Charging device having a broad voltage changing range, automatic charging cutoff based on temperature detection, and charging status maintenance.

摘要

A charging circuit includes a negative temperature coefficient resistor element serving to verify the temperature of a rechargeable battery cell, such that once the cell is charged to saturation and the temperature of the cell rises to a predetermined level, the negative temperature resistor element will reduce its resistance in response, and in turn cause the charging circuit to automatically switch to a small current charging status, the charging status being maintained once the resistance of the negative temperature coefficient resistor element again starts to increase should the temperature of the cell that is being charged decrease, or should voltage fluctuation remain within a predetermined power supply voltage level, the charging circuit being arranged to reset itself once the rechargeable cell is removed or the power supply suspended.