Wide range power control for electric discharge lamp and press using the same

Claim 2

A power supply for controlling the application of power to an arc discharge lamp, comprising: a transformer having a primary winding adapted to be connected to A.C. power lines and a secondary winding adapted to be connected across said lamp; A.c. power supply control means connected to said primary winding for supplying A.C. voltage from the A.C. lines to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires and controlling the level of A.C. power supplied to said lamp from said A.C. lines, said control means being responsive to a control signal for varying the amount of power supplied to said lamp in dependence upon the value of said control signal; feedback means comprising sensor means positioned to receive radiation emitted from said lamp to provide an output signal having a value dependent upon the intensity of said radiation and, hence, upon the amount of power supplied to said lamp, and means for comparing said signal with a reference indicative of desired lamp output intensity and providing an error signal having a value in dependence upon any difference therebetween; means for supplying said control signal of a value dependent on said error to said A.C. power supply control means for controlling the A.C. power supplied to said lamp; and means for varying said reference for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 3

Apparatus as set forth in claim 1 wherein said comparing means comprises differential amplifier means responsive to both said output signal and said reference and including amplification so as to provide an error signal having a value dependent upon, but greater than, said difference between said reference and said output signal.

Claim 4

Apparatus as set forth in claim 1 wherein said power supply control means and said feedback means are electrically isolated.

Claim 5

Apparatus as set forth in claim 3 wherein said means for supplying said control signal includes radiation source means connected to said comparing means and responsive to said error signal for providing a radiation signal in accordance therewith, and radiation sensitive means connected to said power supply control means responsive to said radiation signal to control the level of said A.C. power supplied by said power supply control means in accordance therewith.

Claim 6

Apparatus as set forth in claim 4 wherein said comparing means further comprises means for providing a high current drive capability to said light source means.

Claim 7

Apparatus as set forth in claim 1 in combination with cooling means for reducing the temperature of said discharge lamp, the extent of said cooling being substantially proportional to the level of A.C. power supplied to said cooling means, and means for connecting said A.C. power control means to said cooling means to supply said A.C. power thereto, so that a reduction of power supplied to said lamp is associated with a reduction in cooling by said cooling means so as to thereby further stabilize the operation of said lamp at lower power levels.

Claim 8

Apparatus as set forth in claim 1 wherein said A.C. power control means includes means for controlling the phase angle at which said A.C. power is supplied to said transformer.

Claim 9

A power supply for controlling the application of power to an arc discharge lamp, comprising: a transformer having a primary winding adapted to be connected to A.C. power line and a secondary winding adapted to be connected across said lamp; A.c. power supply control means connected to said primary winding for supplying A.C. voltage from the A.C. lines to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires, and being responsive to a control signal for controlling the application of A.C. power to said lamp by controlling the phase angle at which said A.C. power is supplied to said transformer from said A.C. lines in dependence upon the value of said control signal; feedback means comprising radiation sensor means positioned to receive radiation emitted from said lamp to provide an output signal having a value dependent upon the intensity of said radiation and, hence, upon the amount of power supplied to said lamp, means for providing a reference signal, and differential amplifier means responsive to both said output signal and to said reference signal for providing an amplified error signal having a value dependent upon, but greater than, the difference between said reference and output signals; means for electrically isolating said A.C. power control means from said feedback means and for supplying said control signal having a value dependent on said error signal to said A.C. power supply control means for controlling the A.C. power supplied to said lamp; and means for varying said reference for controlling the A.C. power applied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 10

A power supply for controlling the application of power to an arc discharge lamp, comprising: a transformer having a primary winding adapted to be connected to A.C. power line and a secondary winding adapted to be connected across said lamp; A.c. power supply control means connected to said primary winding for supplying A.C. voltage from the A.C. lines to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires, and being responsive to a control signal for controlling the application of A.C. power to said lamp by controlling the phase angle at which said A.C. power is supplied to said transformer from said A.C. lines in dependence upon the value of said control signal; feedback means comprising radiation sensor means positioned to receive radiation emitted from said lamp to provide an output signal having a value dependent upon the intensity of said radiation and, hence, upon the amount of power supplied to said lamp, means for providing a reference signal, and differential amplifier means responsive to both said output signal and to said reference signal for providing an amplified error signal having a value dependent upon, but greater than, the difference between said reference and output signals; means for electrically isolating said A.C. power control means from said feedback means and for supplying said control signal having a value dependent on said error signal to said A.C. power supply control means for controlling the A.C. power supplied to said lamp; and means for varying said reference for controlling the A.C. power applied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 13

A method as set forth in claim 9 and further comprising the steps of cooling said lamp during the operation thereof, and controlling the amount of said cooling in accordance with the level of said A.C. power supplied to said lamp.

Claim 14

A method as set forth in claim 9 wherein said step of comparing includes the further step of amplifying whereby said error signal has a value dependent upon, but greater than, said difference.

