Wide-range adjustable program-controlled direct current source with ripple output

Abstract

The utility model discloses a wide-range adjustable program-controlled direct current source with ripple output. The wide-range adjustable program-controlled direct current source comprises a signal generation unit, a front unit, a switching unit and an MOS (Metal Oxide Semiconductor) tube circuit, the switching unit comprises a switching circuit, a mutual inductor and a sampling circuit; the high-pass filter circuit is used for filtering a direct-current signal and retaining an alternating-current signal; the low-pass filter circuit is used for filtering an alternating current signal and retaining a direct current signal; the adder is used for superposing the direct current signal and the alternating current signal and then driving the MOS tube circuit; and the MOS tube transmits the processed model to the switching circuit, the mutual inductor and the sampling circuit. The scheme that two sets of current sources need to be adopted for ripple current output is omitted, the alternating current source and the direct current source are integrated in one current source, the size of the current source is reduced, and the wiring mode is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of direct current sources, in particular to an adjustable program-controlled direct current source with a wide range and ripple output. Background Art

[0002] Most of the existing DC current sources superimpose ripples using coupling methods, which require a set of DC sources and a set of AC sources. The AC current is superimposed on the DC through a coupler to output a DC current with ripples. The principle is as follows: Figure 1 The above method requires two current sources and a coupling device, which requires many components and a complex connection method. The DC and AC currents are coupled through the coupling device, which also has the following problems: 1) The ripple output accuracy is not high. Since the internal resistance of the DC source is not infinite, the AC current will be shunted, resulting in a smaller ripple output content.

[0003] 2) The coupling device generally uses a current CT. When DC current flows through the CT, it is easy to cause the CT magnetic saturation phenomenon, resulting in a larger AC current output error. Summary of the Invention

[0004] In response to the above-mentioned problems, the utility model proposes an adjustable programmable DC current source with a wide range and ripple output, which solves the defects in the prior art that two sets of current sources and one set of coupling devices are required, the number of required components is relatively large, and the connection method is complicated. The DC current and the AC current are coupled through the coupling device; the ripple output accuracy is not high. Since the internal resistance of the DC source is not infinite, the AC current will produce a shunt phenomenon, resulting in a change in the ripple output content; the coupling device generally uses a current CT. When the DC current flows through the CT, it is easy to cause the CT magnetic saturation phenomenon, resulting in a larger AC current output error.

[0005] The technical solutions adopted by this utility model are as follows:

[0006] A wide-range, programmable DC current source with ripple output, comprising a signal generating unit, a preamplifier unit, a switching unit, and a MOS tube circuit; the switching unit comprises a switching circuit, a mutual inductor, and a sampling circuit; the signal generating unit is used to amplify the reference signal in the subsequent circuit and is responsible for the logic switching part, selecting the appropriate gear according to the current size; the signal generating unit comprises an AC signal generator and a DC signal generator;

[0007] The front-end unit includes an AC part PID regulation circuit, a DC part PID regulation circuit, a high-pass filter circuit, a low-pass filter circuit and an adder; wherein the AC signal generator transmits a signal to the AC part PID regulation circuit, and the flow signal generator transmits a signal to the DC part PID regulation circuit;

[0008] The AC part PID regulation circuit and the DC part PID regulation circuit are used to correct the output value in real time according to the standard signal and the feedback signal to achieve a stable current and stable output value; the high-pass filter circuit is used to filter out the DC signal and retain the AC signal; the low-pass filter circuit is used to filter out the AC signal and retain the DC signal; the adder is used to superimpose the DC signal and the AC signal and then drive the MOS tube circuit;

[0009] The MOS tube transmits the processed model to the switching circuit, the mutual inductor and the sampling circuit.

[0010] The present invention eliminates the need for two current sources for ripple current output, integrating AC and DC sources into a single current source, reducing the size of the current source and simplifying wiring. The present invention addresses the existing problem of requiring two current sources and a coupling device, which requires numerous components and a complex connection method. The DC and AC currents are coupled via the coupling device; the ripple output accuracy is low because the internal resistance of the DC source is not infinite, causing AC current shunting, resulting in variations in the ripple output content; and the coupling device typically uses a current transformer (CT). When DC current flows through the CT, it can easily cause magnetic saturation in the CT, leading to larger errors in the AC current output.

