Abstract: A current-driven load such as LEDs or laser diodes is driven by a current driver having a two stages (or phases), the outputs of which have ripple which is forced to be out-of-phase with one another. In analog embodiments, an output (ripple or switching) of a master stage hysteresis controller is phase-shifted and scaled, and modulates the input of a slave stage hysteresis controller so that the slave stage pulls into a ripple-canceling phase. In digital embodiments, a faster of the two phases is designated “master”, maximum and minimum thresholds are set, and the slave phase's on time is based on a previous cycle's slave phase ON time, the master stage OFF time and an offset. The slave controller may “lock” to the anti-phase of the master stage (or phase). The ripple currents at the summed output of the master and slave stages substantially cancel.

Abstract: A laser spot tracker comprising a quadrant detector. A portion of a spot of laser light reflected from an object being illuminated (OBI) may be defocused to occupy a significant portion such as one-third of the field of view, while another portion remains focused, therefore allowing for quick calculation of the spot centroid. With such a “composite spot”, multiple target (OBI) positions may simultaneously be defined in elevation and azimuth with respect to null by analyzing the energy in each quadrant. The X and Y angle information (off null) for multiple targets (OBIs), and their codes may be displayed. For a large, defocused spot, two segmented multi-element detectors may be used, one in front of and the other behind the focal plane to reduce the effects of hot spots in a spot of laser light collected from an object being illuminated.

Abstract: A laser spot tracker comprising a quadrant detector. A portion of a spot of laser light reflected from an object being illuminated (OBI) may be defocused to occupy a significant portion such as one-third of the field of view, while another portion remains focused, therefore allowing for quick calculation of the spot centroid. With such a “composite spot”, multiple target (OBI) positions may simultaneously be defined in elevation and azimuth with respect to null by analyzing the energy in each quadrant. The X and Y angle information (off null) for multiple targets (OBIs), and their codes may be displayed. For a large, defocused spot, two segmented multi-element detectors may be used, one in front of and the other behind the focal plane to reduce the effects of hot spots in a spot of laser light collected from an object being illuminated.

Abstract: A current-driven load such as LEDs or laser diodes is driven by a current driver having a two stages (or phases), the outputs of which have ripple which is forced to be out-of-phase with one another. In analog embodiments, an output (ripple or switching) of a master stage hysteresis controller is phase-shifted and scaled, and modulates the input of a slave stage hysteresis controller so that the slave stage pulls into a ripple-canceling phase. In digital embodiments, a faster of the two phases is designated “master”, maximum and minimum thresholds are set, and the slave phase's on time is based on a previous cycle's slave phase ON time, the master stage OFF time and an offset. The slave controller may “lock” to the anti-phase of the master stage (or phase). The ripple currents at the summed output of the master and slave stages substantially cancel.

Abstract: A current-driven load such as LEDs or laser diodes is driven by a current driver having a two stages (or phases), the summed outputs of which have ripple which is forced to be out-of-phase with one another. In analog embodiments, an output (ripple or switching) of a master stage hysteresis controller is phase-shifted and scaled, and modulates the input of a slave stage hysteresis controller so that the slave stage pulls into a ripple-canceling phase. In a digital embodiment, a faster of the two phases is designated “master”, maximum and minimum thresholds are set, and the slave phase's on time is based on a previous cycle's slave phase ON time, the master stage OFF time and an offset. The slave controller preferentially “locks” to the anti-phase of the master stage (or phase) and the ripple current at the summed output substantially cancels.

Abstract: In a pulsed laser diode driver an energy storage capacitor is continuously being charged to a supply voltage Vr. When a pulse is initiated, energy stored in the capacitor is delivered to the laser diode load. The capacitor voltage Vd at the end of a pulse is used to control Vr to ensure that Vd is maintained above a minimum voltage Vm required to ensure operation of a current control device (such as FET) just above saturation. Test pulses (such as with attenuated currents or reduced pulsewidth) may be fired to determine an initial optimum value for Vr. After a test pulse, a slightly high estimate for Vr may be used and may be iterated (incremented) down to an optimum value Vm during a firing burst. A digital processor may be used to calculate and store data to optimize the performance. Various embodiments are disclosed.

