A method and arrangement for controlling dimming to a lamp by a dimmer arrangement affected by ripple injection and/or superimposed supply authority ripple control signals upon the AC mains supply input wave signal

摘要

A method for controlling dimming of a dimmer arrangement to minimise effects of a ripple injection signal upon an AC mains supply input wave signal received by the dimer arrangement comprising: filtering a ripple injection signal from an AC mains supply input wave signal having said ripple injection signal superimposed thereon; inverting the filtered ripple injection signal; combining the inverted filtered ripple injection signal with the AC mains supply input wave signal having said ripple injection signal superimposed thereon to eliminate the ripple injection signal from the AC mains supply input wave signal to provide an AC mains supply wave signal from which a true zero crossing detection signal is derivable; wherein an input of the derived true zero crossing detection signal to a gate drive arrangement of the dimmer arrangement generates a timing reference signal to control an OFF or ON period for a load control arrangement of the dimmer arrangement, wherein said load control arrangement is adapted to turn OFF or ON the AC mains supply input wave signal having the ripple injection signal superimposed thereon to a lamp under the control of the dimmer arrangement for an ON or OFF period determined by the timing reference signal.