light, causing the first output terminal and the second output terminal of the first optocoupler 102 to be connected, thereby forming a loop at the output terminal of the first optocoupler 102. That is, based on the above method, when the circuit at the input terminal of the second optocoupler 103 forms a loop, the power supply to the first optocoupler 102 by the first output winding 1011 of the transformer 101 can also form a loop at the output terminal of the first optocoupler 102.
[0041] In summary, based on this voltage isolation circuit, when the circuit at the input terminal of the third optocoupler 104 forms a loop, the power supply to the corresponding optocoupler is provided by the output windings of the transformer 101, ultimately enabling the circuit at the output terminal of the first optocoupler 102 to form a loop. This allows the circuit at the output terminal of the first optocoupler 102 to be indirectly controlled by controlling the circuit at the input terminal of the third optocoupler 104, thus achieving control of one circuit over another under electrically isolated conditions.
[0042] In the above process, the voltage between the positive output terminal and the negative output terminal of the second output winding 1012, and the voltage between the positive output terminal and the negative output terminal of the second output winding 1012, can both be voltages that enable the light-emitting diode in the optocoupler to emit light without being damaged. Specifically, it can be any value among 3 volts, 5 volts, 10 volts, and other values. This value is usually much smaller than the withstand voltage of the optocoupler.
[0043] The potential of the second output winding 1012 can reach the withstand voltage of a single optocoupler, while the potential of the first output winding 1011 can reach the withstand voltage of two optocouplers. This forms a circuit structure in which the transformer 101 withstands a higher potential voltage to ensure that the voltage across each optocoupler does not exceed its own withstand voltage. Although this method requires a higher withstand voltage of the transformer 101, the withstand voltage of the transformer 101 can be increased relatively simply and at low cost by increasing the number of turns or other methods. This increase can be several times higher than the withstand voltage of a single optocoupler. Therefore, based on the above method, the voltage isolation circuit can achieve a withstand voltage at least twice that of a single optocoupler. For example, the withstand voltage of the voltage isolation circuit containing the first optocoupler 102, the second optocoupler 103, and the third optocoupler 104 is three times that of a single optocoupler. In summary, the withstand voltage of the voltage isolation circuit can be improved.
[0044] It should be noted that the above is only one example. In other examples, the number of third optocouplers 104 can be 2, 5, 10 or any other arbitrary number, to ultimately form a voltage isolation circuit with a withstand voltage at least twice that of a single optocoupler.
[0045] Optionally, the total number of the first optocoupler 102, the second optocoupler 103 and at least one third optocoupler 104 is the number of optocouplers, and the withstand voltages corresponding to the first optocoupler 102, the second optocoupler 103 and at least one third optocoupler 104 are all the optocoupler withstand voltages.
[0046] The withstand voltage of transformer 101 is a multiple of the target withstand voltage of the optocoupler, and the target number is one less than the number of optocouplers.
[0047] For example, the withstand voltage of an optocoupler is the withstand voltage of a single optocoupler. Let's assume that the withstand voltage of a single optocoupler is 5 kV.
[0048] In the first case, such as Figure 1 As shown, when there are at least two optocouplers connected in series, and each optocoupler withstands a voltage of 5 kV, the transformer's withstand voltage needs to reach 5 kV (at this time, the output winding with the highest potential corresponds to 5 kV, so the transformer's withstand voltage needs to reach 5 kV) so that the withstand voltage of the voltage isolation circuit reaches the sum of the withstand voltages of the two optocouplers, that is, so that the withstand voltage of the voltage isolation circuit can reach 10 kV.
[0049] In the second case, such as Figure 1 As shown, when there are at least three optocouplers connected in series, and each optocoupler withstands a voltage of 5 kV, the transformer's withstand voltage needs to reach 10 kV (at this time, the output winding with the highest potential corresponds to 10 kV, so the transformer's withstand voltage needs to reach 10 kV) so that the withstand voltage of the voltage isolation circuit reaches the sum of the withstand voltages of the three optocouplers, that is, so that the withstand voltage of the voltage isolation circuit can reach 15 kV.
[0050] Based on the above method, the withstand voltage of the voltage isolation circuit can be improved compared to the traditional voltage isolation circuit, which is limited by the withstand voltage of a single optocoupler.
