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US 6,289,180 B1Granted
Photoflash charging circuit with current and voltage monitor
AssigneeIntel Corporation
InventorPeter Peide Jeng
Life of this patent
Estimating the term…
Abstract
A camera that includes a battery, a photoflash circuit, and a charging circuit to provide energy from the battery to the photoflash circuit is provided. The camera further includes a voltage monitor coupled to the battery to switch off the battery from the charging circuit when a voltage on the battery falls below a predetermined voltage value. The camera may also include a current monitor, coupled to the battery, to switch off the battery from the charging circuit when a current generated through the battery exceeds a predetermined current value.
Claims18
A camera comprising:
- a battery;
- a photoflash circuit;
- a charging circuit to provide energy from said battery to said photoflash circuit;
- a switch coupled between said charging circuit and said battery to provide energy to said charging circuit;
- a current monitor coupled to said battery and said switch, to switch off said battery from said charging circuit when a current through said charging circuit exceeds a predetermined current value, wherein said battery remains available to provide energy to a microcontroller and other circuits of said camera monitor including a hysteresis margin to prevent oscillation from occurring in said current monitor;
- a strobe control section coupled to said current monitor, said strobe control section to transmit a control signal to said current monitor;
- and
- a voltage feedback section coupled to said charging circuit, said voltage feedback section including a hysteresis margin to maintain a voltage in said photoflash circuit.
5 more elements
In a camera, a method of monitoring a current through a battery coupled to a charging circuit, the method comprising:
- determining whether a current through said charging circuit exceeds a predetermined current value;
- comparing a first voltage to a second voltage;
- providing a hysteresis margin to prevent oscillation of said comparing;
- receiving a signal to control a strobe;
- feeding back a third voltage from said charging circuit;
- and
- switching off the battery from the charging circuit if the current through the charging circuit exceeds said predetermined current value, wherein said battery remains available to provide energy to other circuits of said camera.
4 more elements
A camera comprising:
- a battery;
- a photoflash circuit;
- a charging circuit to provide energy from said battery to said photoflash circuit;
- a switch coupled between said battery and said charging circuit to provide energy to said charging circuit;
- a voltage monitor, coupled to said battery and said switch, to switch off said battery from said charging circuit when a voltage on said battery falls below a predetermined voltage value;
- and
- a current monitor, coupled to said battery and said switch, to switch off said battery from said charging circuit when a current through said charging circuit exceeds a predetermined current value, said voltage monitor including a hysteresis margin to prevent oscillation from occurring in said voltage monitor;
- a strobe control section coupled to said voltage monitor, said strobe control section to transmit a control signal to said current monitor;
- and
- a voltage feedback section coupled to said charging circuit, said voltage feedback section including a hysteresis margin to maintain a voltage in said photoflash circuit;
- and
- wherein upon said battery being switched off from said charging circuit, said battery remains available to provide energy to other circuits of said camera.
9 more elements
A camera comprising:
- a battery;
- a photoflash circuit;
- a charging circuit to provide energy from said battery to said photoflash circuit;
- a switch coupled between said battery and said charging circuit to provide energy to said charging circuit;
- a voltage monitor, coupled to said battery and said switch, to switch off said battery from said charging circuit when a voltage on said battery falls below a predetermined voltage value;
- a current monitor, coupled to said battery and said switch, to switch off said battery from said charging circuit when a current through said charging circuit exceeds a predetermined current value, said current monitor including a hysteresis margin to prevent oscillation from occurring in said current monitor;
- a strobe control section coupled to one of said current monitor and said voltage monitor, said strobe control section to transmit a control signal to one of said current monitor and said voltage monitor;
- and
- a voltage feedback section coupled to said charging circuit, said voltage feedback section including a hysteresis margin to maintain a voltage in said photoflash circuit;
- and
- a microcontroller coupled to said voltage monitor, wherein upon said battery being switched off from said charging circuit, said battery remains available to provide energy to said microcontroller and other circuits of said camera.
8 more elements
Dependencies are inferred from the claim text.