Service manual

The DYN-FASE-CORR signal is fed to the HOP via C2455 and drives a dynamic phase
correction necessary because of beam current variations. This is done by regulating
TON of the line transistor TS7421.
East-West Circuit
The moment TS7480 is driven into saturation, C2421 will discharge during the flyback.
As a consequence of which C2421 must be charged again during the scan via the
conduction diode D6422 (as long as C2421 is not charged to the voltage across L5422,
D6422 will conduct). The current in the deflection coil is therefore larger than the current
flowing in L5422 (1-2). The voltage across the deflection coil increases, so the picture
width increases. When TS7480 blocks, C2421 will not discharge anymore and the
voltage across C2421 will remain constant. The result is that the voltage across the
deflection coil is minimal. The voltage across coil L5422, however, is maximal. This coil
(L5422) consists of a transformer:
• As the current through the coil 1-2 increases (smaller picture width), the current
through coil 3-4 decreases. Because of the transformer characteristic a higher
voltage will be subjected to coil 3-4, this will counteract the current. The current
will diminish even further.
• When the current through coil 1-2 diminishes (larger picture width), the current
through coil 3-4 increases.
The EW Drive
The EW drive signal originates in the HOP and is supplied to TS7480. The shape of this
signal determines the various geometric correction parameters:
• H amplitude,
• EW-parabola,