Abstract: The invention relates to an arrangement for starting and supplying a discharge lamp provided with cold electrodes. The lamp is shunted by a starter circuit which consists of a series arrangement of at least a capacitor and a controlled semiconductor switching element having a bidirectional thyristor characteristic.According to the invention a resistor with a positive temperature coefficient is connected in series with the capacitor and the controlled semiconductor switching element. If the lamp fails to ignite the device produces substantially no radio interference owing to the high-ohmic value of the PTC resistor produced by an increase in its temperature. Furthermore, a controlled semiconductor switching element having a low blocking voltage can now be used. Normal starting of the lamp is hardly affected by the PTC resistor.

Abstract: A device for starting a discharge lamp by means of a transistor starter provided with an auxiliary transistor for stopping the starting procedure if the lamp fails to ignite.A zener diode is included in the control circuit of the auxiliary transistor, a capacitor is connected in parallel across the lamp, and a self-inductor is included in the connection from the lamp to the main transistor. The auxiliary transistor has a second function in that, by the action of the zener diode, the auxiliary transistor delays the conduction of the main transistor so that a large rise of the voltage between the lamp electrodes is produced, which provides a more reliable ignition of the lamp within a large temperature range.