Variable electric capacitor

An electric capacitor comprising two electrode units, each electrode unit comprises a plurality of coaxially arranged cylindrical capacitor plates, each electrode unit having at least one capacitor plate arranged such that a plurality of capacitor plate portions with parallel mutually oppositely facing surfaces are provided, and a support for said at least one capacitor plate, said at least one capacitor plate having two oppositely positioned lateral edges, one of which is free and the other is fixedly secured to the support, a gap being defined between the oppositely facing surfaces of the capacitor plate portions, said gap being greater than the thickness of said at least one capacitor plate of the other electrode unit, the respective capacitor plate portions of the two electrode units being intermeshed and the mutually facing surfaces of the capacitor plate portions being parallel to a straight line along which one electrode unit is adjustable relative to the other for varying the extent of intermeshing of the capacitor plate portions of both electrode units, guiding means being provided at each electrode unit adjacent said support and being constituted by radially offset portions of the capacitor plates, said guiding means being arranged to engage the free lateral edge of said at least one capacitor plate of the other electrode unit for individually centering all capacitor plate portions of each electrode unit with respect to the capacitor plate portions of the other electrode unit when the two electrode units are set to a maximum extent of intermeshing of their capacitor plate portions while in other settings of the electrode units the guiding means are out of engagement with said at least one capacitor plate of the other electrode unit, each said guiding means being constituted by at least one surface portion extending in a direction parallel to said straight line.