Seasonic Platinum Series 860W - Platinum without the Fuss
by Martin Kaffei on February 24, 2012 12:00 AM ESTInternals and Electronics
As our research has shown the Platinum 860W is very close to the 80 Plus Gold X-1000 and X-1250. This is not surprising, since the earlier model PSUs already had a considerably higher efficiency than the requirements for 80 Plus Gold certification. Seasonic employs a full-bridge resonant converter that utilizes the transformer in full. You don't need any diodes for commutation during turn-off. As a result this circuit design is predestined for higher power ratings.
The current and voltage pulses of the resonant circuit run nearly sinusoidal and the transistors turn on at zero voltage. Together with the low resistance on the drain-source path the power dissipation is much lower during turn-on, turn-off, and the saturation of those transistors. Accordingly the heatsinks are much smaller now. However, differences between the larger models are the "weaker" MOSFETs and the missing third primary capacitor (which you can see a silkscreened space for in the above image).
There are some minor changes from the previous X-series. One of them is connected with the resonant circuit itself. Two conductions of the IC CM6901 (on a small PCB) lead to a small inductor, which is located between the resonant capacitor, the resonant coil, and the small "auxiliary coil" to relieve the main transformer. With this the current is measured in the resonant circuit to improve regulation. A second winding is connected to the main PCB and the magnetic flux in the core passes through the regulation winding.
We found out that there are two +12V sources at the transformer with two large ground planes. The PS232F offers over current protection for +3.3V, +5V and +12V (up to four outputs). This is the second sign that this PSU has multiple +12V outputs. The pins for the over current measurements are connected to +12V without exception. Seasonic does not officially favor a single output, but many ODM customers such as Corsair do, which might be the reason for the "single rail" rating on their label. Nevertheless it is basically a multiple 12V rail design.
Facebook
Twitter
RSS
69 Comments
View All Comments
Death666Angel - Friday, February 24, 2012 - link
I read that OCP isn't that necessary in a single rail 12V design with the 12V offering nearly the whole capacity. General overpower protection is enough there. Is that not true?Martin Kaffei - Friday, February 24, 2012 - link
Hi,if there is an overcurrent on one ouput only, the total power might be below the level for OPP.
Death666Angel - Friday, February 24, 2012 - link
So, you are saying 3V and 5V could draw overcurrents then? :P That would be a special situation in this day and age.Martin Kaffei - Saturday, February 25, 2012 - link
That won't be simple. The ouput cables are parallel-connected to 12V which means the current usually gets shared. But it might happen that a high current will flow through a single cable when resistance is low enough. E.g. an unwanted bridge between two pins.This is no short circuit since there are enough resistors (or components with resistance) between the voltage source (secondary winding) and the output. SCP doesn't work.
This is no over power since resistance is low enough that you don't need much work (voltage) to transport load carrier. Voltage will be much lower. Power is the product of voltage and current which means the total power might be below the settings for OPP, even if current is high. OPP doesn't elese.
versesuvius - Friday, February 24, 2012 - link
What is the guaranty on this power supply? 5 years? 7 years? Or just 2 years?InsaneScientist - Friday, February 24, 2012 - link
Pg 2. - Last sentence of the second paragraph:"Seasonic also provides a 7-year warranty..." ;)
versesuvius - Friday, February 24, 2012 - link
Yes, I missed that. Actually the Seasonic site is equally skimpy on this little detail as well.It would be a really good idea if Anandtech provided a spec sheet of sorts for the reviewed products so that they could be glanced for basic info. This particular review saves a lot more than that, which in the case of a "Best PSU Ever" and a Gold award, it is certainly lacking.
I searched for "guaranty" on all pages before posting. I should have searched for "warranty". Being an Iranian I always thought that they are the same, but it looks like they are the same at the same time that they are not (i.e. You take the manufacturer to court for "guaranty", and reseller or distributor for "warranty"):
http://wiki.answers.com/Q/What_is_the_difference_b...
Anyway, here is a 100 months on the spot replacement guaranty:
http://www.green-case.com/products/power/power.php...
The page says that the power is certified Platinum by EPRI-EPA, but it is sold under 80-Plus Gold. (Maybe Platinum for 230v and Gold for 110v. :) )
ProtonGuy - Friday, February 24, 2012 - link
Guarantee is the more common spelling in this day and age by the way.AnnihilatorX - Friday, February 24, 2012 - link
Seasonic always makes extremely good PSU and they haven't disappoint this time eitherI own an X-560. Before I bought Seasonic I was with Enemax.
someone need to convince me really hard not to buy from Seasonic again
entity279 - Friday, February 24, 2012 - link
Own one for 1 about month and a half. It was a (pricey) no brainer since I wanted spare power (my current sistem uses less than 400W in full load but it will be upgraded from time to time), efficiency & absolute silence. The Super Flower based alternatives were nowhere to be found in my country (Romania).So far works perfectly.