Simple Cold-Cathode Fluorescent-Lamp Supply Circuit Diagram. For back-lit LCD displays, this supply will drive a lamp. LT1072 drives Ql and Q2, and a sine wave appears across CI. LI is a transformer that steps up this voltage to about 1400 V. Dl and D2 detect lamp current and form a feedback loop to the LT1072 to control lamp brightness. C1 = MUST BE A LOW LOSS CAPACITOR. METALIZED POLYCARB WIMA FPK 2 (GERMAN) RECOMMENDED. L1 = SUMIDA 6345-020 OR COILTRONIX CTX110092-1. PIN NUMBERS SHOWN FOR COILTRONIX UNIT. L2 = COILTRONIX CTX300-4 * = 1 % FILM RESISTOR.
Cold-Cathode Fluorescent-Lamp Supply Circuit Diagram