Miniature cells and batteries

Chapter Miniature cells and batteries

Teach Yourself Electricity and Electronics Third Edition Book
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Teach Yourself Electricity and Electronics Third Edition Book

  • Band (CB) or ham radio. They’re also good for scanner radio receivers in portable loca-tions, for camping lamps, and for other medium-power needs.Miniature cells and batteriesIn recent years, cells and batteries—especially cells—have become available in many dif-ferent sizes and shapes besides the old cylindrical cells, transistor batteries and lantern bat-teries. These are used in watches, cameras, and other microminiature electronic gizmos.Silver-oxide typesSilver-oxide cells are usually made into button-like shapes, and can fit inside even asmall wristwatch. They come in various sizes and thicknesses, all with similar appear-ances. They supply 1.5 V, and offer excellent energy storage for the weight. They alsohave a flat discharge curve, like the one shown in the graph of Fig. 7-3. The previouslydescribed zinc-carbon and alkaline cells and batteries have a current output that de-clines with time in a steady fashion, as shown in Fig. 7-5. This is known as a decliningdischarge curve.124 Cells and batteries7-5A declining discharge curve.Silver-oxide cells can be stacked to make batteries. Several of these miniature cells,one on top of the other, might provide 6 V or 9 V for a transistor radio or other light-dutyelectronic device. The resulting battery is about the size of an AAA cylindrical cell.Mercury typesMercury cells, also called mercuric oxide cells, have advantages similar to silver-oxidecells. They are manufactured in the same general form. The main difference, often not ofsignificance, is a somewhat lower voltage per cell: 1.35 V. If six of these cells are stacked