[0011] Optionally, the adjustable programmable DC current source with a wide range and ripple output further includes a switching power supply, and the switching power supply adopts a high-power switching power supply.

[0012] Optionally, the adjustable programmable DC current source with a wide range and ripple output further includes a box, and the MOS tube is installed on one side of the box.

[0013] Optionally, the signal generating unit, the front unit, and the switching unit are installed on a side of the box away from the MOS tube, and the signal generating unit, the front unit, and the switching unit are arranged in sequence from top to bottom.

[0014] Optionally, a DC standard comparator is installed on the outside of the signal generating unit, the front unit and the switching unit.

[0015] Optionally, an output end is provided on one side of the box body close to the MOS tube.

[0016] Optionally, the AC part PID regulation circuit includes R1, R2, R3, C1, and A1.

[0017] Optionally, the DC part PID regulation circuit includes R4, R5, R6, C2, and A2.

[0018] Optionally, the high-pass filter circuit includes C3, R7, and A3.

[0019] Optionally, the low-pass filter circuit includes C4, R8, and A4; the adder includes R9, R10, R11, R12, and A5.

[0020] (3) Beneficial effects

[0021] 1. The DC source of this utility model includes a ripple output function, and has a wide output current range and built-in multiple current range gears to ensure stable and accurate output current.

[0022] 2. The utility model eliminates the need to use two sets of current sources for ripple current output, and integrates AC and DC sources into one current source, thereby reducing the size of the current source and simplifying the wiring method.

[0023] 3. The feedback sampling of the utility model adopts two methods: resistance sampling and DC comparator, and adds multiple ranges to meet the accuracy and stability requirements of the full range from 0.2mA to 600A. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a DC current source in the prior art of the utility model;

[0025] Figure 2 This is the principle diagram of the adjustable programmable DC current source with wide range and ripple output of embodiment 1 of the present utility model

[0026] Figure 3 This is a schematic diagram of a preamplifier unit of a wide-range programmable DC current source with ripple output according to embodiment 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of a switching circuit, a mutual inductor, and a sampling circuit of an adjustable programmable DC current source with a wide-range ripple output according to Example 1 of the present invention;

[0028] Figure 5 This is a schematic diagram of the installation of the upper half of an adjustable programmable DC current source with a wide-range ripple output according to embodiment 2 of the present invention.

[0029] Figure 6 This is a schematic diagram of the installation of the lower half of an adjustable programmable DC current source with a wide-range ripple output according to embodiment 2 of the present invention.

[0030] Figure 7 This is a schematic diagram of the back of an adjustable programmable DC current source with a wide range and ripple output according to embodiment 2 of the present invention.

[0031] The reference numerals in the figures are:

[0032] 1. Box, 2. Signal generating unit, 3. Preamplifier unit, 4. Switching unit, 5. DC comparator, 6. Switching unit, 7. Cooling fan, 8. Output terminal. DETAILED DESCRIPTION

[0033] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0034] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "left", "right", "inside", "outside", "front end", "rear end", "head", "tail", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In this embodiment, R1, R2··· refer to resistors, C1, C2··· refer to capacitors, and A1, A2··· refer to amplifiers.

[0036] Example 1

[0037] The technical solutions adopted by this utility model are as follows:

[0038] like Figure 1 、 Figure 2 As shown, a wide-range adjustable programmable DC current source with ripple output includes a signal generating unit, a preamplifier unit, a switching unit, and a MOS tube circuit; the switching unit includes a switching circuit, a mutual inductor, and a sampling circuit; wherein the signal generating unit is used to amplify the reference signal in the subsequent circuit and is responsible for the logic switching part, selecting the appropriate gear according to the current size. The signal generating unit includes an AC signal generator and a DC signal generator;

[0039] The front-end unit includes an AC part PID regulation circuit, a DC part PID regulation circuit, a high-pass filter circuit, a low-pass filter circuit and an adder; wherein the AC signal generator transmits a signal to the AC part PID regulation circuit, and the flow signal generator transmits a signal to the DC part PID regulation circuit;

[0040] The AC part PID regulation circuit and the DC part PID regulation circuit are used to correct the output value in real time according to the standard signal and the feedback signal to achieve a stable current and stable output value; the high-pass filter circuit is used to filter out the DC signal and retain the AC signal; the low-pass filter circuit is used to filter out the AC signal and retain the DC signal; the adder is used to superimpose the DC signal and the AC signal and then drive the MOS tube circuit;

[0041] The MOS tube transmits the processed model to the switching circuit, the mutual inductor and the sampling circuit.