[0051] Furthermore, by increasing the number of optocouplers and adding more independently configured second output windings 1012 to supply power to different groups of series-connected adjacent optocouplers, the withstand voltage of the voltage isolation circuit can be continuously improved. The withstand voltage of the voltage isolation circuit will be positively correlated with the total number of optocouplers. If the theoretical maximum value of lossless and error-free operation can be reached, the positive correlation will be proportional, thus increasing the limit of the maximum value that the withstand voltage of the voltage isolation circuit can reach.
[0052] Optionally, such as Figure 2 As shown, the voltage isolation circuit may further include a first voltage regulator circuit 105 and a second voltage regulator circuit 106.
[0053] The first voltage regulator circuit 105 is connected to the positive output terminal of the first output winding 1011, the negative output terminal of the first output winding 1011, the first output terminal of the second optocoupler 103, and the negative input terminal of the first optocoupler 102, respectively. The first voltage regulator circuit 105 is used to regulate the voltage output by the first output winding 1011 so as to output the regulated voltage to the second optocoupler 103 and the first optocoupler 102.
[0054] The second voltage regulator circuit 106 is connected to the positive output terminal and the negative output terminal of the second output winding 1012, the first output terminal of the third optocoupler 104, and the negative input terminal of the second optocoupler 103, respectively. The second voltage regulator circuit 106 is used to regulate the voltage output from the second output winding 1012 to output a regulated voltage to the adjacent second optocoupler 103 and third optocoupler 104.
[0055] or,
[0056] The second voltage regulator circuit 106 is connected to the positive output terminal of the second output winding 1012, the negative output terminal of the second output winding 1012, the first output terminal of a third optocoupler 104, and the negative input terminal of another third optocoupler 104. The second voltage regulator circuit 106 is used to regulate the voltage output by the second output winding 1012 so as to output the regulated voltage to the two adjacent third optocouplers 104.
[0057] Specifically, the first voltage regulator circuit 105 and the second voltage regulator circuit 106 are both voltage regulator circuits used to regulate the voltage output by the corresponding output winding. The input terminal and ground terminal of the voltage regulator circuit are used to receive the voltage output by the corresponding output winding, and the output terminal and ground terminal of the voltage regulator circuit are used to output the regulated voltage.
[0058] The voltage regulator circuit may specifically include a linear voltage regulator chip, a voltage regulator circuit built from several transistors or Zener diodes, and at least one of other types of voltage regulator circuits with voltage regulation capability, which are not limited here.
[0059] Based on the above method, the possibility that the control of the conduction and disconnection between the first output terminal and the second output terminal of the corresponding optocoupler cannot be stably switched due to the unstable voltage output by the output winding of transformer 101 can be reduced, and the reliability of the voltage isolation circuit can be further improved.
[0060] In one embodiment, such as Figure 1 and Figure 2 As shown, the voltage isolation circuit may also include a first voltage regulator circuit 105.
[0061] The first voltage regulator circuit 105 is connected to the positive output terminal of the first output winding 1011, the negative output terminal of the first output winding 1011, the first output terminal of the second optocoupler 103, and the negative input terminal of the first optocoupler 102, respectively.
[0062] The first voltage regulator circuit 105 is used to regulate the voltage output by the first output winding 1011 so as to output the regulated voltage to the first optocoupler 102 and the second optocoupler 103.
[0063] Specifically, the first voltage regulator circuit 105 is a voltage regulator circuit used to regulate the voltage output by the corresponding output winding. The input terminal and ground terminal of the voltage regulator circuit are used to receive the voltage output by the corresponding output winding, and the output terminal and ground terminal of the voltage regulator circuit are used to output the regulated voltage.
[0064] Based on the above method, the possibility that the control of the conduction and disconnection between the first output terminal and the second output terminal of the corresponding optocoupler cannot be stably switched due to the unstable voltage output by the output winding of transformer 101 can be reduced, and the reliability of the voltage isolation circuit can be further improved.
