| 摘要 |
PURPOSE:To permit the accurate detection of an amt. of liquid and the reduction in power consumption by connecting trimmed fixed resistances in series to a variable resistance, making the resistance value varying with the extent of movement of a slider proportional to the amt. of liquid and correcting the variable resistance. CONSTITUTION:A variable resistance exhibiting resistance values corresponding to the amt. of liquid, and one or plural pieces of trimmed fixed resistances are connected in series on a ceramic or glass substrate. For example, when a float is at the lowermost level of a liquid tank, a slider 11 of a variable resistance 4 is located at an electrode 5, and the voltage corresponding to this is outputted from an electrode 12. Therefore, a fixed resistance 7 is so trimmed as to attain optimum values, so that a display device 14 displays the amt. of liquid correctly. When the float ascends, the slider 11 slides in the direction of an electrode 6, and similarly, a fixed resistance 7 is trimmed so as to attain an optimum value at the uppermost level. The variable resistance is formed like A-C, and has the variable change characteristics conformed to the characteristics of the liquid tank and processing circuits. |
