Process and circuit for controlling the colour temperature of a high pressure sodium lamp

摘要

In the method and the circuit arrangement for setting different colour temperatures in a pulse-driven high-pressure sodium discharge lamp, the colour temperature is shifted without any substantial change in the flux and the colour rendition index by changing the instantaneous pulse power which is supplied to the lamp. It is advantageous for the instantaneous power pulses to consist, during pulsed operation, of a radio-frequency oscillation having a specific basic frequency (fundamental frequency), and the instantaneous pulse power is changed by changing the basic frequency.