Multiposition Optronic Switch for Electric Circuits In electric curcuits, multiposition contact switches (wafer type, bank and wipe, slide, etc. ) for control circuits with the voltage of 5 to 380 V are well known. The contact switches have a limited number (10 - 11) of positions and directions, as the more contacts are placed on one axis, the higher forces are to be applied for lever turning. The switches of these types are not destined to be installed in fire and explosion dangerous premises.

The present proposal concerns multiposition switches in which light taking photo-diodes are used instead of fixed contacts and the optic waves radiator (light diode or electric bulb in Fig. 1) is used instead of the sliding contact.

The optronic switches proposed are two - three times more reliable and simpler in design than contact ones, this being important for instruments working under field conditions. They can be manufactured for any necessary number of directions and positions, are explosion safe, have no sparkling contacts, operate under the voltage of 5 V, have no mechanical contacts, springs and are characterized by the simplicity and constant pressure on the lever irrespective of the number of circuits to be switched.



There is no necessity in applying non-ferrous metals for contact pairs (copper, gold, silver), they can be subjected to shaking, are simple in design. In case the device is to be used in a sparkle-safe design, there is no necessity in special stuffing box seals and massive bodies. Optronic switches are simpler than sensor or magnetic keys, the latter being usually not applied as multiposition ones, but only as 2 - 3 position switches.

The principle of the optronic switch operation is as follows . In cylindric lightproof glass 1 photodiodes 5 are being positioned along its perimeter, their number being equal to the number of circuits controlled. Cylinder 4 with a vertical slot or orifice is positioned in the center, along the glass axis and fixed to the switch lever 3. Light diode or fixed miniature electric bulb 6 is inside the cylinder. Lens 2 passing partly the light beams can be provided in the lever, thus facilitating the operation at night and signaling on the switch readiness for operation.

When turning the lever with a fixer, a narrow beam of light cones on one of the light diodes making it electroconductive and opening the transistor key in the scheme part controlled or in the object to be controlled.

It is possible to turn the key lever within the limits 0 through 360 degrees with reverse. In case of the electric bulb (1.5 by 5 V) lever turning can be non-reversive for any angle.

When using the radiation light diode there is no necessity in turning cylinder 4 with a slot. In this case the light diode rotates itself. The switch can be installed on aircraft and tanks control panels, at remote control boards for any objects, in radio station panels, in medical appliances, etc. The switch is simple in design, highly reliable and cost competitive. Its dimensions are proportional to the number of light diodes installed.