This is not an online unit. It does do AVR, basically it maintains output using different taps on a transformer to buck/boost irregular voltage to a certain degree (I think its +/-30V), but once it goes out of that range it switches to battery. It doesnt do frequency stabilization but honestly how many of us live where the power is that unreliable? Any significant frequency deviation would start kicking off protection systems in the grid before it would affect anything at your end. I've had this thing for 8 years, and it has never let me down, never lost any equipment connected to it. Granted I dont have $30k worth of servers running on it, but it suits my needs.
Anyone know how to repair a UPS?
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That's basically what a PicoPSU does. However they dont make them over a few hundred watts. You cant really have anything simplistic like you suggest though because todays computers lean much more heavily on the 12v rails, and once the battery starts draining it will go out of spec very quickly. Tolerance on the 12v rail is 5%, so it can only go down to 11.4v before shutting down. I'm not 100% sure on the Pico's theory of operation but I'd imagine it is boosting the input before regulating it down to the different required voltages
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J Sigmo
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I, too, prefer a higher wattage soldering iron that is temperature-controlled. It is much better to have more power available than too little. Again, the key is "temperature-controlled". I can put very fine tips into my 40-Watt irons if need be. But again, I prefer to use the largest tip possible, because I get faster heat transfer. A too-small tip impedes heat flow, and that means roasting on things for too long, which is hard on components and boards.
True UPSs are supposed to have their inverters On-Line at all time. That's the only way the power can truly be "uninterrupted". Except for one exception I've found, and I can't even say they're available anymore.
A place called "Best Power" used to make UPSs that employed a ferroresonant transformer to provide voltage regulation to the load most of the time, and then a Backup Power system that switched on, in synch with the mains voltage, in the event of a power failure or anomaly beyond what the ferroresonant transformer can handle. The switchover was fast enough, and synchronized, such that there was no interruption or discontinuity in the output waveform. Thus, you got the efficiency of a back-up power unit and the true uninterrupted waveform to the load of a true UPS.
And as for UPSs providing good protection, I remember back in the early 1980s having to repair three 2.2KW Sola UPSs that all failed from a power surge at a customer's location. It was super-ironic that they didn't have as much as an MOV across their input lines!
These were big bruisers. They weighed around 150 lbs with their battery packs in place.
They all had fried power transistors, and these were amazing devices. They were in TO-3 cans, but had leads that looked like12 Gauge! 600V, 50 Amp rated bipolar darlingtons. They were complimentary, like the output of a big class A-B audio amp. I replaced 30 or 40 of them in those three units.
I also installed big (V130HE150) MOVs in the front ends, and we never had another failure in any of them.
So the amazing and ironic thing was how the manufacturer had failed to take a simple step, adding just one cheap component, to protect a device whose job it was to protect other devices from crappy power!
And these were UPSs, which, at the time, cost several thousand dollars apiece! No excuse, IMO.
As for real on-line backup, the phone company used to be fantastic about that. They simply had 48V banks of "glass-jar" lead-calcium batteries that directly sourced the network's power. Simple and extremely reliable. And they charged these batteries properly, providing periodic equalization charges, either manually or automatically. This is something I don't see in any of the standard inexpensive backup power systems that we are sold as consumers. They, Ma Bell, got lives of 50 to 100 years from their battery cells.
Where I worked back then, we got 15 to 20 year lives from sealed lead acids because we made our own power supplies, and simply paid proper attention to charge voltage. Most home and office UPSs do well to get 3 years of life from those same batteries because they just don't care, I guess. It's not that hard to properly charge lead acids. But you almost never see it done. I think it's done poorly on purpose to sell new batteries and entire backup supplies.
True UPSs are supposed to have their inverters On-Line at all time. That's the only way the power can truly be "uninterrupted". Except for one exception I've found, and I can't even say they're available anymore.
A place called "Best Power" used to make UPSs that employed a ferroresonant transformer to provide voltage regulation to the load most of the time, and then a Backup Power system that switched on, in synch with the mains voltage, in the event of a power failure or anomaly beyond what the ferroresonant transformer can handle. The switchover was fast enough, and synchronized, such that there was no interruption or discontinuity in the output waveform. Thus, you got the efficiency of a back-up power unit and the true uninterrupted waveform to the load of a true UPS.
And as for UPSs providing good protection, I remember back in the early 1980s having to repair three 2.2KW Sola UPSs that all failed from a power surge at a customer's location. It was super-ironic that they didn't have as much as an MOV across their input lines!
These were big bruisers. They weighed around 150 lbs with their battery packs in place.
They all had fried power transistors, and these were amazing devices. They were in TO-3 cans, but had leads that looked like12 Gauge! 600V, 50 Amp rated bipolar darlingtons. They were complimentary, like the output of a big class A-B audio amp. I replaced 30 or 40 of them in those three units.
