The circuit shall be capable of monitoring the charge on a rechargeable battery. Based on the charge, the micro controller will provide charging power to the battery in the form of a pulse width modulated voltage from a charging source. The duty cycle used will depend on the charge state of the battery. If the battery is depleted the micro controller will provide a charge employing a large duty cycle (80-90%). If the battery is near 100% the duty cycle will be narrow (i.e. 10%) and eventually reduce to 0% when the battery is fully charged. The micro controller will vary the duty cycle to at least to other duty cycles between the two limits (10% and 90%) as the battery charges. The charging source shall consist of a solar panel or some other form of renewable power.
The device shall be able to display the battery % charge, the supply source voltage, the current being
used for the charge and shall have the ability to charge external devices such as cell phones. MP3
players etc., when the battery is charged as well as when it is being charged.
- Circuit shall have the ability to display relevant messages on an LCD display
- The circuit shall have the ability to measure charge current
- The circuit shall have the ability to modulate the charge pulsewidth
- Circuit shall have the ability to drive a piezo buzzer for access control audible indications