Abstract: A multiple range variable resistor and potentiometer suitable for use in the repair or manufacture of hearing aids and other miniature applications is disclosed. The user of the device can select the desired resistance range thereby allowing one component to be used in many different applications and reducing inventory requirements. It provides increased resistance to contamination of the internal components compared to conventional hearing aid volume controls and is not damaged by over-turning of the control knob in either direction. It can be manufactured for the same cost as conventional single range potentiometers.

Abstract: A parachute control apparatus for enabling control of an unmanned slave parachute from a manned simultaneously descending parachute is described. The apparatus includes two hand held master controllers each comprising a body and a thumb operable reciprocating plunger. The plunger is coupled to a potentiometer to provide proportional control. The parachutist carries a radio transmitter including an encoder responsive to the plunger movements and an antenna. A control signal receiver is attached to the load carried by the slave parachute and includes a receiving antenna and signal decoder operative to provide drive signals for a slave parachute control line drive. The drive includes a servo system, electric motors, gearboxes and winches for operating the slave parachute control lines.