Abstract: A holder for dry-cells, for example for use in an electrical re-charging unit for dry-cells, has locating means for a dry-cell or a line of dry-cells disposed end-to-end in electrical series, and electrical contacts for the base and central electrode of the dry-cell or, where there is a line of dry-cells, of the two endmost dry-cells respectively, the first contact being radially offset so as not to make contact with the central electrode of a dry-cell which is placed the wrong way round in the locating means. In a preferred arrangement the locating means is in the form of a channel with steps in its sidewalls so as to provide pairs of shoulders which will support different diameters of dry-cells at different levels; in this arrangement the offset first contacts for all the sizes of cell are rigidly interconnected and the second contacts for all the sizes of cells are rigidly interconnected.

Abstract: A control circuit for a battery-operated fluorescent lamp has a transistorized inverter which acts as a blocking oscillator. Lamp intensity is controlled by applying an adjustable bias, either automatic or manual, to the base of the blocking oscillator transistor.