Before we take a closer look at the guts of the EX1000, here's a fan shot for all you fan lovers out there. Here... let me put on some Marvin Gaye and dim the lights a little. Have fun, kids.
Yes, I know I have a sick mind. That's what the lady in the park said, anyway.
Popping off the cover, it becomes apparent who the OEM is for the EX1000... Andyson International. Man, that's a cluttered looking design. Let me get out the soldering iron here, and I'll get to work.
Often, the AC receptacle of a power supply will hold some of the transient filter components. This one only gets a single X capacitor.
Looking at the underside of the unit, I saw a soldering job that I would only classify as so-so. It's functional, but there were several places where component leads weren't quite sheared off and traces that had the enamel scraped away.
Zooming in, we see the PWM chip of the unit itself, an NCP1395 variant resonant mode controller. Ah... that's what frequency conversion is... it's just another name for a unit that uses more than one switching frequency, varying it according to load.
From the looks of the back of the standby board, we're dealing with the Andyson AD-MT9 platform here.
And it looks like Andyson knows about the ripple issues on 12V2 and 12V3, because they tried to address it using a combination of 220uF and 0.1uF capacitors soldered to the back of the board. You know... I wonder what would happen if the capacitance were increased. I think I'm going to give that a try before I get to the scoring on page five.
In addition to the one X capacitor I mentioned earlier, the transient filter is completed at the bottom of this picture by a MOV, two coils, two more X capacitors, and four Y capacitors. Not bad at all.
Those big primary capacitors are Nichicon, by the way.
Secondary capacitors included these two polymer Nippon Chemi-Con capacitors on the 12V. The rest of them were Nippon Chemi-Con electrolytics. And yes, the unit does appear to run the 3.3V and 5V rails from the 12V output.
This is the primary heatsink. On the left are the two main switchers, W25NM50N's, and they're located right there next to the 12V2 and 12V3 modular connectors. Hello, cause of massive ripple inducing interference. The PFC parts are on the right, and consist of one diode and two 32N50C3's.
On the secondary side, the 12V output is done through synchronous rectification using six L3705Z's. The 3.3V and 5V rails each get one 125N2RG and one FDP8896.
Ok, now we're going to find out if additional capacitance can solve the ripple issue on 12V2 and 12V3. I've taken two of these here Nippon Chemi-Con KZE parts, rated at 2200uF, and crammed them into the ends of the modular cables. And now, to rerun test five:
Oscilloscope Measurements - BFG EX1000 Capacitor Mod
Wowzers! Not only have they tamed the ripple handily, those two rails are now outperforming 12V1 and 12V4 at 60mV. There you go, Andyson. You now have a solution for 12V2 and 12V3 handed to you... all you need to do is implement it and tame the 5V and 3.3V rails. Get to it. BFG deserves all the performance this platform is capable of, but is not currently getting.
Folks, I'd almost settle for these two capacitors getting kludged onto the ends of the modular cables themselves and covered with ugly shrink wrap if it meant knowing that the ripple suppression was now better than the hardwired cabling.
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