High-reliability high-efficiency electronic ballast
This patent describes an electronic ballast adapted to connect with the AC voltage on an ordinary electric utility power line and to power a gas discharge lamp. The AC voltage is electrically referenced to ground, the ballast comprising: full-wave rectifier means connected with the AC voltage and operable to provide a DC output across a pair of DC output terminals; push-pull inverter means connected in series with an inductor means to form a series-combination, the series-combination being connected across the DC output terminals; the inverter means being operable to provide a current-limited substantially sinusoidal output voltage between a first output terminal and a second output terminal; the magnitude of the voltage existing between the first output terminal and ground being is substantially equal to that of the voltage existing between the second output terminal and ground, the phasing of the voltage existing between the first terminal and ground being substantially equal and opposite with respect to the phasing of the voltage existing between the second terminal and ground; the frequency of the output voltage is substantially higher than that of the AC voltage; connect means to permit connection of a gas discharge lamp across the output terminals; and safety means connected in circuit between the output terminals and the inverter means, operable to cause substantial reduction in the magnitude of the output voltage; in case the magnitude of current flowing out of the first output terminal is substantially different from that of the current flowing into the second output terminal, the safety means is then non-responsive to any current flowing in the power lines.
- Assignee:
- EDB-87-131508; NOV-87-068724
- Patent Number(s):
- US 4675576
- OSTI ID:
- 6176173
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
24 POWER TRANSMISSION AND DISTRIBUTION
ALTERNATING CURRENT
BALLASTS
CONDUCTOR DEVICES
CONNECTORS
CURRENT LIMITERS
CURRENTS
DESIGN
DIRECT CURRENT
EFFICIENCY
ELECTRIC CURRENTS
ELECTRIC GROUNDS
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTRON TUBES
ELECTRONIC CIRCUITS
EQUIPMENT
GAS DISCHARGE TUBES
INVERTERS
OPERATION
POWER TRANSMISSION LINES
RECTIFIERS
RELIABILITY
SAFETY