Current-sharing high-power constant-current driving circuit, high-power constant-current circuit and laser equipment
By combining feedback control circuits and adjustment circuits, the current value of power switching devices is sampled and amplified, solving the problem of current imbalance in multiple parallel MOSFETs and achieving current balance and lifespan extension of the devices.
Patent Information
- Application Number
- CN202520500918.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-20
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-03-20
AI Technical Summary
In high-power applications, existing constant current circuits suffer from uneven current distribution in multiple parallel MOSFETs due to device inconsistency issues, leading to uneven heating, reduced device lifespan, or damage.
By employing a feedback control circuit and an adjustment circuit, the current value flowing through the power switching device is sampled, converted into a voltage value, and amplified. The control signal and the voltage difference are amplified into an electrical signal. The adjustment circuit amplifies the electrical signal by setting a gain factor and outputs it to the control terminal of the power switching device, thereby achieving current balance among the power switching devices.
It achieves current balancing among multiple parallel devices, avoids uneven heating, extends device life, and prevents damage.
Smart Images
Figure CN223828007U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit technology, and in particular to a high-power constant current driving circuit for current sharing, a high-power constant current circuit, and a laser device. Background Technology
[0002] Pulsed lasers are widely used in industrial processing, biomedicine, radar sensing, space exploration, and military research. As laser pulse power increases, existing constant current circuits cannot meet the requirements, and all constant current power supplies on the market use multiple parallel MOSFETs to achieve high-power constant current output.
[0003] However, due to the consistency issues of the devices, when the current power reaches a certain level, the current of multiple parallel MOSFETs will be uneven, with one MOSFET having a larger current than another, resulting in uneven heating, which reduces the lifespan of the devices or damages one of them. Utility Model Content
[0004] The main purpose of this invention is to provide a high-power constant current driving circuit, a high-power constant current circuit, and a laser device, which aim to achieve current sharing of multiple parallel devices.
[0005] To achieve the above objectives, the present invention proposes a high-power constant current driving circuit for current sharing, which includes: a feedback control circuit and multiple parallel constant current source circuits.
[0006] The constant current source circuit includes: a power switching device and an adjustment circuit;
[0007] The output terminal of the regulating circuit is connected to the controlled terminal of the power switching device, and the input terminal is connected to the first terminal of the feedback control circuit; the first terminal of the power switching device is connected to the power supply voltage, and the second terminal is connected to the second terminal of the feedback control circuit; the third terminal of the feedback control circuit is connected to the control signal.
[0008] The feedback control circuit is used to sample the current value flowing through the power switching device, convert the current value into a voltage value, and then output an amplified electrical signal to the adjustment circuit, which is the voltage difference between the control signal and the voltage value.
[0009] The adjustment circuit is used to amplify the electrical signal by a set gain factor, and output the amplified electrical signal to the control terminal of the power switching device to control the current value flowing through the power switching device.
[0010] Optionally, the power switching device is a voltage-type power switching device, and the regulating circuit is a voltage divider regulating circuit;
[0011] The voltage divider regulation circuit includes a first voltage divider unit and a second voltage divider unit. The first end of the first voltage divider unit is connected to the output end of the feedback control circuit, and the second end is connected to the first end of the second voltage divider unit and the controlled end of the voltage-type power switching device. The second end of the second voltage divider unit is grounded.
[0012] Optionally, the first voltage divider unit is a resistor, and the second voltage divider unit is a first potentiometer.
[0013] Optionally, the voltage-type power switching device includes a MOSFET; the gate of the MOSFET is connected to the second terminal of the resistor, the drain is connected to the power supply voltage, and the source is connected to the first terminal of the feedback control circuit.
[0014] Optionally, the power switching device is a current-type power switching device, and the regulating circuit includes: a current regulating unit;
[0015] The input terminal of the current regulation unit is connected to the feedback control circuit, and the output terminal is connected to the controlled terminal of the current-type power switching device.
[0016] Optionally, the current adjustment unit includes a second potentiometer;
[0017] The first terminal of the potentiometer is connected to the feedback control circuit, and the output terminal is connected to the controlled terminal of the current-type power switching device.
[0018] Optionally, the feedback control circuit includes: an operational amplifier and a sampling resistor;
[0019] The first end of the sampling resistor is connected to the second end of the power switching device and the negative input terminal of the operational amplifier, and the second end is grounded; the positive input terminal of the operational amplifier is connected to the control signal, and the output terminal is connected to the input terminal of the adjustment circuit.
