| US 7,462,996 B2 | ||
| Method of operating a lamp with a power controller having current limited RMS regulated output | ||
| Ernest C. Weyhrauch, Richmond, Ky. (US); Matthew B. Ballenger, Lexington, Ky. (US); George B. Kendrick, Lexington, Ky. (US); and Brent J. Eastwood, Lexington, Ky. (US) | ||
| Assigned to Osram Sylvania Inc., Danvers, Mass. (US) | ||
| Filed on Oct. 02, 2006, as Appl. No. 11/541,809. | ||
| Prior Publication US 2008/0106213 A1, May 08, 2008 | ||
| Int. Cl. H05B 37/02 (2006.01) | ||
| U.S. Cl. 315—308 [315/307; 315/291; 315/DIG. 4] | 4 Claims |
| 1. A method of converting a line voltage to an RMS load voltage in a lamp, the method comprising the steps of:
connecting a control circuit to a lamp terminal, the control circuit including a switch and a microcontroller that operates
the switch to establish an RMS load voltage for the lamp;
sensing a load voltage of the lamp;
comparing, in the microcontroller, the sensed load voltage to a reference RMS voltage; and
adjusting operation of the switch in response to the comparison so that the RMS load voltage is substantially constant at
the reference RMS voltage over a first operating range of the line voltage and adjusting operation of said switch so that
the RMS load voltage decreases with decreasing line voltage at non-zero line voltages less than the first operating range,
wherein the first operating range of the line voltage is defined to include a predetermined normal line voltage, to have a
maximum greater than the predetermined normal line voltage, and to have a minimum less than the predetermined normal line
voltage, the minimum being defined as a non-zero line voltage at which a load current is a predetermined maximum.
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