Charging control unit

摘要

The amount of power generated by a solar cell is used for charging more efficiently. An activation determination means 4 activates a charging control circuit 3 by allowing a maximum output current from a solar cell 1 to a GND potential to flow and detecting that the output current is equal to or greater than current consumption of the charging control circuit 3 instead of monitoring an unstable output voltage from the solar cell 1. Thus, the charging control circuit 3 can be activated more precisely in comparison to a case where an output voltage is monitored under the condition that the charging control circuit 3 is operated only by the amount of power generated by the solar cell. Thereby, a power instrument 2 is charged more efficiently with the amount of power generated by the solar cell.

主权项

1. A charging control unit for controlling charging of a power retaining means with power from a solar cell that generates power by receiving light by a charging control circuit, the charging control unit, in order to charge an amount of power generated by the solar cell more efficiently, comprising:
an activation determining means for activating the charging control circuit by monitoring an output current from the solar cell to a reference potential and determining that the output current has reached a baseline current value, wherein the activation determining circuit comprises:
a current monitoring section for monitoring the output current from the solar cell;a first switching means for turning on or off the current monitoring section to a reference potential side;a second determination means for allowing the output current from the solar cell to flow from the current monitoring section to the reference potential side via the first switching means and monitoring the output current as a monitored current value to determine that the monitored current value has reached the baseline current value to output a switch controlling signal for turning off the first switching means and turning on from off a second switching means for turning on or off the output current from the solar cell to the charging control circuit; anda delay circuit for controlling the activation of the charging control circuit by outputting a delay signal that is delayed a predetermined time from a point when the monitored current has reached a predetermined current to the charging control circuit as an activation controlling signal, wherein a predetermined delay time from the point when the monitored current has reached the reference current value is a stable transition time of power fluctuation due to a rise in surface temperature of the solar cell.