PAGE 123 OF 150 · POWER SUPPLIES & BATTERIES
AA and AAA Battery Packs
Series cells add voltage.
LED SYMBOLTriangle points from anode to cathode; the arrows show light leaving the part.
Common cells
- Alkaline AA: 1.5 V, roughly 2,000 to 3,000 mAh.
- Alkaline AAA: 1.5 V, roughly 1,000 to 1,200 mAh.
- NiMH AA: 1.2 V nominal, roughly 1,900 to 2,800 mAh.
- NiMH AAA: 1.2 V nominal, roughly 700 to 1,000 mAh.
Packs
Four alkaline cells give 6 V and four NiMH give 4.8 V, so choose resistors for the voltage you will actually have.
Never mix old and new, or different types, in one holder. Check polarity before inserting.
REMEMBER
Rechargeables are 1.2 V per cell, not 1.5 V.Try it yourself
Sketch the circuit on paper first, calculate the values, then build it on a solderless breadboard using a low-voltage supply. Measure with a multimeter before you make anything permanent.
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