| 摘要 |
PURPOSE: A touch switch is provided to know the sequential contact state when the touch switch contacts another object with a sequential On/Off of the multiple switches generating a constant current. CONSTITUTION: The touch switch includes a switching unit(10) and a constant current generator(20). In the switching unit(10) multiple switches(S1-S3) each having a resistant(R1-R3) are connected in parallel. The both terminals of the switches(S1-S3) are connected to positive and negative electrodes on both sides. When the touch switch contacts another object, the switches(S1-S3) turns On/Off sequentially and produce electrical signals corresponding to the resistances(R1-R3). The constant current generator(20) connects the base to the positive electrode of the switching unit(10). The emitter terminal is connected to the negative terminal of the power supply(V). The collector terminal is connected to the negative electrode of the switching unit(10). A DC source(C) comes between the base and the emitter. The constant current generator(20) generates a constant current responding to the On/Off of the switches(S1-S3).
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