I also installed big (V130HE150) MOVs in the front ends, and we never had another failure in any of them.
So the amazing and ironic thing was how the manufacturer had failed to take a simple step, adding just one cheap component, to protect a device whose job it was to protect other devices from crappy power!
And these were UPSs, which, at the time, cost several thousand dollars apiece! No excuse, IMO.
As for real on-line backup, the phone company used to be fantastic about that. They simply had 48V banks of "glass-jar" lead-calcium batteries that directly sourced the network's power. Simple and extremely reliable. And they charged these batteries properly, providing periodic equalization charges, either manually or automatically. This is something I don't see in any of the standard inexpensive backup power systems that we are sold as consumers. They, Ma Bell, got lives of 50 to 100 years from their battery cells.
Where I worked back then, we got 15 to 20 year lives from sealed lead acids because we made our own power supplies, and simply paid proper attention to charge voltage. Most home and office UPSs do well to get 3 years of life from those same batteries because they just don't care, I guess. It's not that hard to properly charge lead acids. But you almost never see it done. I think it's done poorly on purpose to sell new batteries and entire backup supplies.
Much of what you said above is very true. It is a sin to expect quality in anything nowadays. Starting with very poor manufacturing, and assembly done without any care or attention to detail, no wonder it is a surprise if it works at all.
tangent
IPCT Contributor
- May 12, 2016
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Par for the course when you deep discharge undersized batteries and don't want to spend the extra $10-20 it would take to make a better charger.
Yeah, deep discharge on the batteries is killer, even "deep cycle" batteries don't like it much at all. Heat too, way worse than cold for longevity.
Did ya'll see the new lithium iron phosphate drop in replacements for lead acids? Theres a 12v 10Ah (same size as 7Ah SLA) that can deep cycle 2000 times for $100 a piece. You can even get a 24V 260Ah pack good for 3000+ deep cycles for only $6500!
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That type has been hot topic on a motorcycle forum I visit. But, given I'm still on the original battery in my 2008 VN2K, I haven't yet seen the value in them over plain old lead-acid/AGM type. There was a hiccup last year in one start so it wouldn't surprise me if the battery pukes this year. 11 years though is a damn good run in my book.
NoloC
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I remember those Best ferroresonant POS things. We had 3 of them 10kw each. Horrible and most of the Engineers were convinced they created more problems than they solved. Best thing I ever did for that facility was shitcan them and put in an Eaton. But it was about $400K.
Also not sure what you meant about on-line UPS availability, but they are not extinct. Still the gold standard if you have the bucks. CyberPowerSmart App Online Series 2U Rack/Tower UPS (3000VA / 2700W)
J Sigmo
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It sounds like all of your experiences are about the same as mine have been.
I never tried the Best UPSs. I just remember their hype. It sounded good, and the brochures were quite alluring!
What I meant was that I wasn't sure if that company still exists, or those ferroresonant transformer-based UPSs, in particular.
We never used them because a lot of the places where we might have wanted them ran on "Rig Power" at drilling locations, and the variations in line frequency was not acceptable to a ferroresonant transformer. They liked to fail when fed power not at exactly 60Hz.
Regular back up power supplies with the tap-switching approach to voltage regulation actually worked pretty well in those situations.
So the Best units sucked, eh? Glad I never tried them, but it seemed like a good concept. But they were pretty expensive compared to typical backup power units.
Certainly true on-line UPSs do exist. They are a lot more expensive and less efficient, but whan reliability is the primary concern, you just have to spend the bucks, I guess.
You guys are all right about deep cycling lead acids. That's really their main enemy. But if you're willing to let the load lose power when the battery is too low, you can design in a low-battery disconnect to prevent that, too. Outfits like PowerSonic have some great literature describing the end-voltage versus load current and temperature so you can make the decision of what to call "too low" in any given situation. and they also describe temperature versus charge voltage, and proper float and bulk charge rates and voltages. So you really can build a battery-friendly system if you want to.
I always figure if I get 7 years from a car or motorcycle lead-acid, I've gotten my money's worth. But for SLA/AGMs in a controlled setup, we always got 10 to 20 years out of them.
But the Consumer-grade backup power supplies I've had over the years seem to kill off their batteries in about 3 years. That always makes it seem like they're just not trying. But they probably figure a large number of customers will just buy a whole new UPS, so it really is a good thing from the manufacturer's point of view. People just accept that three years is good, and hopefully buy a new unit after that.
And like you say, heat is not good! But at least if you adjust the charge voltages to account for the change in cell voltage with respect to temperature, you can protect somewhat there, too. Good charge/discharge managers do use temperature sensors.
But really high temperatures are always going to take a toll. I'm actually always amazed at how well car and truck batteries do. That is a nasty environment.
