Research Of LED Driver Modules For COD Detector

Water resource is the material foundation to the survival of all life on earth. However, with the rapid increase of population and the rapid development of industrial economy, ecological balance is destroyed. Water pollution is increasingly serious, which has become a challenging issue facing the common around the world, and began to threaten the human survival and development. As the important indexes for evaluation of water quality, chemical oxygen demand(COD) through a survey of the organic and inorganic oxide concentration in the water, which reflects the pollution degree of reducing matter in water. The main method of measuring water COD can be divided into chemical method and physical method. The chemical method mainly refers to potassium dichromate oxidation method, which measurement accuracy, but the measuring time consuming, complex operation, and easy to produce secondary pollution. The physical method mainly refers to the ultraviolet absorption method. It has the advantage of fast measurement, high accuracy, and no secondary pollution, good real-time performance, but the price is relatively high, it is difficult to popularize and promote.Through to the investigation and research of the UV method COD analyzer in this article, using UV LED instead of traditional UV mercury lamp, we designed and verified the linear constant current driver module, which is suitable for small power LED. The LED driver module has many characteristics, such as dual channel, support time-series adjustable, high precision, low noise, low ripple coefficient and stable and reliable. It is suitable for a low cost, long service life, environmental pollution-free UV method of COD analyzer.