KV-32LS65AUS (serv.man4) - Sony TV Service Manual (repair manual). Page 8

 

The oscillator voltage output at pins 12 and 16 use drivers Q6006 and 
Q6007 to develop T6002 secondary voltages.  IC6001’s oscillator will 
shut down if the driver transistor’s current is excessive. To prevent 
premature shutdown, the timer capacitor C6007 (refer to Figure2.3) 
delays the shutdown.  
 
 

Although the oscillator is running at the initial frequency of 200 kHz, 
there is insufficient current from T6002 to produce any unregulated 
output voltage because of the  load.  There is a little load on D6008 
(refer to Figure 2.3). This voltage is returned to IC6001 / pin 8 (VC1) to 
serve as regulated +B for the IC.  
 
 
 
 
 
 

At start up, IC6001 initially uses current limit +B from pin 18 to power 
internal drivers. These internal drivers amplify the oscillator signal and 
get out to pins 12 and 16.  When the power supply stage works, the 
power comes for the bottom driver, VG(L); pin 12 from pin 10 (VC2) 
and for the top driver, VG(H); pin 16 from pin 14 (VB).  The VB voltage 
is approximately +5V (average) above the reference voltage at 
IC6001/pin15. 

 

 

This voltage supplies the top internal driver that amplifies the oscillator 
signal that leaves IC6001/pin 16. The regulating stage uses error 
detector IC6003 and optical isolator PH6001 to monitor the output from 
T6002. If the output is low, the voltage fed back to IC6001/pin 2 goes 
HIGH, decreasing the oscillator frequency. The decrease in frequency 
increases the output of T6002. 
 
 

 

 
 
 

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