CN213521672U - High-precision acquisition card isolation power supply - Google Patents
High-precision acquisition card isolation power supply Download PDFInfo
- Publication number
- CN213521672U CN213521672U CN202022050875.6U CN202022050875U CN213521672U CN 213521672 U CN213521672 U CN 213521672U CN 202022050875 U CN202022050875 U CN 202022050875U CN 213521672 U CN213521672 U CN 213521672U
- Authority
- CN
- China
- Prior art keywords
- switching tube
- power supply
- dsp
- diode
- analog
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model provides a high-precision acquisition card isolation power supply, which belongs to the technical field of data acquisition cards in measurement and control technology and comprises a working power supply, a DSP (digital signal processor), a conversion circuit, a feedback circuit and a rectification circuit; the DSP controls the conversion circuit to convert direct current of the working power supply into alternating current, and then the feedback circuit performs feedback regulation and the rectification circuit outputs the alternating current; the utility model discloses a detect the range of collection card input signal, then adjust the duty cycle of DSP output PWM ripples, and then the size of automatic adjustment working power supply has realized that the input of different range signal can provide the working power supply who matches all the time, has improved the work efficiency of collection card power, has realized collection card system power low-power consumption design.
Description
Technical Field
The utility model belongs to the technical field of the data acquisition card among the measurement and control technique, concretely relates to high accuracy acquisition card isolation power.
Background
In a design of a multipurpose and multi-signal type input acquisition card, various power supply designs are involved, such as a voltage source, a constant current source, an operational amplifier working power supply and the like. In order to automatically adapt to the amplitude change of +/-5V to +/-10V input signals, an input signal interface circuit is required to preprocess the signals.
A common way of signal preprocessing is to attenuate or amplify the input signal to match the signal amplitude requirements of the subsequent signal processing circuits. The circuit structure is simple, and the fixed output power supply chip is adopted to provide working voltage for the signal processing channel. The method has the disadvantages that the amplitude of an input signal is limited by the voltage of a working power supply, and if the amplitude of the input signal is too large, an output signal exceeds the range and does not change linearly; if the input signal is too small, the amplitude of the output signal changes within a small range, which will reduce the efficiency of the working power supply.
The utility model provides an another thinking, the mode through adjusting operating power supply voltage adapts to the input signal amplitude variation automatically to improve collection card power work efficiency, be favorable to collection card electrical power generating system low-power consumption design.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a: the utility model provides a high accuracy collection card isolation power, aims at improving collection card power work efficiency, reduces collection card consumption, reduces the device and generates heat and temperature drift, improves the collection precision.
In order to solve the technical problem, the utility model adopts the technical scheme that:
a high-precision acquisition card isolation power supply comprises a working power supply, a DSP (digital signal processor), a conversion circuit, a feedback circuit and a rectification circuit;
the conversion circuit comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and a transformer, wherein the input end of the first switch tube and the input end of the second switch tube are connected with the anode of the working power supply together, the output end of the first switch tube is connected with the input end of the third switch tube, the output end of the second switch tube is connected with the input end of the fourth switch tube, the output end of the third switch tube is connected with the output end of the fourth switch tube, the common end of the first switch tube and the third switch tube is connected with one end of a primary coil of the transformer, the common end of the second switch tube and the fourth switch tube is connected with the other end of the primary coil of the transformer, and the common end of the third switch tube and the fourth switch tube is grounded;
the DSP is provided with four paths of PWM ends, and the control end of the first switching tube, the control end of the second switching tube, the control end of the third switching tube and the control end of the fourth switching tube are respectively connected with the four paths of PWM ends of the DSP;
the rectifying circuit comprises a first diode, a second diode, a first capacitor and a second capacitor, wherein the anode of the first diode is connected with one end of a secondary coil of the transformer, the cathode of the first diode is connected with one end of the first capacitor, the anode of the second diode is connected with the other end of the secondary coil of the transformer, the cathode of the second diode is connected with one end of the second capacitor, the other end of the first capacitor is connected with the other end of the second capacitor, and the secondary coil of the transformer is grounded;
the feedback circuit comprises a first analog-to-digital converter and a second analog-to-digital converter, wherein the input end of the first analog-to-digital converter is connected with the cathode of the first diode, the output end of the first analog-to-digital converter is connected with the input end of the DSP, the input end of the second analog-to-digital converter is connected with the cathode of the second diode, and the output end of the second analog-to-digital converter is connected with the input end of the DSP.
