Power factor measuring cut-off arrangement for and method of protecting a ballast-starter circuit from high pressure sodium lamp cycling malfunction
First Claim
1. In a luminaire of the type having a high pressure sodium lamp, an electrical power source of voltage and current, and ballast-starter means operatively connected between the power source and the lamp, said power source being normally operative for supplying voltage and current at a predetermined rated phase displacement condition across the lamp and ballast-starter means to light the lamp during nighttime conditions,a cycling cut-off arrangement for protecting the ballast-starter means from damage in the event of a cycling malfunction, wherein the lamp is alternately on and off, and wherein the power source supplies voltage and current to the lamp and ballast-starter means at a phase displacement condition different from said predetermined phase displacement condition, said cycling cut-off arrangement comprising:
- (a) sensor means for detecting the plase displacement condition across the lamp and ballast-starter means, and for generating a cut-off signal when the detected phase displacement condition is different from said predetermined phase displacement condition; and
(b) control means responsive to the generation of the cut-off signal for disabling the power source from the ballast-starter means to thereby protect the latter from damage in the event of a cycling malfunction.
2 Assignments
0 Petitions
Accused Products
Abstract
A cycling cut-off arrangement protects a ballast-starter circuit of a luminaire of the type having a high pressure sodium lamp from damage in the event of a cycling malfunction by sensing the change in power factor across the lamp during cycling, and disabling the ballast-starter circuit from its power source once cycling has been reliably detected. The method of sensing the power factor change, and of disabling the ballast-starter circuit is also disclosed, as well as a method of installing the arrangement on the luminaire with minimum retro-fitting required.
19 Citations
16 Claims
-
1. In a luminaire of the type having a high pressure sodium lamp, an electrical power source of voltage and current, and ballast-starter means operatively connected between the power source and the lamp, said power source being normally operative for supplying voltage and current at a predetermined rated phase displacement condition across the lamp and ballast-starter means to light the lamp during nighttime conditions,
a cycling cut-off arrangement for protecting the ballast-starter means from damage in the event of a cycling malfunction, wherein the lamp is alternately on and off, and wherein the power source supplies voltage and current to the lamp and ballast-starter means at a phase displacement condition different from said predetermined phase displacement condition, said cycling cut-off arrangement comprising: -
(a) sensor means for detecting the plase displacement condition across the lamp and ballast-starter means, and for generating a cut-off signal when the detected phase displacement condition is different from said predetermined phase displacement condition; and (b) control means responsive to the generation of the cut-off signal for disabling the power source from the ballast-starter means to thereby protect the latter from damage in the event of a cycling malfunction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A method of protecting from damage a ballast-starter means of a luminaire of the type having a high pressure sodium lamp energizable by an electrical power source operative for supplying voltage and current to the lamp and the ballast-starter means at a predetermined rated phase displacement condition during nighttime conditions, in the event of a cycling malfunction, wherein the lamp is alternately on and off, and wherein the power source spplies voltage and current to the lamp and the ballast-starter means at a phase displacement condition different from said predetermined phase displacement condition, said method comprising the steps of:
-
(a) detecting the phase displacement condition across the lamp and the ballast-starter means, and generating a cut-off signal when the detected phase displacement condition is different from said predetermined phase displacement condition; and (b) disabling the power source from the ballast-starter means in response to the generation of the cut-off signal to thereby protect the ballast-starter means from damage in the event of a cycling malfunction. - View Dependent Claims (16)
-
Specification