Abstract: A connector comprises a sleeve and a rod, the threaded interfacing surface of one of the parts being provided with a longitudinal recess for the input of conductors. The recess has a concave surface facing the longitudinal axis of the connector and the depth thereof increases in the direction where the two parts are joined.

Abstract: An electrochrome element control device comprising a voltage source connected in parallel via a switch with a circuit composed of a series-connected electrochrome element and a capacitor for limiting the time the voltage is supplied to the electrochrome element, the charged capacitor supplies voltage of opposite polarity to the electrochrome element upon closure of a second switch connected in parallel to the circuit composed of the electrochrome element and the capacitor. Control of the electrochrome element is considerably simplified therefore.