Improvements to combined power supply and horizontal deflection devices in a television receiver.According to the invention, the line transformer includes a winding W.sub.1 for maintaining an oscillation circuit including the deflector Ly of the cathode-ray tube and a winding W.sub.2 which may be connected to a power supply source E through a controlled switch I.sub.2 ; the winding W.sub.1 is not effectively put into service for the sweep until a switch I.sub.3 or I'.sub.3 using a diode D'.sub.3 with a relatively long recovery time and operating in phase opposition with respect to I.sub.2 is closed, so that the temporary short-circuit of winding W.sub.1 during a sweep trace is not felt by the power supply source E.The invention mainly permits powering all the circuits of a television set from a single transformer, the line transformer.