[0020] This utility model also proposes a high-power constant current circuit, which includes: a control circuit, multiple current-sharing resistors connected in parallel, and the current-sharing high-power constant current drive circuit.
[0021] The control circuit is connected to the second terminal of the feedback control circuit; the first terminal of the current sharing resistor is connected to the power supply voltage, and the second terminal is connected to the first terminal of the load; the second terminal of the load is connected to the first terminal of the power switching device.
[0022] The control circuit is used to output a control signal to the feedback control circuit.
[0023] This utility model also proposes a laser device, which includes a laser and the high-power constant current circuit; the first end of the laser is connected to the second end of the current sharing circuit, and the second end is connected to the first end of the power switching device.
[0024] This invention proposes a high-power constant current driving circuit for current sharing, a high-power constant current circuit, and a laser device. The high-power constant current driving circuit for current sharing includes: a feedback control circuit and multiple parallel constant current source circuits; each constant current source circuit includes: a power switching device and an adjustment circuit; the output terminal of the adjustment circuit is connected to the controlled terminal of the power switching device, and the input terminal is connected to the first terminal of the feedback control circuit; the first terminal of the power switching device is connected to a power supply voltage, and the second terminal is connected to the second terminal of the feedback control circuit; the third terminal of the feedback control circuit is connected to a control signal; the feedback control circuit samples the current value flowing through the power switching device, converts the current value into a voltage value, and outputs an amplified electrical signal (the voltage difference between the control signal and the voltage value) to the adjustment circuit; the adjustment circuit amplifies the electrical signal by a set gain factor and outputs the amplified electrical signal to the control terminal of the power switching device to control the current value flowing through the power switching device. This invention collects the current flowing through the power switching device and uses an adjustment circuit to control the voltage or current at the controlled terminal of each power switching device to be equal, thereby achieving equal current values in each constant current source circuit. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of an embodiment of the current-sharing high-power constant current drive circuit of this utility model;
[0027] Figure 2 This is a schematic diagram of the first structure of the first embodiment of the current sharing high-power constant current drive circuit of this utility model;
[0028] Figure 3 This is a second structural schematic diagram of the first embodiment of the current sharing high-power constant current drive circuit of this utility model;
[0029] Figure 4 This is a schematic diagram of the first structure of the second embodiment of the current sharing high-power constant current drive circuit of this utility model;
[0030] Figure 5This is a schematic diagram of the second structure of the second embodiment of the current sharing high-power constant current drive circuit of this utility model;
[0031] Figure 6 This is a schematic diagram of the third structure of the first embodiment of the current sharing high-power constant current drive circuit of this utility model;
[0032] Figure 7 This is a schematic diagram of the structure of an embodiment of the high-power constant current circuit of this utility model;
[0033] Figure 8 This is a schematic diagram of another embodiment of the high-power constant current circuit of this utility model.
[0034] Explanation of icon numbers:
[0035]
[0036] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0038] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0039] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0040] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.
[0041] Reference Figure 1 This utility model proposes a high-power constant current driving circuit for current sharing, which includes: a feedback control circuit 20 and multiple parallel constant current source circuits 10.
[0042] The constant current source circuit 10 includes: a power switching device 120 and an adjustment circuit 110;
[0043] The output terminal of the regulating circuit 110 is connected to the controlled terminal of the power switching device 120, and the input terminal is connected to the first terminal of the feedback control circuit 20; the first terminal of the power switching device 120 is connected to the power supply voltage, and the second terminal is connected to the second terminal of the feedback control circuit 20; the third terminal of the feedback control circuit 20 is connected to the control signal.
[0044] The feedback control circuit 20 is used to sample the current value flowing through the power switching device 120, convert the current value into a voltage value, and then output an amplified electrical signal to the adjustment circuit 110 after the voltage difference between the control signal and the voltage value is amplified.
[0045] The adjustment circuit 110 is used to amplify the electrical signal by a set gain factor and output the amplified electrical signal to the control terminal of the power switching device 120 to control the current value flowing through the power switching device 120.
