Capacitor ballast
The specification discloses a capacitive ballast for operating a gas discharge lamp from a conventional low frequency power source. The effective restart voltage during each cycle is enhanced by a trigger capacitor or pulse transformer which functions to produce a short duration reignition current. Properly timed, the reduced lamp voltage caused by the injection of the reignition current will be approximately equal to the difference between the instantaneous potential of the power source at the time of reignition and the instantaneous magnitude of the voltage across the ballast capacitor. The proper magnitude of lamp current is thus re-established during each half cycle and thereafter sustained at a value which equals the rate of change of voltage across the ballast capacitor.
- Assignee:
- EDB-85-061142
- Patent Number(s):
- US 4476414
- OSTI ID:
- 5878259
- Country of Publication:
- United States
- Language:
- English
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