The present invention relates to a circuit arrangement for providing a saw-tooth current waveform, with trace and retrace (flyback) interval, in a deflection coil, in which the amplitude of the said current is affected by a modulation signal. Such a circuit arrangement may be used in a colour-television kinescope horizontal deflection coil circuit and may comprise, in addition to the said deflection coil, a first retrace capacitor and a first trace capacitor which, together with the deflection coil, form a first oscillating circuit during the retrace interval, a second inductance coil, a second retrace capacitor and a second trace capacitor which form a second oscillating circuit during the retrace interval, a controllable switch connected to a power supply source through a third inductance coil and having a control electrode connected to a periodic signal source for making the controllable switch conductive during a second part of the trace interval, and a first diode and a second diode, connected in parallel with the first and second retrace capacitors, respectively, the polarity of the diodes being such that they are made conductive by current flowing in the deflection coil and in the second inductance coil, respectively, during the first part of the trace interval.
A circuit of this type is described in Italian Pat. application No. 69821-A/76, filed by the present applicant, and is designed, in particular, for providing a line deflection and a modulation circuit (or cushion distortion correction circuit, as it is also called) in the E-W direction on a colour television, in particular, on a set with a 3-in-line-gun mask-type kinescope (cathode ray tube).
The circuit described in the above patent application does not include devices for stabilizing horizontal deflection amplitude.