[0046] Reference Figure 1 Multiple constant current source circuits 10 are connected in parallel, wherein multiple power switching devices 120 are connected in parallel between the power supply voltage and ground potential. The output terminal of the regulating circuit 110 is connected to the control terminal of the power switching device 120 belonging to the same constant current source circuit 10. The regulating circuit 110 is used to control the on / off state of the corresponding power switching device 120, or the degree of on / off state of the power switching device 120, that is, the magnitude of the current flowing through the power switching device 120. This utility model does not limit the type of the power switching device 120, see reference. Figure 4 and Figure 5It can be a voltage-type power switching device 121, and the current value flowing through the voltage-type power switching device 121 is positively correlated with the voltage value at the controlled terminal of the voltage-type power switching device 121; the power switching device 120 can also be a current-type power switching device 122, and the current value flowing through the current-type power switching device 122 is positively correlated with the current value at the controlled terminal of the current-type power switching device 122.
[0047] Multiple power switching devices 120 are connected in parallel. The first terminal of each power switching device 120 is connected to a power supply voltage, and the second terminal is connected to the feedback control circuit 20. The feedback control circuit 20 samples the current flowing through each power switching device 120. It should be noted that this invention uses the feedback control circuit 20 to detect and sample the current flowing through each power switching device 120, and uses this as a feedback signal to perform calculations with the control signal to obtain the voltage difference. Considering that the voltage difference is relatively small, the feedback control circuit 20 also amplifies the voltage difference and outputs it to the adjustment circuit 110, so that the adjustment circuit 110 controls the current flowing through each power switching device 120. It is easy to understand that this invention uses the current flowing through each power switching device 120 as a feedback signal to ensure that the current flowing through each power switching device 120 is equal. Considering the differences between the power switching devices 120, this invention can achieve the technical effect that the voltage at the control terminal of each power switching device 120 may be different, but the current flowing through the power switching device 120 is equal.
[0048] The feedback control circuit 20 samples the current value flowing through the power switching device 120, and there are two cases:
[0049] Firstly, multiple power switching devices 120 connected in parallel simultaneously carry current. The feedback control circuit 20 converts the current values flowing through the multiple power switching devices 120 into voltage values, and then outputs an amplified electrical signal (the voltage difference between the control signal and the voltage) to the corresponding adjustment circuit 110 of each power switching device 120. After being amplified by the adjustment circuit 110, the signal is output to the controlled terminals of the multiple power switching devices 120, at which point the voltage / current values at the controlled terminals of the multiple power switching devices 120 are equal. It should be noted that after the feedback control circuit 20 converts the current values flowing through the power switching devices 120 into voltage values, it outputs the amplified electrical signal to the adjustment circuit 110, which belongs to the same constant current source circuit as the power switching devices 120.
[0050] Secondly, by configuring multiple power switching devices 120 connected in parallel, only one power switching device 120 has current flowing through it at any given time. The feedback control circuit 20 samples the current value flowing through the power switching device 120, converts it into a voltage value, and outputs an amplified electrical signal (the voltage difference between the control signal and the voltage) to the adjustment circuit 110. The adjustment circuit 110 adjusts the gain of the electrical signal and outputs it to the power switching device 120. The voltage / current value at the controlled end of the power switching device 120 is recorded when the current flowing through it is the first current value. Then, the power switching devices 120 with current flowing through them are adjusted at the next moment until the voltage / current value at the controlled end of all power switching devices 120 when the first current value is flowing through them is recorded. It is easy to understand that the multiple parallel power switching devices 120 are of the same type, for example, all are voltage-type power switching devices 121, or all are current-type power switching devices 122. In high-power operating scenarios, in order to achieve constant current drive, based on the recorded voltage / current values at the controlled terminals of each power switching device 120 when a first current value flows through it, a corresponding trigger command is sent to the regulating circuit 110 to make the current value flowing through each parallel power switching device 120 the same, and the current value within each constant current source circuit 10 the same. The specific value of the first current value can be changed according to actual needs, and the first current value can be determined by the R&D personnel or operators. The current output from the voltage source providing the power supply voltage flows through the power switching devices 120. This utility model does not limit the voltage value or source of the power supply voltage. In one example, the current-sharing high-power constant current drive circuit proposed in this utility model is applied to a laser device, and the power supply voltage can be provided by the laser power supply in the laser device. It is readily understood that the high-power constant current driving circuit for current sharing can be configured in the path between the laser power supply, the laser, and ground. Specifically, multiple constant current source circuits 10 are connected in parallel in this path; more specifically, multiple power switching devices 120 are connected in parallel in this path. It is conceivable that multiple parallel power switching devices 120 can provide a large current path to meet the power requirements of the laser. To avoid uneven current distribution and uneven heating caused by inconsistencies in the parallel power switching devices 120 when the current power reaches a certain level, the high-power constant current driving circuit for current sharing uses the current value flowing through the power switching devices 120 as a feedback signal to adjust each power switching device 120, thus solving the problem of uneven current distribution and ensuring that the current value flowing through each power switching device 120 is equal even when inconsistencies exist.
