So what needs to be actively cooled in a PSU? (#2)

Hi guys, I started a thread last year regarding the SS-5001LU PSU that I am wanting to run completely passive. (http://ift.tt/1FjfoOO)



I've now bought the PSU in question and just wanted to go over a few things just so I don't destroy the thing or kill myself in the process. I've also bought a multimeter and have learned some basic functions. I have basic soldering skills but am a novice when it comes to electricity and circuits but am actively trying to learn, so please bare with me.



From the last thread and the review on jonnyguru of the PSU I've been trying to get a grasp on the important parts of the PSU. See pic, (if I've missed anything important or labelled something wrong please let me know)







Now my questions.

• Blue: Secondary side heat sink. What exactly is it cooling and does it produce much heat?
  


• Blue: Secondary side heat sink. Appears to be grounded to the chassis of the PSU case. It actually screws into the housing and doing a continuity test with the heat sink, chassis and screw mounts all result in a beep. So this heatsink is safe, no current and is grounded?

• Red: Primary side heatsinks. These two heatsinks are isolated from the rest of the chassis and are physically shorter than the secondary side one making sure it has no contact with the housing. Will these two have current passing through them? (someone mentioned in last thread 160vdc through the primary side heatsinks is normal.

1. How do I go about to measure these heatsinks with multimeter to see if they have a live current in them? or should I just use a tester.


2. Doing a continuity test on these two heatsinks makes a circuit as got a beep when touching probe on either side. So no danger if these two heatsinks make contact with each other?

• Yellow: Main capacitors. Are these two the main / only dangerous parts in the PSU when off? and will they auto discharge when unplugged if I need to handle PSU?

• Purple: Bridge Rectifier. What does this do and is it a large heat source. It again is isolated from everything else, and is also isolated from the Primary Side heat sinks.

• What would be the main sources of heat, Mofsets?

Racap of aims of project

Quote:

Just a quick summary of what i'm trying to do in this project. I'm working on a Zalman TNN-500AF case which is completely passive. It originally come with a 400w passively cooled PSU which are pretty useless in 2015. I am wanting to, after some advice here actually, to transplant the SS-5001LU PSU into the housing of the old Zalman PSU. This is the old Zalman PSU and as you can see it is attached to a massive heatsink on the side door. Once the SS-5001LU is in the new housing its small heatsinks will all be linked up the the zalman case http://ift.tt/1ILa9VL http://ift.tt/1ILa4l2

So what needs to be actively cooled in a PSU? (#2)