Tear-Down: Let's Take a Trip Inside A UPS
Tear-Down: Let's Take a Trip Inside A UPS
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Another Classic: APC's BX1000
When power bars with surge protection are not enough, and a little security from power loss is desired, the next step up is a UPS. APC sold more than a dozen different units in this form factor under various model numbers with similar feature sets. In my case, the original retail box says BX1000, the battery compartment cover says XS1000, and the USB device identifier string says RS1000. That's a nice little chimera.
The status-and-control panel has LEDs corresponding to On-Line, On-Battery, Overload, and Replace Battery. Below those LEDs lies the single On/Off/Cold-Start button. You get little more than the essential stuff.
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I actually sent in this article two weeks ago. It just happened to finish bubbling up the editorial pipeline last weekend and get a publication slot today.
As for replacements for the good old UPS + Generator combo, I presume you mean things like the Bloom Box - basically a fuel-cell-powered UPS - removes the lead, the acid, periodic battery replacement, periodic maintenance on the mechanical parts, etc. from the equation.
Im just glad the paper is done and the UPS's we have at work dont need their batteries replaced hopefully for another few years. The ones we are using have a tray of about 20-26 batteries linked together and can make a great sparkler if the terminals make contacts to the wrong parts.
or go to your utensil draw and grab those chop sticks you've been saving!
Hollow screws? Guess I'll have to take a second look.
Even on my full-resolution originals I cannot really see inside their bore but they do look like Allen-key heads. I do not remember seeing threads in those holes but do not have clear-enough back-side shots to verify that without going back in - the unpopulated holes are clearly non-threaded. Part of the reason I thought those were rivets is head shape variations - as if they had been pressed into place. I suppose this could just as easily have been part of the hollow Allen screw forming process. Now I'm going to have to remove one of these to take a look.
When you go upscale, that's exactly what you get wit stuff like Caterpilar Power Systems 500kVA-1MVA units.
The UPS part is a flywheel motor/generator spinning in a vacuum. If the power is off longer than 30 seconds, a large diesel kicks in.
The whole thing fits in a standard 40 foot shipping container.
However, the screw's threads are heavily "beaten down" and that tells me they were used as self-tappers. Removing them pretty much ruins both whatever is left of the screw's threads along with most of the threads they formed inside the hole. If you do not want to ruin the heatsink's threads, you have to drill the head off and run the rest of the screw through. Guess that might explain why they picked hollow screws.
At that point, they might just as well be rivets.
I have seen transistors pop riveted in place many times however.
I was thinking more along the lines of press-fitted rivets: load the rivet on a hydraulic press, line it up with holes, press it in, done.
Another possibility I thought of was ram-expansion: insert a hollow rivet and ram a die through the center to lock it in place. Considering how abnormal those threads felt when I removed this "screw," I would be tempted to believe this might be how these things were set: insert the "screw" and ram a 2mm hex die through the middle to expand its threads into place instead of screwing it in.
Maybe I am just over-thinking why they used hollow screws... but I cannot help thinking there must be a reason.
today i got my ups back which service centers had replaced PCB of UPS after i inspected i was shocked they just gave me a old working unit, they just placed my unit's serial number on it and then they gave it to me. i'm seriously disappointed and i feel cheated.. i don't get it, what's wrong with these guys..
When you go upscale, that's exactly what you get wit stuff like Caterpilar Power Systems 500kVA-1MVA units.
The UPS part is a flywheel motor/generator spinning in a vacuum. If the power is off longer than 30 seconds, a large diesel kicks in.
The whole thing fits in a standard 40 foot shipping container.
The flywheel systems are nice and do handle a heavy load, they just will not replace the traditional lead-acid battery design. At this time the only system that can attempt to change that is those working with the sodium based batteries like GE. They can store the batteries outside without concern of environmental factors unlike lead acid, and they last alot longer. Office space inside a building cost a premium, storing everything outside in a utility shed costs almost nothing.
Next UPS I take apart, I will try to remember to take pictures of everything to add to this.
However, the screw's threads are heavily "beaten down" and that tells me they were used as self-tappers. Removing them pretty much ruins both whatever is left of the screw's threads along with most of the threads they formed inside the hole. If you do not want to ruin the heatsink's threads, you have to drill the head off and run the rest of the screw through. Guess that might explain why they picked hollow screws.
At that point, they might just as well be rivets.
I had an RS 1500 that just stopped working one night. After some dis-assembly and some research, it was at least one of those components that went bad. I was able to remove the screws so I could desolder all the components, think it was 6 of them. I think 2 tested out bad, but I replaced all of them, fresh thermal paste where needed and was able to screw em back onto the heat sinks.
It's still working now, 2 years later, a new set of batteries and its gotta be over 10 years old by now, I bought it used on ebay as it was.