Abstract: An ignitor circuit for a gas discharge lamp includes a transformer and means for generating pulsatory voltages across a primary winding of the transformer to generate ignition pulses by means of a secondary winding of the transformer. The ignitor circuit further includes first means for measuring an amplitude of the ignition pulses, and second means for changing the pulsatory voltage across the primary winding, and thus changing the amplitude of the ignition pulses, in dependence on the measured amplitude of the ignition pulses. The ignitor circuit is capable of generating a suitable ignition pulse over a wide range of connection cable lengths.

Abstract: A transformer (10) which forms part of a lamp ignition switching device has at least its primary winding (12) composed of a foil. Moreover, the transformer has an air core. In this way a satisfactory coupling, which is also maintained at high temperatures, is obtained between the primary (12) and the secondary (11) winding. This switching device is very suitable to be built in a lamp and to ignite the lamp at a high temperature.

Abstract: A circuit arrangement for igniting a high-pressure discharge lamp (6), in which ignition voltages are generated by means of discharges from two capacitors (10, 14) through a primary winding (12) of a transformer. During this, the lamp (6) is connected to a secondary winding (4) of this transformer. One capacitor (14) is charged to a higher voltage than the other capacitor (10), the two capacitors being discharged alternately through breakdown elements (11, 15) associated with the capacitors (10, 14, respectively). An ignition pulse with a low peak value for igniting the lamp (6) in the cold state is then followed by an ignition pulse with a high peak value for igniting the lamp (6) if it should be in the hot state.

Abstract: Apparatus for starting and operating a high pressure discharge lamp includes a pair of input terms for connection to a high frequency inverter. A step-up transformer couples the input terminals to a pair of output terminals for connection of the discharge lamp. A switching arrangement including a voltage-multiplier circuit, is coupled to the primary winding of the transformer and includes a first branch comprising a first capacitor and a diode and a second branch comprising a diode. Between the first capacitor and the diode of the first branch is connected a third branch comprising a semiconductor switch such as a SIDAC. The first branch is connected through the transformer coil to a first supply source connection point. The second branch is connected to a tap point of the coil. The first and the second branch are connected via a common impedance including second capacitor and an inductor to a second supply source connection point.