| 摘要 |
<p>The device is designed to be housed in the space occupied by a control knob. It comprises two coaxial ratchet wheels (7, 8) assembled so that their circularly disposed internal teeth face in opposite directions. Each ratchet wheel has an associated contact strip (4, 5). The contact strips are driven on rotation of the knob (1) by means of a mechanical spindle (2, 10, 11) on which they are friction mounted. In one direction of rotation of the spindle, one of the strips slides over the teeth of the ratchet wheel with which it is associated, creating intermittent interruptions in the electrical contact between strip and wheel on passing from one tooth to the next. During this time, the other strip is blocked by the teeth on the associated ratchet wheel and slides around the spindle, maintaining permanent electrical contact with the ratchet wheel with which it is associated. If the direction of rotation is reversed, the functioning of the strips is also reversed. Application is found in the creation of pulses by intermittent interruption of a DC voltage as a result of the action of the strips and the descrimination of the direction of rotation of the spindle.</p> |