[0051] It should be noted that the feedback control voltage amplifies the voltage difference between the control signal and the voltage value by a constant gain factor, and outputs the amplified electrical signal to the adjustment circuit 110. The feedback control circuit 20 calculates the difference between the control signal and the voltage value to complete negative feedback. The control signal can be output by the controller in the laser device to control the switching of power switching devices 120 in the multiple constant current source circuits 10, thereby adjusting the laser's emission power. The gain factor by which the feedback control circuit 20 amplifies the voltage difference is determined by the researchers.
[0052] The adjustment circuit 110 is used to amplify the electrical signal by a set gain factor and output the amplified electrical signal to the control terminal of the power switching device 120.
[0053] It should be noted that, considering that the power switching device 120 can be either a voltage-type power switching device 121 or a current-type power switching device 122, the amplification of the feedback control circuit 20 and the adjustment circuit 110 can be combined in the following ways to match the specific type of the power switching device 120:
[0054] 1. Voltage-type power switching device 121; the feedback control circuit 20 amplifies the voltage difference and outputs a voltage signal, the adjustment circuit 110 further amplifies the voltage signal and outputs a voltage signal to the control terminal of the power switching device 120. The type of the set gain factor is voltage gain.
[0055] 2. Voltage-type power switching device 121; The feedback control circuit 20 converts and amplifies the voltage difference to output a current signal, and the adjustment circuit 110 converts the current signal into a voltage signal and amplifies it before outputting it to the control terminal of the power switching device 120; The type of the set gain multiple is transresistance gain.
[0056] 3. Current-type power switching device 122; the feedback control current amplifies the voltage difference and outputs a voltage signal, the adjustment circuit 110 converts the voltage signal into a current signal and amplifies it before outputting it to the control terminal of the power switching device 120; the type of the set gain multiple is transconductance gain.
[0057] IV. Current-type power switching device 122; The feedback control circuit 20 converts and amplifies the voltage difference to output a current signal, and the adjustment circuit 110 amplifies the current signal and outputs it to the control terminal of the power switching device 120; The type of the set gain multiple is current gain.
[0058] It should be noted that if the feedback control circuit 20 uses multiple output terminals to connect to multiple adjustment circuits 110 respectively, and outputs corresponding electrical signals to the adjustment circuits 110 according to the current flowing through the power switching device 120 in the constant current source circuit 10, the current flow control of multiple power switching devices 120 can be completed separately. However, in order to achieve synchronous control of multiple power switching devices 120, the feedback control circuit 20 uses one output terminal (e.g., the first terminal of the feedback circuit) to connect to multiple adjustment circuits 110, that is, the feedback control circuit 20 outputs the same electrical signal to the input terminal of the adjustment circuit 110 of each constant current source circuit 10; in order to overcome the uneven heating caused by the consistency problem of the power switching devices 120. The set gain factor of the adjustment circuit 110 can be manually adjusted. The operator can adjust the set gain factor of each adjustment circuit 110, thereby changing the control terminal of the power switching device 120 that is output by each adjustment circuit 110 to the same constant current source circuit 10, correcting the impact of the inconsistency problem of the power switching device 120, and ensuring that the current value flowing through each power switching device 120 is equal.
[0059] It is easy to understand that the current value flowing through the power switching device 120 is controlled by the electrical signal at the control terminal of the power switching device 120. In order to overcome the influence of the uniqueness of the power switching device 120 and make the current value flowing through each power switching device 120 equal, the operator can adjust the set gain factor of each adjustment circuit 110 to change the amplitude of the electrical signal output by each adjustment circuit 110 to the control terminal of the corresponding power switching device 120.
