Well, it's not where it used to sit next to the armature growler. I was going to post a pic of it. No idea where it might be.
You're using an inverter, you say?
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- #23
the good thing, though, is that every so often I find something in there that I did not remember I had but may need and it's like Christmas all over again....
T'is the season of jolly...!!
T'is the season of jolly...!!
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- #24
Back with an update of sorts: I'm even dumber than I thought when it comes to inverters...
In the OP I had looked into what garbage waveform comes out of cheap inverters.
What I had not thought about but just dawned on me is that there are inverters in other ubiquitous devices: UPSes!
Obviously, right? Well I didn't think about it. But yesterday I fixed up an older UPS (tweaked it to accept a big LFP battery) and then realized that of course if the mains go off, you go on battery but then are completely at the mercy of the waveform coming out of the UPS. Looked into it and sure enough the waveform out of that thing is terrible, with a THD of about 40%. Highly modified sine wave. I would say worse than the one in the OP pic. And yet it's designed to power computers and electronics... Yikes!
So, yea, the same warnings should apply to UPS devices as well. Now, thankfully, the new ones may be better sine waves, but something to watch out for when shopping, I think. I'm seriously considering scrapping my older UPSes now given all that.
In the OP I had looked into what garbage waveform comes out of cheap inverters.
What I had not thought about but just dawned on me is that there are inverters in other ubiquitous devices: UPSes!
Obviously, right? Well I didn't think about it. But yesterday I fixed up an older UPS (tweaked it to accept a big LFP battery) and then realized that of course if the mains go off, you go on battery but then are completely at the mercy of the waveform coming out of the UPS. Looked into it and sure enough the waveform out of that thing is terrible, with a THD of about 40%. Highly modified sine wave. I would say worse than the one in the OP pic. And yet it's designed to power computers and electronics... Yikes!
So, yea, the same warnings should apply to UPS devices as well. Now, thankfully, the new ones may be better sine waves, but something to watch out for when shopping, I think. I'm seriously considering scrapping my older UPSes now given all that.
On the Tear-drop & tiny trailers forum there is/was a guy who charged his trailer's battery with a 120VAC battery charger. Which was plugged into a pair of extension cords that were in turn plugged into an MSW inverter under the hood of his TR. Got him around the Voltage Drop over some distance charging problem even if it wasn't terribly elegant.
Which leads me to wonder, would passing that MSW thru a transformer (1:1 or otherwise) clean up the wave form any or would it just be GIGO?
Which leads me to wonder, would passing that MSW thru a transformer (1:1 or otherwise) clean up the wave form any or would it just be GIGO?
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- #26
For a regular transformer with plain coils, I would think the waveform would be identical in and out. Unless there are a bunch of caps or active control.
But what you are describing sounds odd. He goes into an extension cord with DC, connecting to an inverter then yet another AC to DC charger?
Either way, to reduce losses over long distance you want high voltage, not low. So he would be better off to have long 120V AC extension cords and then an AC to 12V DC charger I would think.
But what you are describing sounds odd. He goes into an extension cord with DC, connecting to an inverter then yet another AC to DC charger?
Either way, to reduce losses over long distance you want high voltage, not low. So he would be better off to have long 120V AC extension cords and then an AC to 12V DC charger I would think.
Bummer, oh well I thought that might be the case.
No, inverter under the hood, two extension cords (break at the rear bumper) to the 120VAC charger on the trailer, then into the trailer battery. He's roughly duplicated high voltage transmission lines to get 12VDC to charge the trailer battery.
It is odd by most points of view, but from purely a power transmission perspective it's perfectly logical.
No, inverter under the hood, two extension cords (break at the rear bumper) to the 120VAC charger on the trailer, then into the trailer battery. He's roughly duplicated high voltage transmission lines to get 12VDC to charge the trailer battery.
It is odd by most points of view, but from purely a power transmission perspective it's perfectly logical.
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- #28
I'm kinda bummed TBH that I thought I was doing the right thing by using a UPS to protect my computer from a sudden power interruption and yet I set it up to continue working all right but possibly getting fried by bad AC...
This kinda reinforces the disturbing (to me) notion that one should not keep electronics too long cuz the new stuff may be significantly better... I just hate obsolescence!
This kinda reinforces the disturbing (to me) notion that one should not keep electronics too long cuz the new stuff may be significantly better... I just hate obsolescence!
Build your own UPS using a LiFePO battery with a LiFePO-specific charger and a Xantrex PSW inverter?
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- #30
Yes, I did that before but that is not quite the same as a true UPS cuz you want software to shut down the computer softly when the battery gets too low. And my UPS also has surge protection, programmable slave outlets, variable sensitivities etc.
Big Cap for surge or are those more sophisticated than that?
Raspberry Pi or Arduino control then? Suddenly beyond my pay grade.
Raspberry Pi or Arduino control then? Suddenly beyond my pay grade.
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- #32
That would be beyond me too.
