Abstract: A circuit for starting and operating a low wattage high intensity discharge lamp from a source of AC line voltage. The circuit includes a glow starter device having a first terminal connected to a first bimetal, a second terminal connected to a second bimetal, and third terminal connected to a rigid conductive member, the bimetals being electrically connected together at one end which makes a normally closed contact with the rigid member in the quiescent state of the device. A choke coil and a capacitor are series connected in that order between one of the AC input terminals and the second terminal of the starter device, and a second AC input terminal is connected to the third terminal of the starter. The first and third terminals of the starter device are connected across the discharge lamp terminals.

Abstract: The alumina arc tube of a high pressure sodium arc discharge lamp has a multiple turn wire starting aid wound therearound in order to reduce lamp starting voltage. The starting aid must extend longitudinally along the arc tube for a distance that is at least 10% of the arc length of the arc tube.