project name: Based on LM339 voltage comparator module 4 road function: The module can do that voltage comparing with potentiometer voltage within 4 road at the same time, if the input voltage of the voltage is greater than the comparison (the voltage of the comparison are adjusted by the 4 road potentiometer), a signal output high level, whereas when the input voltage of the voltage light rain comparison, output low level signals. Functional specifications: 200 mil spacing terminal is power interface, the input power supply standard should be 5 v, 4 road input corresponding tag IN1 ~ IN4, PCB board and the output of some OUT1 ~ OUT4, each all the way next to the potentiometer marked IN1 ~ IN4, and is input and output number corresponding to the front, and marked as IN1 potentiometer compared with IN1 input, output OUT1 IN1 and IN1 potentiometer to adjust the reference voltage comparison results. This is the electronic components before welding and blank PCB diagram ![enter image description here][1] Real figure 1 ![enter image description here][2] Real figure 2 ![enter image description here][3] Real figure 3 ![enter image description here][4] Real figure 4 ![enter image description here][5] [1]: /editor/20160415/57104818516a3.jpg [2]: /editor/20160503/5728410389066.JPG [3]: /editor/20160503/5728410dae822.JPG [4]: /editor/20160503/57284115b2844.JPG [5]: /editor/20160503/5728411d43f24.JPG