Oil contamination particle detection board (1) - power supply, counting board

Introduction: Oil pollution particle counting circuit based on the principle of photoresist method

1. Product introduction:

This module is the power supply and counting board of the oil pollution particle detection board. It can compare and count the signals from the sensor signal board. , and finally sent to the microcontroller for reading. The power supply and counting board cannot be used alone and must be used in conjunction with the sensor signal board to achieve the effect of counting pollution particles.

2. Application scenarios:

It can be applied to equipment use and development projects such as portable oil particle detectors.

3. Product overview:

The power supply and counting board are one of the important components of the oil pollution particle detector. It mainly supplies power to each functional circuit in the board, and compares and counts the signal values ​​transmitted by the sensor signal board. There are a variety of expansion interfaces on the board, which can realize signal extraction and detection on the one hand. On the other hand, according to its design function, the counting signal output part can be installed on different particle detection equipment, and has certain adaptability.

4. Product parameters:

Working voltage: IN: DC24V
power module conversion voltage: ±15V, 5V, 3.3V
No-load test power: about 2W
Signal output: There are 6 reference voltages, which are compared with the sensor signal and output
Measured particle range: included 4, 6, 14, 21, 38, 70 (μm), etc.
using this detection circuit, the counting efficiency can be within ±10%, in line with the design indicators of the particle detector
PCB size: 10mm*10mm Double-layer board design single-sided layout

5 .Instructions for use:

This module needs to be used with a sensor signal board (see my personal homepage for details on the sensor signal board)
. After getting the module for the first time, connect the power supply, counting board and sensor signal board. The interface is shown in the schematic diagram below.
According to actual usage requirements, after testing, connect to the detector, modify the corresponding program and adjust the internal structure to fully adapt to the testing equipment.

6. Remarks:

This module is a pure hardware circuit. First, connect it according to the above schematic diagram; secondly, according to the actual project needs, formulate the appropriate sensor detection mechanical structure, main control chip and other models. Finally, the overall debugging is carried out to meet the design requirements.
This module is only a power supply and counting board, and needs to be matched with the sensor signal board to achieve the effect of counting pollution particles. For details about the sensor signal board, please see my homepage (Oil contamination particle detection board (2) - Sensor signal board).
It is estimated that the cost of all materials for the oil contamination particle detection boards (1) and (2) is about 500 yuan (excluding PCB).
This design has certain adaptability and can be used with various detectors on the market after further modification according to their design requirements.
According to different liquid particles, the actual test value is obtained, and calibrated with the offline test instrument to finally obtain the true value.
The attachment contains pin definition instructions for the power supply and counting board.
Note that a certain component is not soldered: Silk screen number: U29 (power module, DC24V to ±15V) is not soldered. Reason: I did not buy this device and used other external modules to achieve the corresponding functions.

7. Test video

demonstration video is a joint test of the power supply, counting board and sensor signal board, simply simulating particle changes, and testing the output voltage changes by continuously blocking the light signal.