Electrical control devices

A potentiometer, comprising a support member having first and second support regions and an intermediate region located therebetween, resistance means supported on the support member at said first support region, comprising a resistive member and a second electrode which are spaced apart from each other but, on application of pressure, come into contact with each other, and having a longitudinal dimension extending transversely of a line from the first support region to the second support region, and the potentiometer also comprising a resilient contact member secured to the support member at said second support region and extending over the intermediate region and terminating superjacent the resistance means, the contact member being flexible both about axes which extend parallel to said line and about axes which extend transversely of said line, whereby application of pressure to the contact member at a location over said intermediate region causes the contact member to bend resiliently about an axis perpendicular to said line and to engage the resistance means, and movement of the point of application of pressure perpendicular to said line causes the point of engagement of the resistance means by the contact member to move along the longitudinal dimension of the resistance means, so that when the ends of said resistive member are connected to opposite respective poles of a voltage source a voltage may be tapped off from the resistive member by way of said sensing electrode by applying pressure to the intermediate region of the contact member, the tapped-off voltage being selectively variable by varying the position along the contact member at which pressure is applied thereto.