Electronic system for generating and controlling light effects on projectors

An electronic system for generating and controlling light effects on a projector utilizing at least one arc lamp, comprising an electronic power unit provided with a transformer fed via transistors, a secondary circuit of said transformer being connected to feed terminals of said lamp, wherein within the secondary circuit of said transformer there is connected a means for withdrawing a proportion of the instantaneous current circulating through said secondary circuit to produce an electrical signal which is made available to a control block which also receives an electrical reference signal generated by a generator block, said control block being arranged to compare said two electrical signals and to set said transistors to a conducting or inhibiting state depending on the result of said comparison, in which the amplitude and frequency of said electrical reference signal are adjustable by trimmer means controlled by an operator to obtain light effects perceptible by human eyes.