Power supply with LM317 Advices Needed - Part 2

Hi all,

I have a few questions - not a lot, like in earlier post ...- about schematic of " Power supply with LM317 Advices needed ".
Many, give me good replies and i appreciate...

Question 1:
Is there One GND or Two GND?
See Schematic Below.


Question 2:

It's about Output Voltage; maybe misunderstanding of KVL:

Output Voltage: 1.25*(1+(5*10³*1.5*10³)/(6.5*10³))/120 = 13.26 V DC Right or False?

Let's say 1.5* 10³=0 U3 in schematic

Output Voltage: 1.25*(1+(5*10³/120)) = 53.33 V Right?????? It seems False....



Question 3:

I really searched Google and others means, but stuck with how to get this negative voltage, for 0V LM317 OutputSo, if someone can explain me; would be great.

See image below:


4° Question:

Read in schematic, for improving Line Transient Response:

With 10mF C3 capacitor, ripple current from 4 x MBR735 Bridge, is decreased, but there's still ripple after LM317?

In short, can I add D1, C2, C3, or C4 100µF is sufficient to get a low LM317 ripple output?






5° question:

Thanks a lot and nice day too.

jm