| 摘要 |
<p>The convergence circuit, for an inline colour television receiver, is an extension of existing circuits with toroidal coils and sawtooth current correction and includes the ability to eliminate asymmetric errors. The toroidal coils around the tube's neck are supplied with a line-frequency sawtooth current for correction of dynamic horizontal convergence residual error, and this correction current can be adjusted in amplitude and polarity. The coils are also supplied with an extra line-frequency parabolic current adjustable in amplitude and polarity to eliminate the asymmetric errors. The peak of the parabolic lies at the centre of the line sweep period and is clamped at a fixed value. A variable-amplitude parabolic voltage is added to its own rectified value.</p> |
