Metal vapor electric discharge lamp system
First Claim
1. A metal vapor electric discharge lamp system, comprising, a low-medium-high pressure metal vapor electric discharge lamp having a rated full radiation power in the range of about 200 to 400 watts per inch of said lamp, and transformer and control means including, a transformer comprising, a primary winding energized on alternating current electrical supply, a secondary winding loosely magnetically coupled with said primary winding by a main magnetic core portion of said transformer and connected in series electrical circuit with said metal vapor electric discharge lamp, having the latter consist essentially the load in said circuit, and magnetic shunt core means, and means for said magnetic shunt core means to be controlled to move to and from any one of at least two positions relative to said main magnetic core portion, said magnetic shunt core means in a first of said positions being substantially fully magnetically isolated from said main magnetic core portion to have said main magnetic core portion link magnetic flux from said primary winding with said secondary winding, and said magnetic shunt core means in the other of said positions, including a second position, being within the magnetic field of said main magnetic core portion and forming a magnetic shunt path with said main magnetic core portion physically between said primary and secondary windings to have said main magnetic core portion link a reduced amount of magnetic flux from said primary winding with said secondary winding, and said transformer and said low-medium-high pressure metal vapor electric discharge lamp being interrelated with one another according to properties so that with said magnetic shunt core means being in said first position said secondary winding is energized on operation of said transformer to have a relatively high power output level for striking an arc at a relatively high voltage across said metal vapor electric discharge lamp, whereupon voltage across said lamp sharply drops and current through said lamp sharply increases and is limited by impedance of said transformer, and with continued operation of said metal vapor electric discharge lamp, current through said lamp is decreased as voltage across said lamp increases for current and voltage across said metal vapor electric discharge lamp to stabilize at a relatively high radiation power level of operation of said metal vapor electric discharge lamp, and so that upon movement of said magnetic shunt core means from said first position to said second position relative to said main magnetic core portion in response to operation of said control means, operation of said transformer and said metal vapor electric discharge lamp is continued and said secondary winding is energized to have a relatively low power output level and said metal vapor electric discharge lamp accordingly thereafter stably operates at a radiation power level being less than about 70% full radiation power of said lamp.
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Accused Products
Abstract
A lamp system is provided wherein a high radiation intensity metal vapor electric discharge lamp is matched with a controllable regulating transformer which is characterized by having a sufficiently high open circuit voltage for striking an arc across the lamp and by having loose coupling between primary and secondary windings along with high impedance of the secondary winding sufficient for limiting an initially high starting current through the lamp to a value whereby, as the lamp warms up on power from the transformer, the lamp current decreases and the voltage across the lamp increases, allowing the lamp to reach a high radiation intensity level of operation, the system further being one in which the transformer is controlled by having controllable core structure to select a different intensity level of operation of the lamp.
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Citations
18 Claims
- 1. A metal vapor electric discharge lamp system, comprising, a low-medium-high pressure metal vapor electric discharge lamp having a rated full radiation power in the range of about 200 to 400 watts per inch of said lamp, and transformer and control means including, a transformer comprising, a primary winding energized on alternating current electrical supply, a secondary winding loosely magnetically coupled with said primary winding by a main magnetic core portion of said transformer and connected in series electrical circuit with said metal vapor electric discharge lamp, having the latter consist essentially the load in said circuit, and magnetic shunt core means, and means for said magnetic shunt core means to be controlled to move to and from any one of at least two positions relative to said main magnetic core portion, said magnetic shunt core means in a first of said positions being substantially fully magnetically isolated from said main magnetic core portion to have said main magnetic core portion link magnetic flux from said primary winding with said secondary winding, and said magnetic shunt core means in the other of said positions, including a second position, being within the magnetic field of said main magnetic core portion and forming a magnetic shunt path with said main magnetic core portion physically between said primary and secondary windings to have said main magnetic core portion link a reduced amount of magnetic flux from said primary winding with said secondary winding, and said transformer and said low-medium-high pressure metal vapor electric discharge lamp being interrelated with one another according to properties so that with said magnetic shunt core means being in said first position said secondary winding is energized on operation of said transformer to have a relatively high power output level for striking an arc at a relatively high voltage across said metal vapor electric discharge lamp, whereupon voltage across said lamp sharply drops and current through said lamp sharply increases and is limited by impedance of said transformer, and with continued operation of said metal vapor electric discharge lamp, current through said lamp is decreased as voltage across said lamp increases for current and voltage across said metal vapor electric discharge lamp to stabilize at a relatively high radiation power level of operation of said metal vapor electric discharge lamp, and so that upon movement of said magnetic shunt core means from said first position to said second position relative to said main magnetic core portion in response to operation of said control means, operation of said transformer and said metal vapor electric discharge lamp is continued and said secondary winding is energized to have a relatively low power output level and said metal vapor electric discharge lamp accordingly thereafter stably operates at a radiation power level being less than about 70% full radiation power of said lamp.
Specification