One thing that intrigues me is that some of the "solar etc" power stations you see so much out there now can function as a UPS of sorts. Some with a PSW inverter supposedly. And not much more expensive than small UPSes. But much more versatile. And some supposedly will do a transition in 10ms or so. But that still won't help with the soft shut down for the computer I imagine. Although of course if the battery is big enough, the computer would probably run long enough that you would be able to deal with it even if not present at first.
Of course, all of this is a moot point if you can do your work with a laptop, but sadly I can't.
added: I just saw that at least one of those power stations also has a USB port to allow for soft shut down of the computer and also has battery bypass and pure sine wave so looks like that one would work just fine as a UPS.
One thing that intrigues me is that some of the "solar etc" power stations you see so much out there now can function as a UPS of sorts. Some with a PSW inverter supposedly. And not much more expensive than small UPSes. But much more versatile. And some supposedly will do a transition in 10ms or so. But that still won't help with the soft shut down for the computer I imagine. Although of course if the battery is big enough, the computer would probably run long enough that you would be able to deal with it even if not present at first.
Of course, all of this is a moot point if you can do your work with a laptop, but sadly I can't.
added: I just saw that at least one of those power stations also has a USB port to allow for soft shut down of the computer and also has battery bypass and pure sine wave so looks like that one would work just fine as a UPS.
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I know nothing about the Raspberrys. My previous employer used Arduinos in their early production automation. Mostly for signals I/O to a PC, but there were a couple stations set-up stand alone. Given that the Arduino was originally conceived to be a teaching tool I'd think that most anyone with an interest could figure out how to get it to do what you want.
Arduino - Home - https://www.arduino.cc/
The rumor has been that the name "Arduino" comes from the name of the Spanish bar where it was first sketched out on a paper napkin. That tickles me!
Arduino - Home - https://www.arduino.cc/
The rumor has been that the name "Arduino" comes from the name of the Spanish bar where it was first sketched out on a paper napkin. That tickles me!
FrazzledHunter
SILVER Star
I've always had pure sine UPS's for my computers, network gear, monitors,WiFi, Verizon ONT and security system.
Security cameras run off POE so they're backed up too.
FrazzledHunter
SILVER Star
I love this idea. If you do this then there's no "switchover". I have a Goal Zero 1500X that I'll retire in favor of something newer and I'll have my computer and other sensitive gear plugged into that. That will mean continuous A/C power with the prospect of supplying power for a much longer period of time.
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- #36
^ I've done that and even had the battery being recharged with a solar panel, but there are a couple of issues with that approach -that may or may not be something you care about, of course- : First you are constantly losing energy because of the inefficiencies in the charger, inverter and battery and that will cost you; and Second -depending on the load and charging ability- the constant charging and discharging of the battery if any will reduce its life expectancy. Plus possibly that the waveform will not be as good as mains AC. Which is why real UPSes do AC passthrough and battery bypass, even some of the new LFP power stations. And you'll also have to be there to shut down the computer manually when the battery is discharged if the battery/power station does not support shutdown software.
But, yes, it works and is fun to see operate (I used the Victron software) and -if set up that way- to have your computer operate partially or even entirely on solar power.
But, yes, it works and is fun to see operate (I used the Victron software) and -if set up that way- to have your computer operate partially or even entirely on solar power.
FrazzledHunter
SILVER Star
Costs associated with inefficiencies or life expectancy of batteries are to me of no consequence when it comes to expensive electronics, IMHO. The assumption is that a large 1500Ah battery would provide many hours of backup. But what if it isn't enough? The assumption is that I'd be around to shut things down if necessary. But what if I can't be around? So, the lack of integrated shutdown software is a real issue. It's something I'll have to think about. It actually sounds like a product idea. Good catch.
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- #38
^ 1500 Ah? That's not large, that's gigantic! Are you aiming for a week of running on battery? My workstation with a monitor is using something like 100-150W average IIRC. I can usually last about a work day on a typical 13V 100Ah battery.
How does a UPS execute a soft shut-down? Software driven I'll guess, but how does the computer get the message? That is what I was proposing the Arduino or Raspberry Pi could do, assuming it can be figured out if not already known. (I'm sure the UPS mfg's know, but does anyone else?)
Assuming that you can't do so with the Victron software, you could likely set up something external (Arduino or Pi, again?) to only turn on the charger when the battery is at some fixed SoC. I'm sure that an Arduino or R-Pi could also be set it up to do an AC pass-thru and switch-over. A PLC could do it, too.
Assuming that you can't do so with the Victron software, you could likely set up something external (Arduino or Pi, again?) to only turn on the charger when the battery is at some fixed SoC. I'm sure that an Arduino or R-Pi could also be set it up to do an AC pass-thru and switch-over. A PLC could do it, too.
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- #40
the UPSes I am familiar with have a USB port to connect with the computer and proprietary software that you run on that computer that monitors the UPS via a USB cable and will do a soft shutdown when the UPS battery gets to be too low.
You could surely have Victron hardware control relays, but I don't know that their software can do a computer shut down. Not sure, it's been a while since I used my Victron management software.
You could surely have Victron hardware control relays, but I don't know that their software can do a computer shut down. Not sure, it's been a while since I used my Victron management software.