[0065] Optionally, see Figure 4 , Figure 4 This is a schematic diagram of an embodiment of the first voltage regulator circuit of this application, as shown below. Figure 4 As shown, the first voltage regulator circuit 105 includes a first resistor 1051, a second resistor 1052, a third resistor 1053, a fourth resistor 1054, a transistor 1055, and a Zener diode 1056.
[0066] One end of the first resistor 1051 is connected to the positive output terminal of the first output winding 1011. The other end of the first resistor 1051 is connected to one end of the second resistor 1052 and the first terminal of the transistor 1055. The second end of the transistor 1055 is connected to the first output terminal of the second optocoupler 103. The second end of the transistor 1055 is connected to one end of the third resistor 1053. The other end of the third resistor 1053 is connected to one end of the fourth resistor 1054 and the adjustment terminal of the Zener diode 1056. The negative terminal of the Zener diode 1056 is connected to the other end of the second resistor 1052 and the driving terminal of the transistor 1055. The positive terminal of the Zener diode 1056 and the other end of the fourth resistor 1054 are both grounded. The negative output terminal of the first output winding 1011 and the negative input terminal of the first optocoupler 102 are connected to the other end of the fourth resistor 1054.
[0067] Specifically, one end of the first resistor 1051 can refer to the input terminal of the first voltage regulator circuit 105, the other end of the fourth resistor 1054 can refer to the ground terminal of the first voltage regulator circuit 105, and the second end of the transistor 1055 can refer to the output terminal of the first voltage regulator circuit 105.
[0068] The input terminal of the first voltage regulator circuit 105 can be used to receive the first voltage V1 output from the positive output terminal of the first output winding 1011. The input terminal of the first voltage regulator circuit 105 can be used to output the second voltage V2 obtained after the first voltage V1 is regulated to the first output terminal of the second optocoupler 103, so as to drive the light-emitting diode in the corresponding optocoupler to emit light through the second voltage V2 obtained after voltage regulation, thereby improving the stability of the connection between optocouplers.
[0069] Based on the above method, the possibility that the control of the conduction and disconnection between the first output terminal and the second output terminal of the corresponding optocoupler cannot be stably switched due to the unstable voltage output by the output winding of transformer 101 can be reduced, and the reliability of the voltage isolation circuit can be further improved.
[0070] The structure of the second voltage regulator circuit 106 mentioned in the previous embodiment may be the same as or different from that of the first voltage regulator circuit 105, and is not limited here.
[0071] Optionally, such as Figure 1 and Figure 2 As shown, the voltage isolation circuit may also include a first capacitor 107.
[0072] One end of the first capacitor 107 is connected to the positive output terminal of the first output winding 1011 and the input terminal of the first voltage regulator circuit 105, respectively. The other end of the first capacitor 107 is connected to the negative output terminal of the first output winding 1011 and the ground terminal of the first voltage regulator circuit 105, respectively. The output terminal of the first voltage regulator circuit 105 is connected to the first output terminal of the second optocoupler 103, and the ground terminal of the first voltage regulator circuit 105 is connected to the negative input terminal of the first optocoupler 102.
[0073] Specifically, the first capacitor 107 can refer to the output capacitor of the output winding coil of the first output winding 1011, which can store energy and filter the voltage output by the first output winding 1011 to initially achieve stable control of the voltage. Then, the voltage after energy storage and filtering is input into the first voltage regulator circuit 105 to achieve further voltage regulation and improve the stability of the voltage isolation circuit.
[0074] Furthermore, such as Figure 1 and Figure 2 As shown, the voltage isolation circuit may also include a second capacitor 108.
[0075] One end of the second capacitor 108 is connected to the output terminal of the first voltage regulator circuit 105 and the first output terminal of the second optocoupler 103, respectively. The other end of the second capacitor 108 is connected to the ground terminal of the first voltage regulator circuit 105 and the negative input terminal of the first optocoupler 102, respectively.
[0076] Specifically, the second capacitor 108 can refer to the output capacitor of the first voltage regulator circuit 105, which is used to store energy based on the voltage output by the first voltage regulator circuit 105, and then send it to the corresponding optocoupler to provide power, so as to realize the stable operation of the voltage isolation circuit and further improve the stability of the voltage isolation circuit.
