Load current pulse control devices

Claim 2

In a device for delivering current from a d.c. voltage source to a light producing load, said load including a flash tube and electronic switch means connected therewith for terminating delivery of current to said load, and supply means connecting said voltage source to said load, and means for firing said flash tube and causing it to produce light, the voltage across said flash tube and said supply means decreasing when said flash tube is fired, the improvement comprising a light sensing circuit for sensing light produced by said flash tube and connected with said electronic switch means for causing said electronic switch means to terminate delivery of current to said flash tube upon receipt of a predetermined amount of light, and voltage developing means connected between said supply means and said light sensing circuit for developing and applying a voltage to said light sensing circuit only in response to the initiation of current through the flash tube to cause said flash tube to produce light, said voltage developing means including capacitive means for providing a current when the voltage across said flash tube decreases.

Claim 3

A device as in claim 1 wherein said supply means includes first and second means connecting said d.c. voltage source with said load, said light sensing circuit has first and second terminals, said voltage developing means comprising a resistance connected in series with said capacitive means from the first of said terminals to said first means to said supply means, and said second terminal is connected to said second means of said supply means, and said voltage developing means including voltage level establishing means connected across said terminals of said light sensing circuit and responsive to said current from said capacitive means for establishing said voltage for said light sensing circuit.

Claim 6

A device as in claim 1 wherein said light sensing circuit has first and second terminals, and said voltage developing means comprises a capacitive divider connected across said terminals of said light sensing circuit.

Claim 7

A device as in claim 1 wherein said supply means includes first and second means connecting said d.c. voltage source with said load, said light sensing circuit includes a pair of terminals, said voltage developing means includes maximum voltage determining means connected across said terminals of said light sensing circuit, means connecting a first of said terminals of asid light sensing circuit with the first means to said supply means, and said voltage developing means includes a resistance and capacitance circuit, means connecting said resistance and capacitive circuit from a second of said terminals of said light sensing circuit to said second means of said supply means.

Claim 8

A device as in claim 1 wherein said electronic switch is connected in series with said flash tube, said supply means includes first means connecting said d.c. voltage source with a first terminal of said flash tube and includes second means connecting said d.c. voltage source with said electronic switch, said light sensing circuit includes a pair of input terminals, said voltage developing means comprises a resistance connected in series with said capacitive means from the first of said terminals of said light sensing circuit to one of said means of said supply means, and said second terminal of said light sensing circuit is connected to the other means of said supply means, and diode means for establishing a maximum voltage level connected across said terminals of said light sensing circuit.

Claim 9

In a device for controlling the delivery of discharge current from a storage capacitor to a light producing load, and said load including a flash tube and an electronic switch connected thereto for terminating the delivery of current to the flash tube, the improvement comprising terminating circuit means connected to produce a terminating signal and to operate said electronic switch when said signal reaches a predetermined value, and voltage applying circuit means connected with said load and said terminating circuit means for providing an operating voltage to said terminating circuit means only when current is passed through said flash tube, and said voltage applying circuit means including capacitive means and diode means connected in series, said capacitive means being responsive to a voltage change across said load for supplying a current through said diode means, said diode means establishing a maximum operating voltage for said terminating circuit means.

Claim 10

In a device for controlling the delivery of discharge current from a storage capacitor to a light producing load, and said load including a flash tube and an electronic switch connected thereto for terminating the delivery of current to the flash tube, the improvement comprising terminating circuit means connected to produce a terminating signal and to operate said electronic switch when said signal reaches a predetermined value, and voltage applying circuit means connected with said load and said terminating circuit means for providing an operating voltage to said terminating circuit means only when current is passed through said flash tube, and said voltage applying circuit means including capacitive means and diode means connected in series, said capacitive means being responsive to a voltage change across said load for supplying a current through said diode means, said diode means establishing a maximum operating voltage for said terminating circuit means.

Claim 11

A device as in claim 7 wherein said terminating circuit means comprises an integrator circuit having a light sensor responsive to light from said flash tube and an integrating cApacitor, and said diode means of said voltage applying circuit means is connected across said light sensor and integrating capacitor of said integrator circuit for supplying said operating voltage thereto.

Claim 12

A device as in claim 7 wherein said terminating circuit means has input terminals, and includes a light sensor responsive to light from said load, means connecting said diode means across said input terminals of said terminating circuit means, and means connecting the series combination of said capacitive means and said diode means to said load.

Claim 13

A device as in claim 7 wherein said storage capacitor has said first and second terminals, means connecting a first terminal of said diode means with a terminal of said storage capacitor, and resistive means connecting said capacitive means between another terminal of said storage capacitor and the remaining terminal of said diode means.

Claim 14

A device as in claim 10 wherein said load is a flash tube having first and second electrodes, and one terminal of said storage capacitor is connected to an electrode of said flash tube, and the other terminal of said storage capacitor is connected through said electronic switch to the other electrode of said flash tube.

Claim 15

In a device for delivering current from a d.c. voltage source to a light producing load, said load including a flashtube and electronic switch means connected therewith for controlling current through said load, supply means connecting said voltage source to said load, and means for firing the flash tube and causing it to produce light, the improvement comprising light sensing circuit means for sensing light produced by said flash tube and connected with said electronic switch means for causing said electronic switch means to terminate delivery of current to said flash tube upon receipt of a predetermined amount of light, and voltage applying circuit means connected with said supply means and said light sensing circuit means for applying a voltage to said light sensing circuit means only in response to a decrease in voltage across said flash tube when said flash tube is fired to produce light, said voltage applying means including capacitive means and impedance means connected in series, said capacitive means providing a current through said impedance means when the voltage across said flash tube decreases upon production of light thereby, said current through said impedance means developing a voltage across said impedance means for providing an operating voltage to said light sensing circuit means.

Claim 16

In a device for delivering current from a d.c. voltage source to a light producing load, said load including a flashtube and electronic switch means connected therewith for controlling current through said load, supply means connecting said voltage source to said load, and means for firing the flash tube and causing it to produce light, the improvement comprising light sensing circuit means for sensing light produced by said flash tube and connected with said electronic switch means for causing said electronic switch means to terminate delivery of current to said flash tube upon receipt of a predetermined amount of light, and voltage applying circuit means connected with said supply means and said light sensing circuit means for applying a voltage to said light sensing circuit means only in response to a decrease in voltage across said flash tube when said flash tube is fired to produce light, said voltage applying means including capacitive means and impedance means connected in series, said capacitive means providing a current through said impedance means when the voltage across said flash tube decreases upon production of light thereby, said current through said impedance means developing a voltage across said impedance means for providing an operating voltage to said light sensing circuit means.