Power resource management system

DETAILED DESCRIPTION The present invention disclosed and claimed herein compromises a power management system for managing power distribution between an operating system and a recharging operation of a battery.
A positive power terminal is provided that is connected to the positive output of a DC power source and the positive input of the operating system.
A battery charge regulation circuit is operable to regulate power from a DC power source to the battery as a function of a charge control signal.
A current sensor senses the power drawn from the DC power source by both the operating system and the battery through the battery charge regulation circuit.
A regulation control circuit generates the charge control signal to control the battery charge regulation circuit to vary the current to the battery.
This maintains the power drawn from the DC power source below a predetermined level.
In another aspect of the present invention, the current sensor includes a sense node connected to the negative terminal of the battery and the negative terminal of the operating system.
A sense resistor is provided that is disposed between the sense node and the negative terminal of the DC power source.
The voltage developed across the sense resistor corresponds to the combined current of the operating system and the battery.
The regulation control circuit includes a comparator that is operable to compare the voltage from the sense node with a predetermined reference voltage.
When the voltage is above the predetermined reference, charge to the battery is reduced.
When the voltage on the sense node is below the predetermined reference, charge to the battery is increased.
In a yet further aspect of the present invention, the battery charge regulating circuit is comprised of a switching regulator having a switch associated therewith.
The regulator outputs pulses that determine the charge supplied to the battery, this comprising a buck regulator.