Products > Test Equipment

SDS1104X-E, backup power supply

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JeremyC:

--- Quote from: Linwood on February 15, 2023, 04:40:28 am ---
--- Quote from: JeremyC on February 15, 2023, 04:24:37 am ---You need double-conversion UPS, but they are expensive. I doubt you will be able to find 1000 VA below $700.
--- End quote ---

Well, I don't "need" one, really, which is why I have some cheap ones running my network gear so (for example) VoIP phone works when the power is out, at least for a while.  I might like to have one, but it does not seem worth it.

Unless you are saying I need one for the scope when power is out, but the suggestion to use the EV car seemed viable.

--- End quote ---


--- Quote ---I have a standby generator for the house and am curious how clean its output is.  Now when I run it, I mostly turn off expensive electronic stuff just in case.

--- End quote ---

It was only suggestion how to condition the electricity delivered from your generator.
Sorry for the understatement.

Linwood:

--- Quote ---
--- Quote ---I have a standby generator for the house and am curious how clean its output is.  Now when I run it, I mostly turn off expensive electronic stuff just in case.

--- End quote ---

It was only suggestion how to condition the electricity delivered from your generator.
Sorry for the understatement.

--- End quote ---

Ah... got the context now... yes.

I was thinking in terms of brief power outages, which is where the UPS' now come into play (but not the generator as it is a bit of an ordeal to get it set up, outside and running -- it's not stationary, but sort-of portable).  Utility power is clean enough a double-conversion is not needed.

But for the generator, if I look and it's really ugly power, you are of course correct, cleaning it up would require double conversion.

I'm hoping I will find a nice more or less smooth sine wave since it has a fairly large generator body, but haven't looked.

Sorry for the first reply, it now makes all kind of sense.

TomKatt:

--- Quote from: Linwood on February 15, 2023, 12:47:07 pm ---I'm hoping I will find a nice more or less smooth sine wave since it has a fairly large generator body, but haven't looked.

--- End quote ---
If you're talking about one of those 'utility' generators that sits in a metal tube frame with wheels, don't expect much.  They're typically pretty crappy.  I had a 'decent quality' Generac branded version and my furnace fan motor made some horrible sounds when I ran it off the generator.  I eventually got a sinewave generator for the furnace fan.

Those kind of units also tend to have quite a frequency variance in them beyond the spurious noise.

robert.rozee:

--- Quote from: TomKatt on February 14, 2023, 04:17:22 pm ---[...]
I'm thinking more along the lines of a "replacement" psu that runs off 12v and creates the +15v, +6.5v and -9.5v rails used by the SDS1104X-E...  I can't imagine any of those require significant current.

--- End quote ---

i've been working on replacing the toasted PSU in a friend's Hantek DSO5072P, where the main supply rails draw 2A @ +5v, 400mA @ +14v, and 200mA @ -8v. i would expect the Siglent to be similar, with the highest current draw being from your +6.5v rail. in the case of the Hantek, i had considered converting it to battery operation, but in the end have just modified a salvaged PSU from an old DVD player instead.

an interesting idea: there will be three schottky diodes in the Siglent's PSU, one for each of the three rails. take a wire from each (on the side away from the transformer) along with ground to a 4-pin connector located somewhere on the back of the scope. you can now feed regulated power into here, making use of the filter capacitors and chokes already in the PSU.

a small external box can then house switching converts: buck input down to +6.5v, then boost this back up to +/-15v. finally use a 3-terminal negative regulator to bring the -15v back to -9.5v. size the buck converter large, to handle 5A or thereabouts. this gives you the ability to run the scope on anything from 8v up to 27v. if keen, add an under-voltage lockout.


cheers,
rob   :-)

Linwood:

--- Quote from: TomKatt on February 15, 2023, 12:57:41 pm ---
--- Quote from: Linwood on February 15, 2023, 12:47:07 pm ---I'm hoping I will find a nice more or less smooth sine wave since it has a fairly large generator body, but haven't looked.

--- End quote ---
If you're talking about one of those 'utility' generators that sits in a metal tube frame with wheels, don't expect much.  They're typically pretty crappy.  I had a 'decent quality' Generac branded version and my furnace fan motor made some horrible sounds when I ran it off the generator.  I eventually got a sinewave generator for the furnace fan.

Those kind of units also tend to have quite a frequency variance in them beyond the spurious noise.

--- End quote ---

It is one of those.

I have put a frequency counter on it (my DVM has one) and it's pretty steady even when adding and shedding load, as is the voltage.  I don't think I saw more than +/- 1 hz (though it has been a long time) and maybe +/- 5v rms.

It's a Northstar  (Northern Hydraulic now Northern Tools) 13k surge / 10k continuous from somewhere around 2017, nice Honda engine, but few details on what's inside the generator portion, just "rotor" and such.

To date it has been through three hurricanes here, and served its purpose -- it prevented me from loosing power.  Even Ian, which was almost a direct hit here and wiped out whole communities on all sides did not take our power (we were without water for about 2-3 weeks).  Like taking an umbrella out prevents rain.

So I consider it well worth the money -- without being prepared I would have lost power and maybe  still not have it back.    :phew:

But how well it works... Maybe in a day or two will drag it out and get set up to run it.  Having fun now looking at noise induced by PWM power to telescope dew heaters with various power supplies. I have no idea what to make of all the info I see, but it's drawing really cool images.   Fun to look at.  :popcorn:

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