GB256324A - Improvements in variable condensers - Google Patents

Abstract

256,324. Aspden, R. L. May 7, 1925. Condensers, variable, have the fixed movable plates formed with gaps or slots and tongues so co-operating that they come into alignment more than once in a half turn so that changes from maximum to minimum capacity are correspondingly frequent. Fig. 1 shows the improved condenser f coupled with an ordinary condenser e for tuning two circuits from one control member, a, e being fixed, and b, d moving, plates. As shown in Figs. 3 and 4, the plates c have tongues g and the plates d have slots h, 12 in number, but this number may be varied to suit requirements. The -hole i through the fixed plates is larger than the centre j of the moving plates, and the diameter of the slots between the tongues g is larger than the overall diameter of the moving plates. The condenser e is actuated by a spindle m and. the latter is geared through gearing n, o, p, q to the sleeve r which carries the plates of condenser f, the gearing being speed-increasing and made, for instance, of vulcanite or like insulation. As shown, one turn of the plates c changes the capacity of condenser f from minimum to maximum twelve times and, with a gear ratio of 1 : 12, for a half turn of condenser e the condenser f will change in capacity from minimum to maximum 72 times, thus making it possible to get approximately accurate tuning of two condensers by operating one control which may be on the spindle m or sleeve r. A knob s and finger t moving over a scale are fitted on the sleeve, and instead of plates c, d coaxial tubes with longitudinal slots and tongues may be used. According to the Provisional Specification, the fixed and moving elements are subdivided into a number of parts which are connected together or insulated from one another according to the purpose for which the condenser is designed. It is also stated that the moving elements, three in number and in the form of discs, have 45 teeth cut around their periphery and are located on a square shaft with the teeth in line. The fixed elements are five in number and also have 45 teeth on their periphery.