Abstract: Position indicating device for producing an indication of the position of a displaceable structure, the device including:a plurality of sensing elements extending along a defined path such that each element is associated with a respective location along the defined path, each element being operative to respond to the presence of a position representing member when the member extends from a starting point to the respective location associated with that element, the elements being coupled into respective pairs of elements, with each pair of elements having an output producing a signal only when a single element of its respective pair is responding to the presence of the member; a plurality of signal producing members each operative for producing a signal representing a predetermined logic state in response to a predetermined input signal; and circuit components operatively connecting the outputs to the signal producing members for causing a signal at each output to produce a predetermined input signal at a corr