Claim 15

A power supply for controlling the application of power to an arc discharge lamp, comprising: a transformer having a primary winding and a secondary winding; means for connecting said secondary winding to said lamp; A.c. power supply control means for connecting said primary winding to A.C. power lines for supplying A.C. voltage to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires and controlling the level of A.C. power supplied to said lamp from said A.C. power lines, said control means being responsive to a control signal for varying the amount of power supplied to said lamp in dependence upon the value of said control signal; feedback means for providing said control signal and including detection means for detecting the amount of power supplied to said lamp to provide an output signal, and means for comparing said output signal with a reference signal indicative of desired lamp output intensity and providing said control signal having a value in dependence upon any difference therebetween; and means for varying said reference signal for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 16

A power supply for controlling the application of power to an arc discharge lamp, comprising: a transformer having a primary winding and a secondary winding; means for connecting said secondary winding to said lamp; A.c. power supply control means for connecting said primary winding to A.C. power lines for supplying A.C. voltage to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires and controlling the level of A.C. power supplied to said lamp from said A.C. power lines, said control means being responsive to a control signal for varying the amount of power supplied to said lamp in dependence upon the value of said control signal; feedback means for providing said control signal and including detection means for detecting the amount of power supplied to said lamp to provide an output signal, and means for comparing said output signal with a reference signal indicative of desired lamp output intensity and providing said control signal having a value in dependence upon any difference therebetween; and means for varying said reference signal for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 17

A control system adapted to be connected to an arc discharge lamp for controlling the energization of the lamp, said control system comprising: a transformer including primary and secondary windings; power control means for connecting said primary winding to A.C. power lines, said power control means being responsive to a control signal for controlling the amount of power applied from said lines to said primary winding as a function of the value of said control signal; circuit means adapted to connect said secondary winding to said lamp so that A.C. voltage is supplied to said lamp of sufficient amplitude to ionize the gas in said lamp to cause the lamp to generate radiation, the intensity of which is a function of the amount of power applied to said primary winding; and, feedback means for detecting the intensity of radiation generated by said lamp and for providing said control signal to said power control means, the value of said control signal being a function of the detected intensity of said radiation, said feedback means includes additional means for adjusting said control signal for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 18

A control system adapted to be connected to an arc discharge lamp for controlling the energization of the lamp, said control system comprising: a transformer including primary and secondary windings; power control means for connecting said primary winding to A.C. power lines, said power control means being responsive to a control signal for controlling the amount of power applied from said lines to said primary winding as a function of the value of said control signal; circuit means adapted to connect said secondary winding to said lamp so that A.C. voltage is supplied to said lamp of sufficient amplitude to ionize the gas in said lamp to cause the lamp to generate radiation, the intensity of which is a function of the amount of power applied to said primary winding; and, feedback means for detecting the intensity of radiation generated by said lamp and for providing said control signal to said power control means, the value of said control signal being a function of the detected intensity of said radiation, said feedback means includes additional means for adjusting said control signal for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 19

A power supply for controlling the application of power to an arc discharge lamp, comprising: transformer coupling means adapted to be connected between A.C. power lines and said lamp; A.c. power supply means connected to said transformer coupling means for supplying A.C. voltage to said lamp through said transformer coupling means of sufficient amplitude to ionize the gas in said lamp so that said lamp fires, said power supply means being responsive to a control signal for controlling the application of A.C. power to said lamp by controlling the phase angle at which said A.C. power is supplied to said transformer coupling means in dependence upon the value of said control signal; feedback means including radiation sensor means positioned to receive radiation emitted from said lamp to provide an output signal having a value dependent upon the intensity of said radiation, means for providing a reference signal, and differential amplifier means responsive to both said output signal and to said reference signal for providing an amplified error signal having a value dependent upon, but greater than, the difference between said reference and output signals; means for electrically isolating said A.C. power supply means from said feedback means and for supplying said control signal having a value dependent on said error signal to said A.C. power supply means for controlling the A.C. power supplied to said lamp; and means for varying said reference signal for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.

Claim 20

A power supply for controlling the application of power to an arc discharge lamp, comprising: transformer coupling means adapted to be connected between A.C. power lines and said lamp; A.c. power supply means connected to said transformer coupling means for supplying A.C. voltage to said lamp through said transformer coupling means of sufficient amplitude to ionize the gas in said lamp so that said lamp fires, said power supply means being responsive to a control signal for controlling the application of A.C. power to said lamp by controlling the phase angle at which said A.C. power is supplied to said transformer coupling means in dependence upon the value of said control signal; feedback means including radiation sensor means positioned to receive radiation emitted from said lamp to provide an output signal having a value dependent upon the intensity of said radiation, means for providing a reference signal, and differential amplifier means responsive to both said output signal and to said reference signal for providing an amplified error signal having a value dependent upon, but greater than, the difference between said reference and output signals; means for electrically isolating said A.C. power supply means from said feedback means and for supplying said control signal having a value dependent on said error signal to said A.C. power supply means for controlling the A.C. power supplied to said lamp; and means for varying said reference signal for controlling the A.C. power supplied to said lamp in such a manner that the output intensity of said lamp is adjustable over a substantial portion of its range of output intensity without extinguishing.