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Sunday, 26 August 2018

STANDEBY SUPPLY +3VALW AND +5VALW IN CQ40

Voltage Generate +3valw and +5valw in cq40 standby supply

                                After  +3vl  drive the EC there is ACIN signal from  lm393 is go to EC on pin no.127. It let EC know the ac adapter is plugged in and EC stop the ACOFF signal out from it. ( note: when adaptor pulled out ACOFF signal makes high and tell the system adaptor  not plugged in or AC system is OFF)




When ACOFF Signal Stops Schmitt-trigger inverter PU302  pin no.2 input is low and it invert  the Signal to output on pin no.4 and make it high 3.3v (it Work here like not gate) .


 after getting high input on gate of PQ308 mosfet it ground the drain Voltage which is coming from VL through PR313 resistance. by this both gate voltages of PQ305 and PQ306 go to 0 volt or disable so the ENTRIP1 and ENTRIP2 make high and it enable the pwm signal output to DRBH1, DRVH2 ,DRBL1 and DRVL2  by which +3valw and +5valw generates  on  PL303 and PL302.



VBST1 and VBST2 give extra charge and stability to output supplies .