Horizontal Output Transformer A flyback transformer(FBT), also called a line output transformer(LOPT), is a special type of electrical transformer. It was initially designed to generate high voltage sawtooth signals at a relatively high frequency. In modern applications it is used extensively in switched-mode power supplies for both low (3V) and high voltage (over 10 kV) supplies. It was invented as a means of controlling the horizontal movement of the electron beam in a cathode ray tube(CRT). Unlike conventional transformers, a flyback transformer is not fed with a signal of the same waveshape as the intended output current. A convenient side effect of such a transformer is the considerable energy that is available in its magnetic circuit. This can be exploited using extra windings that can be used to provide power to operate other parts of the equipment. In particular, very high voltages are easily obtained using relatively few turns of winding which, once rectified, can provide
