Starter unit for gas discharge lamps powered by alternating-current mains

Claim 1

A circuit for starting and powering a gas discharge lamp, such as a fluorescent lamp, from alternating current mains using direct current power to the lamp, the combination of rectifying means, a normally open relay contact in said circuit between said rectifier means and said alternating current mains, said normally open relay contact controlling the power input to said lamp means, a polarity-reversing switch means in said circuit connected in parallel between the output of said alternating current mains and said lamp, means responsive to energization of the alternating current mains for effecting reversal of said polarity-reversing switch means upon energization of said mains, time delay relay means controlling said normally open relay contact and responsive to each energization of the mains for closing said relay contact subsequent to each operation of said polarity-reversing switching means, and said time delay relay means including a coil and a capacitor in parallel circuit to each other, said time delay relay means being wired in said circuit in a branch separate from said polarity-reversing means; whereby each reversal of said polarity-reversing switch takes place under a no-load condition immediately upon energization of said circuit, and whereby said polarity-reversing switch means is connected to said alternating current mains only after both said polarity-reversing action has taken place and after said time delay of said time delay relay means has timed out.