ผลของการเปลี่ยนแปลงคุณสมบัติอุปกรณ์และปัจจัยภายนอกต่อพฤติกรรมของบัลลาสต์อิเล็กทรอนิกส์ / สมชาย เปรมรุ่งพันธุ์ = Effects of device characteristic variations and external factors on the behaviors of electronic ballasts / Somchai Pramrungpun
The alteration of output power of an electronic ballast feeding a fluorescent lamp in a lamp ballast system caused by the variation of the system parameters was studied. Differential sensitivities of ballast’s output power with respect to supply voltage, operating frequency, as well as inverter circuit inductor and capacitor were calculated. Fundamental approximation analytical technique and linear fluorescent lamp model were used to establish the circuit equations, but power dependent of the linear lamp resistance was included in the calculations. Due to the power dependence of fluorescent lamp I-V characteristic, graphical technique had been used to determine the operating point of the lamp ballast system. The calculations were made for three different rated voltages. Three different combinations of load circuit parameters were investigated for each rated voltage value. Theoretical calculations reveal that, all the parameters considered influence the output power through normalized operating frequency, rated inverter voltage to lamp voltage ratio as well as differential sensitivity of lamp voltage with respect to the parameter under consideration. Experimental results are also given for comparison.
