An automatic lamp detection technique for electronic ballasts

Based on a comprehensive comparison of fluorescent lamp parameters of major lamp manufacturers, this paper presents an automatic lamp power detection method that can differentiate the lamp power of tubular T8 and T12 fluorescent lamps. This method can be easily incorporated into existing electronic ballast control so that the same electronic ballast design can operate different lamps at their respective rated power levels. With this patented method, a universal electronic ballast can be designed to operate the full range of T8 and T12 fluorescent lamps from 18 W to 70 W without any power mismatch problem. Design criteria and practical verifications are included to confirm the theory behind this lamp power detection method.