[0042] It should be noted that the pre-unit in this embodiment (the principle is as follows Figure 3 In the circuit shown in Figure 1, R1, R2, R3, C1, and A1 form the AC PID control circuit, while R4, R5, R6, C2, and A2 form the DC PID control circuit. Based on the standard signal and feedback signal, the output value is adjusted in real time to achieve a stable current output value. C3, R7, and A3 form a high-pass filter circuit to filter out the DC signal while retaining the AC signal. C4, R8, and A4 form a low-pass filter circuit to filter out the AC signal while retaining the DC signal. R9, R10, R11, R12, and A5 form an adder that sums the DC and AC signals to drive the MOS transistor circuit.

[0043] It should be noted that the low-pass / high-pass filter in this embodiment uses a transformer for sampling. The feedback signal contains both AC and DC signals. For the AC preamplifier, the DC signal is not needed, so a high-pass filter is added to filter out the DC signal. For the DC preamplifier, the AC signal is not needed, so a low-pass filter is added to filter out the DC signal.

[0044] It should be noted that the MOS tubes and power tubes in the heat sink in this embodiment are high-power MOS tubes. A single tube can handle up to 150A of current. With a certain margin, only 10 pairs of tubes are needed to output a high current of 600A. The MOS tubes are mounted on a heat sink and cooled by a fan.

[0045] Signal generation unit: Two 16-bit D / A chips are used to generate AC and DC standard signals respectively.

[0046] It should be noted that the principle Figure 4As shown, the DC source current range in the switching circuit, mutual inductor, and sampling circuit of this embodiment is divided into two large gears. When the current is less than or equal to 1A, direct resistance sampling is adopted, with relay K2 energized and relay K1 disconnected. For currents below 1A, multiple gears are added, implemented through relays K7-K12 and sampling resistors R1-R6, ensuring an accuracy of 0.2mA-1A. When the current is greater than 1A, a DC comparator is used for sampling. DC comparators have the advantages of fast response speed and wide measurement frequency. They can sample both AC and DC currents. By adding relays K3-K6 and sampling resistors R7-R10, the full range accuracy of 1-600A is achieved.

[0047] It should be noted that the wide-range adjustable programmable DC current source with ripple output also includes a switching power supply. Its switching power supply adopts a high-power switching power supply. Each switching power supply can output a maximum current of 300A. The output voltage can also be adjusted according to the load size to reduce the heat generated by the MOS tube.

[0048] In this embodiment, the output AC and DC currents are switched and fed back to the load end through a transformer. The gear switching section adopts a multi-gear scheme, divided into two large gears: 1A and 600A. The feedback signal below 1A is directly sampled using a resistor. Below 1A, it is further divided into 6 gears, meeting the accuracy and stability requirements of 0.2mA-1A. 600A is sampled using a DC comparator. The DC comparator has the advantages of fast response speed and high bandwidth. It converts the large current into a small current signal in proportion, and then converts it into a feedback signal through a sampling resistor. In order to improve the accuracy and stability of the 600A gear, 4 gears are added between 1-600A, greatly improving the accuracy of the current source. Since the feedback signal contains DC and AC content, in order to obtain the signal of the required frequency band, a high-pass filter and a low-pass filter are added to the feedback signal to ensure the accuracy of the feedback signal.

