| 摘要 |
898,625. Valve sawtooth circuits. PHILIPS ELECTRICAL INDUSTRIES Ltd. sept. 25, 1959 [Sept. 30, 1958], No. 32687/59. Class 40(6). In a deflection circuit, particularly for horizontal deflection in television receivers having wide-angle cathode ray tubes, the two HT boost capacitors 11, 12 are connected in series with the primary winding of the deflection transformer 4, the deflection coil 6 being connected to part of the transformer windings including only one capacitor 12, the value of the capacitors being such that they develop equal and opposite parabolic voltages so that an S-shaped current is obtained in the deflection coil 6 but the effective boosted anode voltage is constant. An additional winding 10 may be used to provide a balanced output, thus minimising radiation from the deflection circuit. A pulse waveform from winding 15 may be used to suppress the beam during flyback. Expressions are given for the ratios of capacitors 11, 12 in terms of transformer turns ratios. Valve 1 may be replaced by a transistor. |
