oa Cobalt-Platinum Rotors for Small Synchronous Devices

The unique magnetic properties of the cobalt-platinum alloy Platinax II enable small permanent magnets to be made which will produce a high magnetic flux across a large air gap. A small cylinder of this alloy magnetised across its diameter, produces a two pole magnet with an ideal field geometry for the rotor of a synchro-transmitter. Used in conjunction with Hall effect elements the design of such devices can be simplified as the need for windings of very fine insulated copper wire on laminated rotors, used in conventional motors, is eliminated. The increasing demand for miniaturisation of electronic components may make it necessary to reduce still further the size of servo components, and the ductility and machining properties of cobalt-platinum make it an ideal material from which to make the permanent magnet rotors.