Philips 7629 Service Manual page 75

A line, written at the upper- or lower side of the screen, will be larger at the screen
center when a fixed deflection current is used. Therefore the amplitude of the deflection
current must be increased when the spot approaches the center of the screen. This is
called the East/West or pincushion correction.
The 'Ew drive' signal from pin 15 of IC 7200 takes care for the correct correction. It
drives FET 7400.It also corrects breathing of the picture, due to beam current variations
(the EHT varies dependent of the beam current). This correction is derived from the
'EHT information' line.
Two protections are built-in for the E/W circuit: over-current and over-voltage protection.
See paragraph 9.3.5.
Panorama
The panorama function is only used in 16:9sets. This is a function to enable the 4:3 and
Super-Wide feature. It drives the 'Bass_panorama' line, to activate relay 1400. When
this relay is switched on, the capacitors2453//2454 are added in parallel to the default
S-correction capacitors 2456//2457. This results in an increased capacitance, a lower
resonance frequency of the line deflection coil and the S-correction capacitors and
therefore a less steep S-corrected line deflection current.