Circuit for HF operation for low presence discharge lamps - has rectifier and inverter and several opto-couplers, with controlled load circuit

摘要

The operational circuit has a DC voltage supply, followed by an inverter, and a series resonator circuit, supplied from the inverter with HF voltage. The resonator circuit contains a coupling capacitor, a current limiting choke, and a resonance capacity. The low pressure discharge lamp electrodes are preheated by a heating circuit. The circuit has several opto-coupler relays when load circuits are so controlled as to control the heating current and the lamp voltage. After the preheat and ignition phase, the lamp can be adjusted to operational condition which remains stable under picked-up measured values, such as ambient temp. and/or light strength. ADVANTAGE - Relatively low-cost operation of stabilised lamp control.