Abstract: In a pulsed laser diode driver an energy storage capacitor is continuously being charged to a supply voltage Vr. When a pulse is initiated, energy stored in the capacitor is delivered to the laser diode load. The capacitor voltage Vd at the end of a pulse is used to control Vr to ensure that Vd is maintained above a minimum voltage Vm required to ensure operation of a current control device (such as FET) just above saturation. Test pulses (such as with attenuated currents or reduced pulsewidth) may be fired to determine an initial optimum value for Vr. After a test pulse, a slightly high estimate for Vr may be used and may be iterated (incremented) down to an optimum value Vm during a firing burst. A digital processor may be used to calculate and store data to optimize the performance. Various embodiments are disclosed.

Abstract: A current-driven load such as LEDs or laser diodes is driven by a current driver having a two stages (or phases), the summed outputs of which have ripple which is forced to be out-of-phase with one another. In analog embodiments, an output (ripple or switching) of a master stage hysteresis controller is phase-shifted and scaled, and modulates the input of a slave stage hysteresis controller so that the slave stage pulls into a ripple-canceling phase. In a digital embodiment, a faster of the two phases is designated “master”, maximum and minimum thresholds are set, and the slave phase's on time is based on a previous cycle's slave phase ON time, the master stage OFF time and an offset. The slave controller preferentially “locks” to the anti-phase of the master stage (or phase) and the ripple current at the summed output substantially cancels.

Abstract: A laser spot tracker device comprising a laser tracker receiver using a quadrant detector incorporated into a pair of binoculars or optical telescope system with a crosshair or reticule. Directional information from the laser tracker receiver is displayed to an operator (JTAC) to allow the reticule to be manually steered on to the target illuminated by the laser, thus identifying the target to the spotter. The laser code may be pre-selected to track a particular designator, or, the tracker may read out the code or codes of laser spots within its field of view.

Abstract: A laser spot tracker device comprising a laser tracker receiver using a quadrant detector incorporated into a pair of binoculars or optical telescope system with a crosshair or reticule. Directional information from the laser tracker receiver is displayed to an operator (JTAC) to allow the reticule to be manually steered on to the target illuminated by the laser, thus identifying the target to the spotter. The laser code may be pre-selected to track a particular designator, or, the tracker may read out the code or codes of laser spots within its field of view.

Abstract: A driver supplying a total current to a load has a plurality (n) of driver stages (ST1 . . . STn). One stage is a master stage. Each driver stage has a switching device (Q) and an inductor (L) connected in series between the switching device and the output of the driver stage. The switching devices are turned ON in sequence with one another, during a cycle time (Tc) which is determined by sensing current through the inductor (L1) in the master stage. When the switching device is turned ON current through the inductor rises, when the inductor current reaches the value of a demanded current the switch is turned OFF, and after the switch is turned OFF the inductor continues to supply (output) current to the load with a current which ramps down. A rectifying device (D) connected between the inductor and the supply line allows current to continue to flow in the inductor and be supplied to the load after the switch is turned OFF.

Abstract: A driver supplying a total current to a load has a plurality (n) of driver stages (ST1 . . . STn). One stage is a master stage. Each driver stage has a switching device (Q) and an inductor (L) connected in series between the switching device and the output of the driver stage. The switching devices are turned ON in sequence with one another, during a cycle time (Tc) which is determined by sensing current through the inductor (L1) in the master stage. When the switching device is turned ON current through the inductor rises, when the inductor current reaches the value of a demanded current the switch is turned OFF, and after the switch is turned OFF the inductor continues to supply (output) current to the load with a current which ramps down. A rectifying device (D) connected between the inductor and the supply line allows current to continue to flow in the inductor and be supplied to the load after the switch is turned OFF.

Abstract: A pulse forming and delivery system 10 is disclosed for forming and deliverying a pulse of electrical energy to a flashlamp 38. System 10 includes a capacitor 14 which is adapted to selectively store electrical energy from a power supply 16 and to transfer this electrical energy to flashlamp 38 when the gate portion of thyristor 12 is open. This gate portion is opened by controller 28. The total amount of light energy emanating from the laser and/or provided to flashlamp 38 is monitored by detector 42 and communicated to controller 22 by means of bus 44. When this total amount has exceeded a desired energy level, controller 22 prevents further electrical energy to be impressed upon switch controller 28 thereby, closing the gate portion of thyristor 12 and preventing any further transfer of energy to flashlamp 38.