The electronic scheme adjustment process is a gradual process, and its principles are as follows:
First outside then inside.
Adjust the structural part first and then the electrical part
Adjust independent projects first, and then adjust mutually affected projects
Adjust the static parameters first and then the dynamic parameters
Adjust the basic indicators first, and then adjust the indicators that have a great impact on quality.
General process flow for overall adjustment of electronic scheme.
The whole machine debugging steps of the electronic scheme shall be clearly and carefully specified in the debugging process document, so that the operator can easily understand and execute. There are many kinds of electronic schemes and complex circuits. The types, requirements and technical indicators of internal unit circuits are also different, and the adjustment procedures are also different. However, in the general electronic scheme, the general process of adjustment includes the appearance inspection, structure adjustment, power supply adjustment, consumption test of the whole machine, adjustment of the whole machine, technical index test of the whole machine, etc.
1. Appearance inspection of the whole machine. The test items vary according to the product type and requirements, and the specific requirements can be carried out according to the process guidance card. The general electronic scheme mainly checks the shell appearance, foreign matters in the machine, function switch, screw fastening, button or button and other items.
2. Structural adjustment. The electronic scheme is an electromechanical integration product, and the purpose of structural adjustment is to check the firmness and reliability of the whole machine assembly. The specific contents include: whether the circuit board of each unit, components and the whole unit are connected firmly, whether there is looseness, whether the adjustment device is flexible, and whether the plug and socket are in good contact.
3. Adjust the power supply. Check and confirm that the switch of the product power supply system (such as the power circuit) is in the off position, check whether the power conversion switch meets the requirements, whether the fuse is installed, and whether the input voltage is correct, then plug in the plug of the power switch, turn off the power switch and power on.
After starting the machine, the power indicator lights up. At this time, pay attention to whether the indicator lights up, and whether there is discharge, ignition, smoke, abnormal smell, etc. In case of these phenomena, power off immediately for inspection. In addition, check whether various safety switches and control systems work and whether various heat dissipation systems work normally.
The power supply commissioning is usually carried out under no-load condition, and the initial commissioning is carried out after all loads of the power supply are cut off. Its purpose is to avoid the load of the power supply circuit without adjustment, and some electronic components are easily damaged. During commissioning, turn on the power supply of the power circuit board, measure whether there is a stable DC voltage output, and whether its value meets the design requirements, or adjust the sampling potentiometer to reach the rated value. Test the DC working point and voltage waveform of the detection point to check whether the working state is normal and whether there is self-excited vibration.
After the no-load commissioning is normal, the power load shall be adjusted carefully. When the initial adjustment is normal, add the rated load, measure each performance index, and observe whether it meets the design requirements. When the required optimum value is reached, lock the relevant adjusting parts (such as potentiometers, etc.) so that the power circuit has the best functional state required for load.
4. Power consumption test of the whole machine. The power consumption test of the whole machine is an important technical index of the electronic scheme. The voltage regulator commonly used in the test supplies the rated power supply voltage to the whole machine and measures the AC current during normal operation. The product of the two requires the power consumption of the whole machine. If the test value deviates from the design requirements, it indicates that there is a fault in the machine, and the whole machine should be comprehensively inspected.
5. Adjustment of the whole machine. After the adjusted cell circuit is assembled into the whole cell, its performance parameters are affected to different degrees. Therefore, after assembling the entire unit, make necessary adjustments to its unit substrate to ensure that the function of each unit substrate meets the requirements of the entire unit performance index.
6. Test of the whole technical index. Test the technical indicators of the whole machine that has been debugged to determine whether it meets the technical level required by the design. Different types of the whole machine have different technical indicators and test methods. If necessary, record test data, analyze test results, and write commissioning report.
In the process of adjustment, contact with various test equipment and power supplies, which often include high-voltage circuits, high-voltage large-capacity capacitors and MOS circuits. In order to protect the personal safety of the adjustment personnel and avoid the damage of the test instruments and components, the safety operation regulations must be strictly followed. The safety measures in the commissioning work mainly include the safety of the test environment, the safety of the power supply equipment, the safety of the test equipment and the operation safety. The experience and methods of electronic scheme adjustment are summarized into four words: circuit block isolation, AC after DC, attention to human-machine safety, and correct use of equipment.
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