[0060] In one example, the power switching device 120 is a voltage-type power switching device 121; the operator first maintains the connection between one regulating circuit 110 and the feedback control circuit 20, and disconnects the other regulating circuits 110 from the feedback control circuit 20; assuming the number of constant current source circuits 10 is N, and the maximum current output by the power supply voltage is I, then the voltage value of the control signal input to the feedback control circuit 20 is adjusted to a value equal to the full-scale range of the control signal. The set gain factor of the retained adjustment circuit 110 is changed so that the current through the power switching device 120 is [value missing]. Record the voltage value at the control terminal of the power switching device 120 at this time, denoted as U1; keep the connection between another adjustment circuit 110 and the feedback control circuit 20, and disconnect the connection between the other adjustment circuits 110 and the feedback control circuit 20; repeat the above operation until the set gain multiple of all adjustment circuits 110 is completed. The operator restores the connection between all adjustment circuits 110 and the feedback control circuit 20, adjusts the voltage value of the control signal input to the feedback control circuit 20 to the full-scale voltage of the control signal, and adjusts the set gain multiple of each adjustment circuit 110 so that the voltage value at the control terminal of each power switching device 120 corresponds sequentially to U1 to UN, etc. It should be noted that U1 is the adjustment circuit 110 corresponding to the first power switching device 120 that is kept connected to the feedback control circuit 20 separately, and the current value through the first power switching device 120 is... At that time, the voltage value at the control terminal of the first power switching device 120. UN is the voltage value at which the adjustment circuit 110 corresponding to the Nth power switching device 120 is separately connected to the feedback control circuit 20, and the current value through the Nth power switching device 120 is... The voltage value at the control terminal of the Nth power switching device 120 is then determined. The other power switching devices 120 are handled similarly and will not be described further here. In this example, the voltage value at the control terminal of each power switching device 120 is first determined when a specific current value flows through it. Then, by adjusting the set gain factor of multiple adjustment circuits 110, the voltage value at the control terminal of the multiple power switching devices 120 in parallel is made equal to the voltage value when the specific current value flows through them, thereby ensuring that the current value flowing through all power switching devices 120 is equal.
[0061] This invention proposes a high-power constant current driving circuit for current sharing, a high-power constant current circuit, and a laser device. The high-power constant current drive circuit includes a feedback control circuit 20 and multiple parallel constant current source circuits 10. The constant current source circuit 10 includes a power switching device 120 and an adjustment circuit 110. The output terminal of the adjustment circuit 110 is connected to the controlled terminal of the power switching device 120, and its input terminal is connected to the first terminal of the feedback control circuit 20. The first terminal of the power switching device 120 is connected to a power supply voltage, and its second terminal is connected to the second terminal of the feedback control circuit 20. The third terminal of the feedback control circuit 20 is connected to a control signal. The feedback control circuit 20 samples the current value flowing through the power switching device 120, converts the current value into a voltage value, and outputs an amplified electrical signal (the voltage difference between the control signal and the voltage value) to the adjustment circuit 110. The adjustment circuit 110 amplifies the electrical signal by a set gain factor and outputs the amplified electrical signal to the control terminal of the power switching device 120 to control the current value flowing through the power switching device 120. This invention collects the current flowing through the power switching device 120 and uses the adjustment circuit 110 to control the voltage or current at the controlled terminal of each power switching device 120 to be equal, thereby achieving equal current values in each constant current source circuit 10.
[0062] In the first embodiment of this utility model, the power switching device 120 is a voltage-type power switching device 121, and the regulating circuit 110 is a voltage divider regulating circuit 110;
[0063] like Figure 2 As shown, the voltage divider regulation circuit 110 includes a first voltage divider unit 1110 and a second voltage divider unit 1120. The first end of the first voltage divider unit 1110 is connected to the output end of the feedback control circuit 20, and the second end is connected to the first end of the second voltage divider unit 1120 and the controlled end of the voltage-type power switching device 121. The second end of the second voltage divider unit 1120 is grounded.
[0064] The first voltage divider unit 1110, after being triggered, is used to adjust the impedance value of the first voltage divider unit 1110 and change the ratio of the impedance value of the first voltage divider unit 1110 to the impedance value of the second voltage divider unit 1120.
[0065] And / or, the second voltage divider unit 1120 is used to adjust the impedance value of the second voltage divider unit 1120 after being triggered, thereby changing the ratio of the impedance value of the first voltage divider unit 1110 to the impedance value of the second voltage divider unit 1120.
[0066] It is easy to understand that the current flowing through the voltage-type power switching device 121 is related to the voltage value at the controlled terminal of the voltage-type power switching device 121. The first voltage divider unit 1110 and the second voltage divider unit 1120 constitute a voltage divider regulation circuit 110. Assuming the impedance value of the first voltage divider unit 1110 is Z1 and the impedance value of the second voltage divider unit 1120 is Z2, the voltage gain DB of the voltage divider regulation circuit 110 is = Z2 / (Z1+Z2). When the impedance value of the first voltage divider unit 1110 and / or the second voltage divider unit 1120 changes, the voltage gain of the voltage divider regulation circuit 110 changes, thereby changing the voltage value output by the voltage divider regulation circuit 110 to the controlled terminal of the power switching device 120, and changing the current value flowing through the power switching device 120.
