This device, patented by Harold Colman and Ronald Seddon-Gillespie on 5 December 1956, is quite remarkable. It is a tiny lightweight device which can produce electricity using a self-powered electromagnet and chemical salts. The working life of the device before needing refurbishment is estimated at some 70 years with an output of about one kilowatt.
The operation is controlled by a transmitter which bombards the chemical sample with 300 MHz radio waves. This produces radioactive emissions from the chemical mixture for a period of one hour maximum, so that the transmitter needs to be run for 15 to 30 seconds once every hour. The chemical mixture is shielded by a lead screen to prevent harmful radiation from reaching the user....
This generator unit includes a magnet. a tube containing a chemcial mixture of elements whose nuclei becomes unstable as a result of a bombardment by short waves so that the elements become radio-active and release electrical energy, the mixture being mounted between, and in contact with, a pair of different metals such as copper and zinc, and a capacitor mounted between those metals.
The mixture is preferably composed of the elements Cadmium, Phosphorus and Cobalt having atomic weights of 112, 31, and 59 respectively. The mixture, which may be of powdered form, is mounted in a tube of non-conducting, high heat resistivity material and is compressed between granulated zinc at one end of the tube and granulated copper at the other end, the ends of the tube being closed by brass caps and the tube being carried in a suitable cradle so that it is located between the poles of the magnet. The magnet is preferably an electromagnet and is energized by the current produced by the unit. The transmitter unit which is used for activating the generator unit may be of any conventional type operating in the ultra-shortwave band and is preferably crystal-controlled at the desired frequency with the necessity of tuning. The quartz tube containing the chemical mixture, works best if made up of a number of small cells in series. In other words, considering the cartridge from one end to the other, at one end and in contact with the brass cap, there would be a layer of copper powder, then a layer of the chemical mixture, then a layer of powedered zinc, a layer of powdered copper, etc., with a layer of powdered zinc in contact with the brass cap at the other end of the cartridge. With a cartridge some 45 mm long and 5 mm diameter, some 14 cells may be included.