|A member of the Funky Media Group|
|Review: OCZ ZT Series 650W Power Supply|
|Posted by Ed Smith|
|Tuesday, 24 April 2012 03:51|
Page 7 of 9
Dissection and Inspection (Part I)
If that isn't enough for you, OCZ has a word for you in the ZT Series 650w PSU's manual:
With that out of the way I'll get the PSU's cover and fan out of the way, in the process a quick fan hub picture:
0.7 A is a decent chunk of juice, this thing definitely moves some air. Now we can see the unit's guts!
What do we see? A few things actually. One is that this is not a DC-DC unit, but it is indipendantly regulated. This explains the 12 V ripple test results. Also visible is a bit chunky bus bar connecting the main PCB's ground to the modular output board. Below it is a similar bus bar for 12 V. On the plus side this makes for an excellent connection and nice low resistance. On the minus side it makes it harder for my to get pictures. Oh well.
From this point we're going to follow the mythical power beast through the unit, this means we start at the receptacle for some transient filtering.
One X capacitor, two Y capacitors and a ferrite bead on the wires between here and the PCB. We also see some rather nice soldering here, whoever OCZ has doing this did a good job.
Here we have the rest of the transient filter, there is a fuse on the right, then an inductor, an X cap and two Y caps and a second inductor to round things out. On the far left we see the bridge rectifiers and one of the two X caps on their output legs. Diodes are quite noisy when they switch, so OCZ included a pair of X caps to smooth that noise out.
Notably lacking is a MOV or TVS diode for surge protection. Be sure to use a power strip with a surge protector built in! Admittedly modern APFC units can smooth out a decent bit of surge, but I still like to see a MOV or TVS diode.
We have two of these T10KB60 units, each rated at 10 amps and 600 volts. That's 2400w of rectification, I think that ought to be enough. Really what OCZ is doing is increasing the efficiency by splitting the load between the two rectifiers.
After being rectified the APFC unit takes over and boosts the voltage to somewhere in the high 300s. It does this with the boxy inductor you can see in the overview and two of these MOSFETs:
That's one of the two 24N50 MOSFETs, rated at 500 volts and 24 amps. Then there is a BYC8600 diode rated at 600 volts and 8 amps:
You can also see the side of the inrush protection thermister.
Once boosted the APFC stores the power in this character:
I think this is the first time I have seen Teapo refered to as a premium capacitor brand. It is 105c rated however, and Teapos work great for SMPS PSUs. It's when they are misused in CPU power modules that issues arise.
This PCB and IC are in charge of the APFC as well as the PWM that comes next:
550w, 650w, whatever. The PCB is the same for all the ZT series units.
Once there is plenty of power in the cap the CM6800 lights off a pair of 20N50 MOSFETs that run power through the main transformer.
As it comes out of the transformer the AC is rectified into 12 V by two M6020AP MOSFETs (unknown specs) and two 60L60 schottky diodes (oddly I cannot find a datasheet for these, going by the part number I'd guess 60 V and 60 A). 5 V is done via two 30L45CT schottkys (30 A, 45 V) and 3.3 V is done with a pair of 20L45CT shottkys (20 A 45 V).
As you can see the inductors, wires and transformer block any hope of getting a picture of the 12 V, 5 V or 3.3 V schottkys.
Rubycon caps for the output filter, those I think most people would agree really are premium capacitors.