[0077] Furthermore, such as Figure 1 and Figure 2 As shown, the voltage isolation circuit also includes a current-limiting resistor 109.
[0078] The current-limiting resistor 109 is placed in the circuit formed by the second capacitor 108, the first optocoupler 102, and the second optocoupler 103.
[0079] Specifically, the current-limiting resistor 109 can be used to adjust the current in the circuit formed by the second capacitor 108, the first optocoupler 102, and the second optocoupler 103 to achieve current limiting, thereby reducing the possibility that the current may damage the devices in the circuit formed by the second capacitor 108, the first optocoupler 102, and the second optocoupler 103, or cause the devices in the circuit formed by the second capacitor 108, the first optocoupler 102, and the second optocoupler 103 to malfunction, and further improving the stability of the voltage isolation circuit.
[0080] This application also proposes a power supply device, see [link to application]. Figure 3 , Figure 3 This is a schematic diagram of the structure of one embodiment of the power supply device of this application, as shown below. Figure 3 As shown, the power supply device includes a first signal circuit 20, a second signal circuit 30, and a voltage isolation circuit 10. The voltage isolation circuit 10 can be any of the voltage isolation circuits described in the preceding embodiments, and will not be repeated here.
[0081] The voltage isolation circuit 10 is connected to the first signal circuit 20 and the second signal circuit 30 respectively. The voltage isolation circuit 10 is used to electrically isolate the first signal circuit 20 and the second signal circuit 30. The operating voltage of the first signal circuit is lower than the operating voltage of the second signal circuit.
[0082] That is, the input terminal of the first optocoupler among all the optocouplers interconnected in the voltage isolation circuit 10 is used to connect to the first signal circuit 20, and the output terminal of the last optocoupler is used to connect to the second signal circuit 30, so as to realize the electrical isolation of the first signal circuit 20 and the second signal circuit 30 by optocoupler.
[0083] by Figure 1 and Figure 3 For example, the second optical coupler 103 is the first optical coupler, and the first optical coupler 102 is the last optical coupler, or, with Figure 2For example, the third optical coupler 104 is the first optical coupler, and the first optical coupler 102 is the last optical coupler.
[0084] Unlike existing technologies, the technical solution of this application provides a voltage for emitting light to the LED corresponding to the negative input terminal of the first optocoupler through the first output winding of the transformer. The first output winding is also connected to the first output terminal of the second optocoupler, and the second output terminal of the second optocoupler is connected to the positive input terminal of the first optocoupler. This achieves isolation between the first and second optocouplers through the first output winding of the transformer. Based on this method, the transformer can withstand a voltage greater than or equal to the withstand voltage of a single optocoupler, ensuring that the voltage between the two ends of each optocoupler does not exceed its own withstand voltage. In other words, the voltage isolation circuit can operate normally when the voltage between the second optocoupler and the transformer is not greater than the withstand voltage of the second optocoupler, and when the voltage between the first optocoupler and the transformer is not greater than the withstand voltage of the first optocoupler. This allows the total withstand voltage of the voltage isolation circuit to reach the sum of the withstand voltages of the second and first optocouplers, avoiding the situation where the voltage isolation circuit is limited to the withstand voltage of a single optocoupler. It can electrically isolate two signal circuits that require electrical isolation when the voltage difference is greater than the withstand voltage of a single optocoupler. In summary, the withstand voltage of the voltage isolation circuit is improved.
[0085] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A voltage isolation circuit, characterized in that, Includes a transformer, at least one first optocoupler, and at least one second optocoupler; The input terminal of the input winding of the transformer is used to receive the power supply voltage; The positive output terminal of the first output winding of the transformer is connected to the first output terminal of the second optocoupler, the negative output terminal of the first output winding of the transformer is connected to the negative input terminal of the first optocoupler, and the second output terminal of the second optocoupler is connected to the positive input terminal of the first optocoupler. The first output terminal and the second output terminal of the first optocoupler are used to connect to an external first signal circuit; the positive input terminal and the negative input terminal of the second optocoupler are used to connect to an external second signal circuit.
