CIRCUIT FOR ENERGISING A GAS DISCHARGE LAMP

摘要

In a gas discharge lamp, when the current through the inductor (17) has increased to a point where the voltage drop across the resistor (15) exceeds the voltage of the reference source (23, 24), the comparator amplifier (20) triggers the monostabile multivibrator (18) causing the solid state switching device (14) to be turned off. This acts to collapse the magnetic field in the inductor (17) thereby causing a large flyback voltage to appear across the lamp (11) sufficient to light the lamp. At the end of the predetermined time period of the low output state of the monostabile multivibrator (18), its output turns the solid state switching device (14) on, allowing current to flow from the power supply (16) through the inductor (17) and the lamp (11), thereby maintaining the lamp in the lit state and increasing the magnetic field in the inductor (17). The current flow through the lamp, when the solid state switching device (14) is on, is in the opposite direction from the current flowing through the lamp when the solid state switching device is off.