dc power supply analysis

i have to analyse this dc power supply given in picture. the following doubts i had encountered while analysing them :
1) why a schottky diode is used for rectifcation of dc power input?
2) what is the purpose of L300(either dc transformer or coupled inductor) and what is importance there?
3) a capacitor c312 is connected across -Vout and +vin and another -vout and -vin. what is the necessary of those and why are they rated for a voltage of 2000v
4) why 2 capacitors are used for filtering the output of pxd20. one is 100nf and other is 10uf. is it that one is used for filtering of high frquency ac component and another for a low freq dc component, if so which is used for high and low.

Here we go, doing your homework for you.

1. Low voltage drop
2. remove spikes
3. can't see C312 on diagram
4. 100n removed high freq spikes 10u removes low freq ripples.

colin55 said:

Here we go, doing your homework for you.

1. Low voltage drop
2. remove spikes
3. can't see C312 on diagram
4. 100n removed high freq spikes 10u removes low freq ripples.

Click to expand...

thnks colin for the info and regarding the c312 it is across the terminals 5 and 1 in U300 - pxd20-48so5, a dc-dc converter. it is 1nf and 2000v. is it used for any protection. if so why is it connected between negative output and the inputs? any specific reason behind it?