2. The voltage isolation circuit according to claim 1, characterized in that, The voltage isolation circuit further includes at least one third optocoupler, wherein the first optocoupler, the second optocoupler and the third optocoupler are connected in series, and the transformer also has at least one second output winding; Between the adjacent second optocoupler and the third optocoupler, the positive output terminal of the second output winding is connected to the first output terminal of the third optocoupler, the negative output terminal of the second output winding is connected to the negative input terminal of the second optocoupler, and the second output terminal of the third optocoupler is connected to the positive input terminal of the second optocoupler. The positive and negative input terminals of the third optocoupler are used to connect to an external second signal circuit.
3. The voltage isolation circuit according to claim 1 or 2, characterized in that, The voltage isolation circuit also includes a first voltage regulator circuit; The first voltage regulator circuit is connected to the positive output terminal of the first output winding, the negative output terminal of the first output winding, the first output terminal of the second optocoupler, and the negative input terminal of the first optocoupler, respectively. The first voltage regulator circuit is used to regulate the voltage output by the first output winding.
4. The voltage isolation circuit according to claim 3, characterized in that, The voltage isolation circuit also includes a first capacitor; One end of the first capacitor is connected to the positive output terminal of the first output winding and the input terminal of the first voltage regulator circuit, respectively. The other end of the first capacitor is connected to the negative output terminal of the first output winding and the ground terminal of the first voltage regulator circuit, respectively. The output terminal of the first voltage regulator circuit is connected to the first output terminal of the second optocoupler, and the ground terminal of the first voltage regulator circuit is connected to the negative input terminal of the first optocoupler.
5. The voltage isolation circuit according to claim 4, characterized in that, The voltage isolation circuit also includes a second capacitor; One end of the second capacitor is connected to the output terminal of the first voltage regulator circuit and the first output terminal of the second optocoupler, respectively, and the other end of the second capacitor is connected to the ground terminal of the first voltage regulator circuit and the negative input terminal of the first optocoupler, respectively.
6. The voltage isolation circuit according to claim 5, characterized in that, The voltage isolation circuit also includes a current-limiting resistor; The current-limiting resistor is disposed in the circuit formed by the second capacitor, the second optocoupler and the first optocoupler.
7. The voltage isolation circuit according to claim 2, characterized in that, The voltage isolation circuit also includes a first voltage regulator circuit and a second voltage regulator circuit; The first voltage regulator circuit is connected to the positive output terminal of the first output winding, the negative output terminal of the first output winding, the first output terminal of the second optocoupler, and the negative input terminal of the first optocoupler, respectively. The first voltage regulator circuit is used to regulate the voltage output by the first output winding. The second voltage regulator circuit is connected to the positive output terminal of the second output winding, the negative output terminal of the second output winding, the first output terminal of the third optocoupler, and the negative input terminal of the second optocoupler, respectively. The second voltage regulator circuit is used to regulate the voltage output by the second output winding.
8. The voltage isolation circuit according to claim 2, characterized in that, The total number of the first optical coupler, the second optical coupler, and the third optical coupler is the number of optical couplers; The withstand voltage of the transformer is a multiple of the target withstand voltage of the optocoupler, and the target number is one less than the number of optocouplers.
9. The voltage isolation circuit according to claim 3, characterized in that, The first voltage regulator circuit includes a transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, and a Zener diode; One end of the first resistor is connected to the positive output terminal of the first output winding. The other end of the first resistor is connected to one end of the second resistor and the first terminal of the transistor. The second terminal of the transistor is connected to the first output terminal of the second optocoupler. The second terminal of the transistor is connected to one end of the third resistor. The other end of the third resistor is connected to one end of the fourth resistor and the adjustment terminal of the Zener diode. The negative terminal of the Zener diode is connected to the other end of the second resistor and the driving terminal of the transistor. The positive terminal of the Zener diode and the other end of the fourth resistor are both grounded. The negative output terminal of the first output winding and the negative input terminal of the first optocoupler are connected to the other end of the fourth resistor.
10. A power supply device, characterized in that, It includes a first signal circuit, a second signal circuit, and a voltage isolation circuit as described in any one of claims 1 to 9, wherein the voltage isolation circuit is connected to the first signal circuit and the second signal circuit respectively, and the voltage isolation circuit is used to electrically isolate the first signal circuit and the second signal circuit.