Abstract: A flyback converter and forward converter is described that include an input coil, a primary switch connected in series with the input coil, and an output coil magnetically coupled to the input coil. The input coil has an input side connected to an input of the circuit and a switch side connected to the primary switch. The converter further includes an input side clamp circuit, the input side clamp circuit including an energy store and a switch arrangement controlled such that the leakage inductance energy stored, in use, in the energy store, can be discharged to the input side of the input coil.

Abstract: A system of determining unknown symbols of an error correcting code using the Discrete Fourier Transform (DFT) with arithmetic corresponding to the number field of the error correcting code, including complex numbers. Encoder and decoder configurations are described. Parallel generation of independent parity check equations, simultaneous solution of unknown symbols generating, or regenerating a codeword of the error correcting code.

Abstract: This invention provides an error correction system whereby codes, including codes known to be optimum, may be concatenated together so that a longer code is produced which may be decoded by decoding the individual codes using any type of error correcting decoder including list decoders, Dorsch decoders in particular, and iterative decoders. The concatenated code consists of one or more codes having replicated codewords to which are added codewords from one or more other codes. The code construction is utilised in the receiver with a decoder that firstly decodes one or more individual codewords from a received vector. The detected codewords from this first decoding are used to undo the code concatenation within the received vector to allow the replicated codewords to be decoded. Examples of the performance benefits of the invention in comparison to the well known state of the art coding arrangement of LDPC codes, and turbo codes using iterative decoders are given for (256,128) and (512,256) codes.