by admin_jsfisher » Fri Feb 26, 2016 2:03 pm
The first and last are current limited below your requirement. Not sure about the middle one, though.
By the way, one AA battery might yield about 2,000 mAh. Four of them x 1.5V x 2,000 mAh nets you 12,000 mWh of energy. Let's estimate your conversion to 9V efficiency at 67%, so you are at 8,000 mWh on the output side. 8,000 mWh / (9V x 200 mA) is about 4 to 4.5 hours.
Four hours is an eternity if the display is only on briefly for viewing. It is not very long at all if the display is left on for any length of time.
The first and last are current limited below your requirement. Not sure about the middle one, though.
By the way, one AA battery might yield about 2,000 mAh. Four of them x 1.5V x 2,000 mAh nets you 12,000 mWh of energy. Let's estimate your conversion to 9V efficiency at 67%, so you are at 8,000 mWh on the output side. 8,000 mWh / (9V x 200 mA) is about 4 to 4.5 hours.
Four hours is an eternity if the display is only on briefly for viewing. It is not very long at all if the display is left on for any length of time.