So i sat down to repair this desulphator and the design bowled me ...
My understanding of the operation is:
1. Mosfet turns on current ramps in both inductors
2. Mosfet turns off the inductors reverse polarity and their voltage increases to L*di/dt This causes the diode to forward bias and dump the voltage / energy back to the input
Control is through a 3845, voltage at the drain is rectified and made dc via 4934 / 47nf and 1uF then put to a TL431 operating an opto connected to the FB pin.
My question:
Couldnt the designer have removed the 220uH inductor and 470uFcap? Or is there something more to the design that i dont understand?
cant give out the entire schematic but can answer all questions ....
Thanks!
My understanding of the operation is:
1. Mosfet turns on current ramps in both inductors
2. Mosfet turns off the inductors reverse polarity and their voltage increases to L*di/dt This causes the diode to forward bias and dump the voltage / energy back to the input
Control is through a 3845, voltage at the drain is rectified and made dc via 4934 / 47nf and 1uF then put to a TL431 operating an opto connected to the FB pin.
My question:
Couldnt the designer have removed the 220uH inductor and 470uFcap? Or is there something more to the design that i dont understand?
cant give out the entire schematic but can answer all questions ....
Thanks!
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