 | ตัวอย่างการประยุกต์ใช้หลักการข้อที่ 32 เปลี่ยนสี |
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The Duracell powercheck batteries use a thin film of resistive material with heat sensitive crystals on top. By pushing the two dots, you close the circuit, and the resistive material will warm up. Depending on the temperature, the heat sensitive crystals change color. The higher the temperature, the more crystals will change color, which in turn is an indication of the power of the battery. |