Preferably, the digital signal processing device further comprises a first isolation module and a second isolation module, wherein an input end of the first isolation module is connected with an output end of the first analog-to-digital converter, an output end of the first isolation module is connected with an input end of the DSP, an input end of the second isolation module is connected with an output end of the second analog-to-digital converter, and an output end of the second isolation module is connected with an input end of the DSP.
Preferably, the model of the DSP is TMS320F 28335.
Preferably, the first switching tube, the second switching tube, the third switching tube and the fourth switching tube are MOS switching tubes.
Preferably, the wire diameters of the primary coil and the secondary coil of the transformer are both 0.2mm, and the turn ratio of the primary coil to the secondary coil is 3: 10.
preferably, the first isolation module and the second isolation module are both linear optocouplers 6N 137.
To sum up, owing to adopted above-mentioned technical scheme, the beneficial effects of the utility model are that:
the utility model discloses a detect the range of collection card input signal, then adjust the duty cycle of DSP output PWM ripples, and then the size of automatic adjustment working power supply has realized that the input of different range signal can provide the working power supply who matches throughout, has just so improved the work efficiency of collection card power, has realized collection card system power low-power consumption design.
Drawings
FIG. 1 is a circuit diagram of the present invention;
in the drawings: d1-a first switch tube, D2-a second switch tube, D3-a third switch tube, D4-a fourth switch tube, C1-a first capacitor, C2-a second capacitor, a T1-transformer, D5-a first diode, D6-a second diode, AD 1-a first analog-to-digital converter and AD 2-a second analog-to-digital converter.
Detailed Description
The features and properties of the present invention will be described in further detail below with reference to the accompanying drawings and examples.
As shown in FIG. 1, the utility model relates to a high accuracy capture card isolation power supply, including working power supply, DSP, converting circuit, feedback circuit and rectifier circuit, wherein:
the conversion circuit comprises a first switch tube D1, a second switch tube D2, a third switch tube D3, a fourth switch tube D4 and a transformer T1, wherein the input end of the first switch tube D1 and the input end of the second switch tube D2 are connected with the positive electrode of the working power supply together, the output end of the first switch tube D1 is connected with the input end of the third switch tube D3, the output end of the second switch tube D2 is connected with the input end of the fourth switch tube D4, the output end of the third switch tube D3 is connected with the output end of the fourth switch tube D4, the common end of the first switch tube D1 and the common end of the third switch tube D3 are connected with one end of the primary coil of the transformer T1, the common end of the second switch tube D2 and the fourth switch tube D4 is connected with the other end of the primary coil of the transformer T1, and the common end of the third switch tube D3 and the fourth switch tube D4 is grounded; the DSP is provided with four paths of PWM ends, and a control end of the first switching tube D1, a control end of the second switching tube D2, a control end of the third switching tube D3 and a control end of the fourth switching tube D4 are respectively connected with the four paths of PWM ends of the DSP; the working power supply is characterized in that 5V power supply voltage is input from a USB port, four switching tubes of the conversion circuit are provided with three pins, wherein the pins at two ends are pins of a normally-open end and are respectively connected into the conversion circuit to control the switching-on and switching-off of the conversion circuit. The middle pin is a pin for controlling the switch tube to be closed, and the DSP controls the switch tube to be closed so as to control the switching circuit to be closed. The model of the DSP can select TMS320F28335, which has a strong PWM signal output control function. MOS switching tubes are used for the four switching tubes, and an IRF820 chip can be selected specifically. The drain electrode of the MOS tube corresponds to one end pin of the switch tube, the source electrode corresponds to the other end pin of the switch tube, and the grid electrode corresponds to the middle pin of the switch tube.
