Vertical deflection circuit for TV receiver - derives precisely shaped and phased blanking pulses from flyback pulses

摘要

The vertical deflection circuit, for a television receiver, obtains its blanking pulses from the shorter flyback pulses and imparts a precise shape, duration and phase to these pulses without involving the disadvantages of normal RC circuits. The output of a first diff. amp. acts as blanking pulse. One input of a second diff. amp. is connected to a capacitor and its second input is connected to a higher reference voltage than the input of the first amp. This higher ref. is reduced at the end of the charging process such that the leading edge of the output pulse of the second amp. coincides with that of the first amp.