Processor based strobe with feedback
AssigneeHoneywell International Inc.
InventorsSimon Ha, Daniel C. Scheffler, Daniel J. Austin
Life of this patent
Estimating the term…
Abstract
Strobe control circuitry combines several approaches to limit in-rush current. One circuit limits initial circuit response to an applied voltage that has been switched from an inactive to an active state. Other circuitry switches from a high input impedance state to a low input impedance state a predetermined period of time after the applied voltage has switched to an active state.
Claims21
A strobe circuit comprising:
- a flashable source of illumination;
- a capacitor, coupled to the source, for providing energy for flashing the source;
- a multi-state charging circuit, coupled to the capacitor, for charging same;
- a control circuit, coupled to the charging circuit, wherein the control circuit switches the charging circuit through a plurality of states to minimize in-rush current, and wherein a duty cycle parameter is increased within a selected flash cycle;
- a power supply wherein the power supply limits in-rush current to the control circuit, the control circuit adjusts a duty cycle parameter of the charging current;
- and
- wherein the duty cycle varies over several charging cycles in response to selected feedback.
A method of limiting charging in-rush current in an electrical unit that has an energy storage capacitor which is periodically charged and discharged, the method comprising:
- turning off charging current for a period of time;
- imposing a current limiting element and initiating a limited charging current of a first magnitude for a first time interval;
- establishing a charging current duty cycle, less than 100%;
- increasing the duty cycle in accordance with a preset schedule to charge the capacitor to a selected threshold;
- and discharging the capacitor and repeating the above steps during at least one subsequent charging cycle.
A strobe control circuit comprising:
- circuitry for accommodating input voltages having on the order of 100% amplitude variation;
- circuitry responsive to a selected candela output for altering a charging parameter;
- and
- circuitry for minimizing a current in-rush thereto.
A strobe circuit comprising:
- a flashable source of illumination;
- a capacitor, coupled to the source, for providing energy for flashing the source;
- a charging circuit, coupled to the capacitor, for charging same;
- a control circuit, coupled to the charging circuit, wherein the control circuit adjusts a duty cycle parameter of the charging current such that the duty cycle varies over several charging cycles in response to selected feedback.
Dependencies are inferred from the claim text.