[0067] The first voltage divider unit 1110 is configured to adjust the impedance value of the first voltage divider unit 1110 after being triggered, thereby changing the ratio of the impedance value of the first voltage divider unit 1110 to the impedance value of the second voltage divider unit 1120, and / or the second voltage divider unit 1120 is configured to adjust the impedance value of the second voltage divider unit 1120 after being triggered, thereby changing the ratio of the impedance value of the first voltage divider unit 1110 to the impedance value of the second voltage divider unit 1120.
[0068] The first voltage divider unit 1110 and / or the second voltage divider unit 1120 may include a first potentiometer PT1 or a resistor divider, which can be used to change the ratio of the impedance values of the first voltage divider unit 1110 and the second voltage divider unit 1120. For example: Refer to Figure 3 and Figure 6 The first voltage divider unit 1110 includes a resistor, and the second voltage divider unit 1120 includes a first potentiometer PT1. The first end of the resistor is connected to the output terminal of the feedback control circuit 20, and the second end is connected to one end of the first potentiometer PT1 and the controlled terminal of the voltage-type power switching device 121. The other end of the first potentiometer PT1 is grounded. The voltage value at the controlled terminal of the voltage-type power switching device 121 can be adjusted by changing the impedance value of the first potentiometer PT1, thereby changing the ratio of the impedance values of the first voltage divider unit 1110 and the second voltage divider unit 1120.
[0069] The voltage-type power switching device 121 may include a MOSFET, a SiT transistor, an IGBT transistor, or a SITH transistor, etc.; if the voltage-type power switching device 121 may include a MOSFET, the gate of the MOSFET is connected to the second terminal of the resistor, the drain is connected to the power supply voltage, and the source is connected to the first terminal of the feedback control circuit 20.
[0070] In the second embodiment of this utility model, the power switching device 120 is a current-type power switching device 122, as shown in the figure. Figure 4 The regulating circuit 110 includes: a current regulating unit 1130;
[0071] The input terminal of the current regulating unit 1130 is connected to the feedback control circuit 20, and the output terminal is connected to the controlled terminal of the current-type power switching device 122. The current regulating unit 1130 is used to change the impedance value of the current regulating unit 1130 after being triggered, thereby adjusting the current value flowing into the current-type power switching device 122.
[0072] It is readily understood that the current flowing through the current-type power switching device 122 is related to the current value at the controlled terminal of the current-type power switching device 122. The current adjustment unit 1130 is disposed between the feedback control circuit 20 and the controlled terminal of the current-type power switching device 122. The impedance value of the current adjustment unit 1130 directly affects the current value at the controlled terminal of the current-type power switching device 122. The current adjustment unit 1130 changes its own impedance value according to a trigger command, thereby changing the current value at the controlled terminal of the current-type power switching device 122 and adjusting the current value flowing into the current-type power switching device 122.
[0073] Reference Figure 5 The current adjustment unit 1130 may include a second potentiometer PT2 or a resistor divider; the first terminal of the second potentiometer PT2 is connected to the feedback control circuit 20, and the output terminal is connected to the controlled terminal of the current-type power switching device 122; the first terminal of the resistor divider is connected to the feedback control circuit 20, the second terminal is connected to the controlled terminal of the current-type power switching device 122, and the third terminal is grounded. The current value at the controlled terminal of the current-type power switching device 122 can be changed by altering the impedance value between the second potentiometer PT2 and the resistor divider between the feedback control circuit 20 and the controlled terminal of the current-type power switching device 122.
[0074] The current-mode power switching circuit may include: power transistors, BJT transistors, thyristors, or GTR transistors, etc.
[0075] It should be noted that for the second potentiometer PT2 or the resistor divider, the position of the movable terminal in the second potentiometer PT2 or the resistor divider can be changed to adjust the gain of the electrical signal according to the trigger command. The second potentiometer PT can be triggered by the operator directly or by using a tool to adjust the position of the movable terminal.
[0076] Reference Figure 6 The feedback control circuit 20 includes: an operational amplifier VT and a sampling resistor RS;
[0077] The first end of the sampling resistor RS is connected to the second end of the power switching device 120 and the negative input end of the operational amplifier VT, and the second end is grounded; the positive input end of the operational amplifier VT is connected to the control signal, and the output end is connected to the input end of the adjustment circuit 110.
