Abstract：To solve the problem of measure data for color solution by the conventional drive circuit existing deviation, a closed-loop control method was proposed. The photoelectric receiving and adjusting circuit received the photoelectric signal and amplified it firstly. Then the signal collected was analog to digital(AD) converted,calculated and output by feedback adjustment circuit. The drive circuit compared the output with the default value lastly, adjusted the laser current, and made sure the receiver getting constant laser energy. The circuit adjusted by itself to reduce the deviation caused by the color solution during the measurement. The results show that the closed-loop control circuit has a strong adaptive ability for different color solution, a high stability of the signal and can improve the performance of the particle counter.

Keywords: particle counter; color solution；stability; self-adjustability