I never tried the Best UPSs. I just remember their hype. It sounded good, and the brochures were quite alluring!
What I meant was that I wasn't sure if that company still exists, or those ferroresonant transformer-based UPSs, in particular.
We never used them because a lot of the places where we might have wanted them ran on "Rig Power" at drilling locations, and the variations in line frequency was not acceptable to a ferroresonant transformer. They liked to fail when fed power not at exactly 60Hz.
Regular back up power supplies with the tap-switching approach to voltage regulation actually worked pretty well in those situations.
So the Best units sucked, eh? Glad I never tried them, but it seemed like a good concept. But they were pretty expensive compared to typical backup power units.
Certainly true on-line UPSs do exist. They are a lot more expensive and less efficient, but whan reliability is the primary concern, you just have to spend the bucks, I guess.
You guys are all right about deep cycling lead acids. That's really their main enemy. But if you're willing to let the load lose power when the battery is too low, you can design in a low-battery disconnect to prevent that, too. Outfits like PowerSonic have some great literature describing the end-voltage versus load current and temperature so you can make the decision of what to call "too low" in any given situation. and they also describe temperature versus charge voltage, and proper float and bulk charge rates and voltages. So you really can build a battery-friendly system if you want to.
I always figure if I get 7 years from a car or motorcycle lead-acid, I've gotten my money's worth. But for SLA/AGMs in a controlled setup, we always got 10 to 20 years out of them.
But the Consumer-grade backup power supplies I've had over the years seem to kill off their batteries in about 3 years. That always makes it seem like they're just not trying. But they probably figure a large number of customers will just buy a whole new UPS, so it really is a good thing from the manufacturer's point of view. People just accept that three years is good, and hopefully buy a new unit after that.
And like you say, heat is not good! But at least if you adjust the charge voltages to account for the change in cell voltage with respect to temperature, you can protect somewhat there, too. Good charge/discharge managers do use temperature sensors.
But really high temperatures are always going to take a toll. I'm actually always amazed at how well car and truck batteries do. That is a nasty environment.
Couple years back I purchased a power conditioner that has the tap switching type of AVR. After the fact I found out the tightest regulation setting was +/-5% (which isn't too bad, in itself). But, the mains voltage here is so stable that aside from a rare complete outage, I only ever heard it kick into AVR mode one time and that was just for a moment.
Moral of the story is if looking for voltage regulation and wanting something that holds spot on, so to speak, be sure the unit has fully regulated output. True online UPS/power regenerator would be one of those type devices. Ferroresonant holds pretty tight too but they can be a bit noisy, tend to run warm/hot, and have poor efficiency especially at lower loading (relative to rating).
With most equipment nowadays having worldwide power supplies that can work just fine anywhere from 90-264V (100-240 +/- 10% which is the standard tolerance), voltage regulation is far less important today than it was years ago. Power supplies are also far more tolerant of dirty power than they were years ago which is why pure sine is not all that important, even in enterprise situations. The servers can take it Keeping power on long enough for a graceful shutdown is what matters.
I don't use anything like that for my computers, et al. I've only messed with power conditioning for audio equipment. In that arena many, if not most, still abhor anything switching; power supplies, amplifiers, etc. Myself, I'm not 100% sold on switching amps just yet although I have a couple and they do OK. Switching power supplies I don't mind too much if they're done well. I have about a dozen QSC and Crown pro audio type amps with SMPS and they work well.
I mess around with old tube amps some and they can run too "hot" on modern line voltage of 120+. Some I've reworked to tolerate today's line, others I run on bucking transformers that drop our line voltage from ~122-123, down to ~115V. If those amps had been designed around center operating points they'd probably be fine on today's line. But, quite a few of them were designed to run at the high end of spec and even beyond. Tubes back then could take it fairly well. Many of todays tubes can't take that stress. So, you either have to cut back the line with bucking, which is pretty easy and reasonably cheap. Or, tweak the design to drop the plate voltages and tweak the bias, or buy vintage tubes which can run $$$$$ for good ones.
Apology for the OT...
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J Sigmo
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Another advantage of power supplies that accept a wide range of input voltages is tolerance for surges.
I like that I can install a 150V MOV across the line, downstream from a fuse, and know that the equipment is well protected, yet I won't have nuisance trips of that fuse.
They also tolerate it when you forget to check the line voltage and find that something like a milling machine is using 240 as its internal "control voltage". (Of course I've never done that!
I have found that I've needed true sine wave UPSs more now than before, though because many new PC power supplies that have automatic power factor correction require a sine wave input. The older switchers really didn't care about the stepped waveform, in fact, they may have worked better with it!
And yes, for audiophile purposes, switching supplies and noisy line voltage is a concern.