| 摘要 |
An electrical control device comprises a base member, and an elongate support member mounted to be movable transversely of its length with respect to the base member. A tension spring biases the elongate member against movement in one direction transversely of its length and towards a null position. An elongate resistive member is supported by and extends along the length of the support member, and when the ends of the resistive member are connected to opposite respective poles of a voltage source a sensing electrode can be applied to the resistive member to tap off a voltage which is selectively variable by varying the position along the support member at which the sensing electrode is applied to the resistive member. The resistive member is so arranged with respect to the support member that application of the sensing electrode to the resistive member tends to bring about movement of the elongate member with respect to the base member in opposition to the bias established by the tension spring. A position pick-up has a first part connected to the support member and a second part connected to the base member, and the parts are arranged and connected to generate an electrical analog signal dependent on the position of the support member with respect to the base member. The device is also provided with means for generating a predetermined response when the support member is moved from the null position through an initiating threshold position against the bias established by the tension spring and for terminating the response when the support member is returned from beyond the initiating threshold position towards the null position through a termination threshold position. |