[0049] During implementation of this embodiment, the waveform generation unit receives a power-up command, and the AC DAC generates a standard AC signal with variable frequency and amplitude. This signal, along with the feedback signal, is fed into the PID controller for proportional-integral operation. The output signal passes through a high-pass filter to remove the DC content, typically with a cutoff frequency set at 2.5Hz. The DC DAC generates a standard DC signal with variable amplitude. This signal, along with the feedback signal, is fed into the PID controller for proportional-integral operation. The output signal passes through a low-pass filter to remove the AC content, typically with a cutoff frequency set at 1Hz. The AC and DC signals are summed in an adder to output AC / DC signals, which drive the MOSFETs on the board to generate AC and DC currents. Example

[0050] like Figure 5 、 Figure 6 and Figure 7As shown, a wide-range adjustable programmable DC current source with ripple output includes a housing 1, and the MOS tube is mounted on one side of the housing. The signal generating unit 2, preamplifier unit 3, and switching unit 4 are mounted on the side of the housing away from the MOS tube, and the signal generating unit, preamplifier unit, and switching unit are arranged in order from top to bottom. A DC comparator 5 is mounted on the outside of the signal generating unit, preamplifier unit, and switching unit. A switch unit 6 is mounted on the top of the housing, and a cooling fan 7 is also mounted on one side of the MOS tube. An output terminal 8 is provided on the side of the housing near the MOS tube. In this embodiment, AC and DC currents are output to the load through the output terminal. The power supply terminal adopts AC200V power supply.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural transformation made by using the contents of the description and drawings of the present invention, directly or indirectly applied in other related technical fields, is also included in the scope of protection of the present invention.

Claims

1. An adjustable programmable DC current source with a wide range and ripple output, characterized in that: It includes a signal generating unit, a pre-unit, a switching unit, and a MOS tube circuit; the switching unit includes a switching circuit, a mutual inductor, and a sampling circuit; wherein the signal generating unit is used to amplify the reference signal in the subsequent circuit and is responsible for the logic switching part, selecting the appropriate gear according to the current size, and the signal generating unit includes an AC signal generator and a DC signal generator; The front-end unit includes an AC part PID regulation circuit, a DC part PID regulation circuit, a high-pass filter circuit, a low-pass filter circuit and an adder; wherein the AC signal generator transmits a signal to the AC part PID regulation circuit, and the flow signal generator transmits a signal to the DC part PID regulation circuit; The AC part PID regulation circuit and the DC part PID regulation circuit are used to correct the output value in real time according to the standard signal and the feedback signal to achieve a stable current and stable output value; the high-pass filter circuit is used to filter out the DC signal and retain the AC signal; the low-pass filter circuit is used to filter out the AC signal and retain the DC signal; the adder is used to superimpose the DC signal and the AC signal and then drive the MOS tube circuit; The MOS tube transmits the processed model to the switching circuit, the mutual inductor and the sampling circuit.

2. The adjustable programmable DC current source with wide range and ripple output according to claim 1, characterized in that: It also includes a switching power supply, which adopts a high-power switching power supply.

3. The adjustable programmable DC current source with wide range and ripple output according to claim 1, characterized in that: It also includes a box body, and the MOS tube is installed on one side of the box body.

4. The adjustable programmable DC current source with wide range and ripple output according to claim 3, characterized in that: The signal generating unit, the front unit and the switching unit are installed on a side of the box away from the MOS tube, and the signal generating unit, the front unit and the switching unit are arranged in sequence from top to bottom.

5. The adjustable programmable DC current source with wide range and ripple output according to claim 4, characterized in that: A DC standard comparator is installed outside the signal generating unit, the front unit and the switching unit.

6. The adjustable programmable DC current source with wide range and ripple output according to claim 4, characterized in that: An output end is provided on one side of the box body close to the MOS tube.

7. The adjustable programmable DC current source with wide range and ripple output according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that: The AC part PID regulation circuit includes R1, R2, R3, C1, and A1.

8. The adjustable programmable DC current source with wide range and ripple output according to claim 1, 2, 3, 4, 5 or 6, characterized in that: The DC part PID regulation circuit includes R4, R5, R6, C2, and A2.

9. The adjustable programmable DC current source with wide range and ripple output according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that: The high-pass filter circuit includes C3, R7, and A3.

10. The adjustable programmable DC current source with wide range and ripple output according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that: The low-pass filter circuit includes C4, R8, and A4; the adder includes R9, R10, R11, R12, and A5.

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