[0078] It should be noted that the sampling resistor RS is positioned between the second terminal of the power switching device 120 and ground. The current flowing through the power switching device 120 will flow through the sampling resistor RS to ground. The voltage value across the sampling resistor RS can be detected and used as the voltage value at the negative input terminal of the operational amplifier VT. Since the second terminal of the sampling resistor RS is grounded, the negative input terminal of the operational amplifier VT is connected to the first terminal of the sampling resistor RS. The positive input terminal of the operational amplifier VT is connected to the control signal, and the output terminal is connected to the input terminal of the adjustment circuit 110. The operational amplifier VT amplifies the voltage difference between the voltage value at the positive input terminal and the voltage value at the negative input terminal and outputs it to the adjustment circuit 110.
[0079] The feedback control current may also include multiple sampling resistors RS, which are connected in parallel. One end of each sampling resistor RS is grounded, and the other end is connected to the second terminal of the power switching device 120. Using multiple sampling resistors RS can shunt the current and prevent damage from overcurrent.
[0080] Reference Figure 7 and Figure 8 The present invention also proposes a high-power constant current circuit, which includes a control circuit, multiple current-sharing resistors RP connected in parallel, and the current-sharing high-power constant current drive circuit.
[0081] The control circuit is connected to the second terminal of the feedback control circuit 20. The first terminal of the current sharing resistor RP is connected to the power supply voltage, and the second terminal is connected to the first terminal of the load. The second terminal of the load is connected to the first terminal of the power switching device 120.
[0082] The control circuit is used to output control signals to the feedback control circuit 20.
[0083] It is readily understood that in the high-power constant current circuit proposed in this utility model, the load requires a high current supply for high-power operation. In application scenarios, it may involve setting the load current, which is controlled by the current-sharing high-power constant current drive circuit. Specifically, during normal load operation, the current output from the power supply voltage passes through the current-sharing resistor RP, the load, and the parallel constant current source circuit 10 to ground. Due to the large operating current, it is shunted in parallel through the current-sharing resistor RP to avoid overcurrent in a single resistor. This utility model does not limit the specific device, model, or operating power of the load. Figure 7 As shown, the voltage-type power switching device 121 is connected in series with the load in the path between the power supply voltage and ground, and the conduction or cutoff of the voltage-type power switching device 121 directly affects whether the power supply voltage can provide energy to the load. In the high-power constant current circuit, the control circuit is used to output a control signal to control the conduction or cutoff of the voltage-type power switching device 121; the controlled terminals of multiple voltage-type power switching devices 121 are interconnected and connected to the output terminal of the operational amplifier VT; the difference between the voltage value of the control signal and the voltage value of the sampling resistor RS is amplified by the operational amplifier VT and output to the controlled terminal of the voltage-type power switching device 121, ensuring that multiple voltage-type power switching devices 121 are simultaneously turned on or off.
[0084] like Figure 8 As shown, in order to avoid overcurrent in the sampling resistor RS, which could lead to resistor damage, this invention also uses multiple sampling resistors RS connected in parallel for current shunting.
[0085] It is easy to understand that the voltage amplitude of the control signal output by the control circuit is related to the resistance value of the sampling resistor RS. The operational amplifier VT amplifies the difference between the control signal and the voltage across the sampling resistor RS before outputting it. This difference directly affects the conduction level of the voltage-type power switching device 121, thereby affecting the current flowing through the voltage-type power switching device 121. To achieve matching between the voltage value of the control signal and the value of the sampling resistor RS, the specific value of the remaining one can be determined after determining any two of the voltage gain of the operational amplifier VT, the value of the sampling resistor RS, and the voltage amplitude of the control signal. For example, after determining the value of the sampling resistor RS and the voltage gain of the operational amplifier VT, the voltage amplitude of the control signal can be determined based on the value of the sampling resistor RS and the voltage gain. The control circuit may include a controller such as an MCU, FPGA, or SOC. The control circuit can output a corresponding control signal according to the actual application scenario to adjust the power of the voltage-type power switching device 121 by switching it on and off. Specifically, the controller in the control circuit can be used to output a corresponding control signal to the operational amplifier VT when triggered by the operator. Additionally, it should be noted that if the control circuit includes a digital controller, when the digital controller outputs a control signal to the operational amplifier VT, the output terminal of the digital controller is connected to a digital-to-analog converter (DAC); the DAC is used to convert the digital signal output by the digital controller into an analog signal. In one example, the control signal output by the control circuit is a PWM signal, and the control circuit adjusts the load power by controlling the duty cycle of the PWM signal.
