GB1174164A - Electrical devices for measuring displacement - Google Patents

Abstract

1,174,164. Measuring displacement. RANK ORGANISATION Ltd. 18 April, 1988 [18 April, 1967], No. 17799/67. Heading G4H. In a positioning system of the type in which a signal representing the position of a member is compared with a reference signal, the amplitude of which represents the position of a multiposition switch, a zero offset is introduced. In one embodiment (Figs. 1-3, not shown), the stator contacts (23) of rotary decade switches are connected to the reference signal generator, preferably a series of auto-transformers, each switch having one normally energized pointer (20) and a second pointer (24) displaced by one digit from the first and energized when a carry is transmitted from the next lower decade. The stator can be rotated by an offset control knob (26) to give the required zero offset. In the embodiment of Fig. 4, the zero offset is set up on 4 pole 10-way switches 33, a contact 35 being positioned in accordance with whether a + ve orve offset is required. A relay contact 36 is operated when a carry is transmitted from the next lower decade. The reference value is entered by energizing the contacts associated with the appropriate digits of 11 pole 10-way switches 30 so that one output lead 12 of each decade switch 30 is energized to give the sum or difference of the reference and offset values, any carrier energizing relays 32.