Rotational speed transducers
AssigneeAssociated Engineering Limited
InventorNorman Hunt
Life of this patent
Estimating the term…
Abstract
A rotational speed transducer comprises a member which is mounted to rotate at a speed related to a rotational speed input. A lamp and a photocell are mounted in relation to the rotatable member such that light from the lamp is only reflected by the rotatable member toward the photocell each time a reflector portion or portions of the rotatable member comes into a particular position or positions with respect to the lamp so as to provide an electrical output, from the photocell, which is a measure of the rotational speed input. The reflector portions may be portions of a disc which constitutes the rotatable member.
Claims2
A rotational speed transducer comprising:
- rotatable means;
- means mounting said rotatable means such that it can rotate at a speed related to a rotational speed input;
- said rotatable means having a plurality of light reflector portions;
- means mounting said plurality of reflector portions at an angle to the axis of rotation of said rotatable means;
- lamp means for emitting light;
- photocell means for receiving light from said lamp means and providing an electrical output in response thereto;
- and means mounting said lamp means and said photocell means in relation to said rotatable means whereby to reflect light emitted by said lamp means from a first reflector portion to a second reflector portion and from said latter portion to said photocell means each time said first reflector portion comes into a given relation with said lamp means, as said rotatable means rotates, thereby to provide from said photocell means an electrical output which is a measure of the rotational speed input.
Dependencies are inferred from the claim text.