[0086] It is easy to understand that if the high-power constant current circuit is applied to a laser device, the load is a laser.
[0087] This utility model also proposes a laser device, which includes a laser and the high-power constant current circuit; the first end of the laser is connected to the second end of the current sharing circuit, and the second end is connected to the first end of the power switching device 120.
[0088] The specific structure of the high-power constant current drive circuit for current sharing is as described in the above embodiments. Since this second subject adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be repeated here. The above descriptions are only optional embodiments of this utility model and do not limit the patent scope of this utility model. All equivalent structural transformations made under the inventive concept of this utility model using the content of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.
Claims
1. A high-power constant current driving circuit for current sharing, characterized in that, The high-power constant current drive circuit for current sharing includes: a feedback control circuit and multiple parallel constant current source circuits. The constant current source circuit includes: a power switching device and an adjustment circuit; The output terminal of the regulating circuit is connected to the controlled terminal of the power switching device, and the input terminal is connected to the first terminal of the feedback control circuit; the first terminal of the power switching device is connected to the power supply voltage, and the second terminal is connected to the second terminal of the feedback control circuit; the third terminal of the feedback control circuit is connected to the control signal. The feedback control circuit is used to sample the current value flowing through the power switching device, convert the current value into a voltage value, and then output an amplified electrical signal to the adjustment circuit, which is the voltage difference between the control signal and the voltage value. The adjustment circuit is used to amplify the electrical signal by a set gain factor, and output the amplified electrical signal to the control terminal of the power switching device to control the current value flowing through the power switching device.
2. The high-power constant current drive circuit for current sharing as described in claim 1, characterized in that, The power switching device is a voltage-type power switching device, and the regulating circuit is a voltage divider regulating circuit; The voltage divider regulation circuit includes a first voltage divider unit and a second voltage divider unit. The first end of the first voltage divider unit is connected to the output end of the feedback control circuit, and the second end is connected to the first end of the second voltage divider unit and the controlled end of the voltage-type power switching device. The second end of the second voltage divider unit is grounded.
3. The high-power constant current drive circuit for current sharing as described in claim 2, characterized in that, The first voltage divider unit is a resistor, and the second voltage divider unit is a first potentiometer.
4. The high-power constant current drive circuit for current sharing as described in claim 3, characterized in that, The voltage-type power switching device includes a MOSFET; the gate of the MOSFET is connected to the second terminal of the resistor, the drain is connected to the power supply voltage, and the source is connected to the first terminal of the feedback control circuit.
5. The high-power constant current drive circuit for current sharing as described in claim 1, characterized in that, The power switching device is a current-type power switching device, and the regulating circuit includes: a current regulating unit; The input terminal of the current regulation unit is connected to the feedback control circuit, and the output terminal is connected to the controlled terminal of the current-type power switching device.
6. The high-power constant current driving circuit for current sharing as described in claim 5, characterized in that, The current adjustment unit includes a second potentiometer; The first terminal of the potentiometer is connected to the feedback control circuit, and the output terminal is connected to the controlled terminal of the current-type power switching device.
7. The high-power constant current driving circuit for current sharing as described in any one of claims 1 to 6, characterized in that, The feedback control circuit includes: an operational amplifier and a sampling resistor; The first end of the sampling resistor is connected to the second end of the power switching device and the negative input terminal of the operational amplifier, and the second end is grounded; the positive input terminal of the operational amplifier is connected to the control signal, and the output terminal is connected to the input terminal of the adjustment circuit.
8. A high-power constant current circuit, characterized in that, The high-power constant current circuit includes: a control circuit, a plurality of current-sharing resistors connected in parallel, and a current-sharing high-power constant current drive circuit as described in any one of claims 1 to 7. The control circuit is connected to the second terminal of the feedback control circuit; the first terminal of the current sharing resistor is connected to the power supply voltage, and the second terminal is connected to the first terminal of the load; the second terminal of the load is connected to the first terminal of the power switching device. The control circuit is used to output a control signal to the feedback control circuit.
9. A laser device, characterized in that, The laser device includes a laser and a high-power constant current circuit as described in claim 8; the first end of the laser is connected to the second end of the current sharing resistor, and the second end is connected to the first end of the power switching device.