Rotation And Vertical Key Circuits; Rotation; Vertical Key - Sony CPD-420GS Training Manual

Rotation and Vertical Key Circuits

Rotation

Rotation adjustments can be made via the user OSD menu and via the
DAS Software. The Micro IC1001/3 (N Board) outputs the 'ROTATION'
PWM control waveform and is routed to the D Board. The PWM wave-
form is filtered by R729 and C705 and the DC level is applied to IC702/2
(-). IC702 current amplifies the DC level and the output at pin 4 (O) drives
the Rotation Coil via CN702. When the Rotation adjustment is performed,
the PWM duty cycle changes which results in a change of the DC level
applied to IC702/2 (-). The output of IC702/4 (O) varies from approxi-
mately +11V DC to -11V DC. The input to IC702/1 (+) is set to a DC
reference source.
· The 'ROTATION' PWM waveform controls the Rotation by varying
the duty cycle of the waveform.
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Vertical Key

The Vertical Key adjustment can only be performed via the DAS Soft-
ware. The DSP IC1002/59 (VDF2) outputs the 'D.TILT' triangle wave-
form and is routed to the D Board. The D.TILT waveform via R736 is
applied to the DC reference source, which is input to IC702/1 (+). When
the Vertical Key adjustment is performed, the D.TILT triangle waveform
varies in shape and as a result the DC reference source is varied by the
D.TILT waveform.
· The D.TILT waveform controls the Vertical Key by varying the shape
of the waveform.