The rectification circuit comprises a first diode, a second diode, a first capacitor and a second capacitor, wherein the anode of the first diode is connected with one end of a secondary coil of the transformer, the cathode of the first diode is connected with one end of the first capacitor, the anode of the second diode is connected with the other end of the secondary coil of the transformer, the cathode of the second diode is connected with one end of the second capacitor, the other end of the first capacitor is connected with the other end of the second capacitor, the secondary coil of the transformer is grounded, and the rectification circuit utilizes the principle of full-wave rectification. The transformer adopts the self-control step-up transformer, and the line footpath of primary and secondary coil is 0.2mm, and the turn ratio of primary and secondary coil is 3: 10.
the feedback circuit comprises a first analog-to-digital converter and a second analog-to-digital converter, wherein the input end of the first analog-to-digital converter is connected with the cathode of the first diode, the output end of the first analog-to-digital converter is connected with the input end of the DSP, the input end of the second analog-to-digital converter is connected with the cathode of the second diode, and the output end of the second analog-to-digital converter is connected with the input end of the DSP. The analog-to-digital converter can adopt a 12bits analog-to-digital converter inside the DSP.
In addition, the digital signal processing device also comprises a first isolation module and a second isolation module, wherein the input end of the first isolation module is connected with the output end of the first analog-to-digital converter, the output end of the first isolation module is connected with the input end of the DSP, the input end of the second isolation module is connected with the output end of the second analog-to-digital converter, and the output end of the second isolation module is connected with the input end of the DSP. The isolation module adopts a linear optocoupler 6N137, and the transformer and the isolation module realize the electrical isolation of input voltage and output voltage.
When the power supply is applied specifically, a working power supply inputs 5V power supply voltage, the DSP sends four paths of PWM control pulses to respectively control the four switching tubes, wherein the first switching tube and the fourth switching tube are in one group, and the second switching tube and the third switching tube are in the other group. When the DSP controls the first switching tube and the fourth switching tube to be closed, the second switching tube and the third switching tube are kept disconnected; similarly, when the DSP controls the second switching tube and the third switching tube to be closed, the first switching tube and the fourth switching tube are kept open. If the first switch tube and the fourth switch tube are closed, current flows through the first switch tube, then flows to a primary coil of the transformer from the common end of the first switch tube and the third switch tube, and then flows to the fourth switch tube from the common end of the second switch tube and the fourth switch tube; if the second switching tube and the third switching tube are closed, the current flows through the second switching tube, then flows to the primary coil of the transformer from the common end of the second switching tube and the fourth switching tube, and then flows to the third switching tube from the common end of the first switching tube and the third switching tube. The two groups of switching tubes are alternately opened and closed, so that the directions of current on the primary coil of the transformer are different, the original direct current is converted into alternating current, and the secondary coil obtains alternating voltage through the conversion of the transformer. The alternating voltage is rectified by a first diode and a second diode and filtered by a first capacitor and a second capacitor, and then the converted system working positive and negative power supplies are respectively output by a first filter and a second filter at the later stage.
The first analog-to-digital converter and the second analog-to-digital converter respectively collect working voltages which are rectified by the first diode and the second diode and filtered by the first capacitor and the second capacitor for sampling and feedback, then the duty ratio of PWM waves output by the DSP is adjusted, the frequency of the two groups of switching tubes which are alternately closed is controlled, the frequency of the converted alternating current is further adjusted, and therefore the size of the output voltage is changed. The output voltage is calculated as Vout＝D*5*NP/NSWhere D is the PWM pulse duty cycle, NPNumber of turns of secondary winding of transformer, NSFor transformersThe number of primary coil turns, 5 is the magnitude of the input voltage. Because D can be adjusted between 0 and 1 at will, the required output voltage can be obtained by adjusting D according to the required set size.
The actual measurement voltage output result is as follows:
Claims (6)
1. the utility model provides a high accuracy acquisition card isolation power which characterized in that: the device comprises a working power supply, a DSP, a conversion circuit, a feedback circuit and a rectification circuit;
the conversion circuit comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube and a transformer, wherein the input end of the first switching tube and the input end of the second switching tube are connected with the anode of the working power supply together, the output end of the first switching tube is connected with the input end of the third switching tube, the output end of the second switching tube is connected with the input end of the fourth switching tube, the output end of the third switching tube is connected with the output end of the fourth switching tube, the common end of the first switching tube and the common end of the third switching tube are connected with one end of a primary coil of the transformer, the common end of the second switching tube and the common end of the fourth switching tube are connected with the other end of the primary coil of the transformer, and the common end of the third switching tube and the common end of the fourth switching tube are grounded;
the DSP is provided with four paths of PWM ends, and the control end of the first switching tube, the control end of the second switching tube, the control end of the third switching tube and the control end of the fourth switching tube are respectively connected with the four paths of PWM ends of the DSP;
the rectifier circuit comprises a first diode, a second diode, a first capacitor and a second capacitor, wherein the anode of the first diode is connected with one end of the secondary coil of the transformer, the cathode of the first diode is connected with one end of the first capacitor, the anode of the second diode is connected with the other end of the secondary coil of the transformer, the cathode of the second diode is connected with one end of the second capacitor, the other end of the first capacitor is connected with the other end of the second capacitor, and the secondary coil of the transformer is grounded;
the feedback circuit comprises a first analog-to-digital converter and a second analog-to-digital converter, wherein the input end of the first analog-to-digital converter is connected with the cathode of the first diode, the output end of the first analog-to-digital converter is connected with the input end of the DSP, the input end of the second analog-to-digital converter is connected with the cathode of the second diode, and the output end of the second analog-to-digital converter is connected with the input end of the DSP.
