Product specifications

DA100 (50Hz) and DA50W Chassis – Repair Notes
Page 28 of 80
From the primary winding (pin 7) the HT is stepped up and rectified by D621 to produce the supply required by
the CRT drive circuit. Finally a negative going voltage is fed from pin 8 to the protection circuit. This voltage
represents the beam current. The greater the beam current (raster going brighter) the greater this voltage
would be in a negative direction. This negative voltage is then fed to the IC1001 pin 95 via D622 and Q606. Once
this voltage has exceeded safe working levels IC1001 pin 95 will go low switching the television to standby (no
power supply operation).
Figure 23: Location of Horizontal Stage Components
Figure 24: Q601 Base Drive Waveform
Sharp Electronics (UK) Limited - May 2003
Revision 3