2. The isolated power supply of a high precision capture card according to claim 1, wherein: the input end of the first isolation module is connected with the output end of the first analog-to-digital converter, the output end of the first isolation module is connected with the input end of the DSP, the input end of the second isolation module is connected with the output end of the second analog-to-digital converter, and the output end of the second isolation module is connected with the input end of the DSP.
3. The isolated power supply of a high precision capture card according to claim 1, wherein: the model of the DSP is TMS320F 28335.
4. The isolated power supply of a high precision capture card according to claim 1, wherein: the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all MOS tubes.
5. The isolated power supply of a high precision capture card according to claim 1, wherein: the wire diameter of the primary coil and the secondary coil of the transformer are both 0.2mm, and the turn ratio of the primary coil to the secondary coil is 3: 10.
6. the isolated power supply of a high precision capture card according to claim 2, wherein: the first isolation module and the second isolation module are both linear optocouplers 6N 137.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022050875.6U CN213521672U (en) | 2020-09-18 | 2020-09-18 | High-precision acquisition card isolation power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022050875.6U CN213521672U (en) | 2020-09-18 | 2020-09-18 | High-precision acquisition card isolation power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN213521672U true CN213521672U (en) | 2021-06-22 |
Family
ID=76447850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022050875.6U Active CN213521672U (en) | 2020-09-18 | 2020-09-18 | High-precision acquisition card isolation power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN213521672U (en) |
-
2020
- 2020-09-18 CN CN202022050875.6U patent/CN213521672U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109889047B (en) | Two-stage DC-DC converter suitable for wide input and output voltage range | |
| CN110611431B (en) | Primary side regulation control system and control method of active clamp flyback converter | |
| CN105186892B (en) | Numerical digit AC/DC power supply changeover devices | |
| CN107147300B (en) | The control device and method of critical continuous conduction mode flyback converter | |
| CN108880265B (en) | A kind of LLC resonant converter automatic resonance frequency tracker method | |
| CN205377693U (en) | Output current continuously adjustable high efficiency switching power supply | |
| CN106655834A (en) | Quasi-resonant primary-side constant-current control circuit and alternating current-direct current converter with the circuit | |
| CN205283402U (en) | Programme -controlled high voltage power supply | |
| CN104333239A (en) | High-efficiency totally-integrated AC-DC converter | |
| CN105226970A (en) | The D.C. regulated power supply that output polarity is changed automatically | |
| CN107124105B (en) | Improve the control system and method for isolated form three-level PFC converter PF | |
| CN213521672U (en) | High-precision acquisition card isolation power supply | |
| CN202150803U (en) | Voltage regulating and stabilizing device | |
| CN106487234B (en) | The output power control method of the flyback converter of electric current blend modes of operation | |
| CN209963957U (en) | Fixed-frequency resonant DC converter | |
| CN207265870U (en) | A kind of synchronous rectification integral control circuit | |
| CN201328102Y (en) | Secondary-side control device of transformer | |
| CN214473586U (en) | Detection device for sampling input end isolation voltage | |
| CN110247563A (en) | AC-DC conversion circuit and method and charger | |
| CN209982350U (en) | Power supply circuit and electric energy meter | |
| CN210297549U (en) | Switching power supply based on flyback transformer | |
| CN208971395U (en) | Isolation type switching power supply | |
| CN207304013U (en) | The power factor correction circuit compared based on stagnant ring | |
| CN112054525A (en) | Series active power filter | |
| CN206962712U (en) | A kind of adjustable DC high voltage power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |