So I bought an oscilloscope...

[Red Squirrel]

Thought I'd share various UPS outputs from around the house.


Ultra 1000AP:


(switching to UPS power)




APC Back UPS ES 750:







Tripp Lite APS 750 inverter-charger: (I was expecting better, this is a slightly higher end unit)




(returning to AC power... good feature of this UPS is that it waits several seconds to ensure AC is stable)


Closer look at the wave



APC Back UPS XS1000:






Note: This is not exactly a scientific comparison, just random tests. To make true comparisons I'd need to pull the power at specific times during the AC cycle to see the different ways they react. They also have different loads. The APS 750 has the highest.

 

[silicon]

i think you will find that consumer grade ups units are similar in their operation. To continue power the inverter makes a square wave from the DC stored in the batteries. I see that there is a lot of overshoot when it switches to create AC current. The computer power supply should clean this up.

 

[Blain]

So I bought an oscilloscope...

Hehe... Perks of being single... :biggrin:

Your house must be filled with gadgets.

 

[Jeff7]

If you don't know already, do be careful when probing around line voltage, specifically with regard to what that ground lead attaches to.

How to not blow up your oscilloscope.




I've got a sinewave output UPS at home. It's a fairly big one, sort of a reserve backup for when the power goes out. I've also got a sinewave inverter in the car.
I just got sinewave outputters so I wouldn't really have to think about what was connecting. Yes, regulated power supplies don't care, but I can also connect small motors or anything else I might need when there's no power.

I'll have to scope their outputs sometime to see what they're actually generating.
The UPS is a TrippLite. The inverter is an Amazon-special.

 

[Red Squirrel]

If you don't know already, do be careful when probing around line voltage, specifically with regard to what that ground lead attaches to.

How to not blow up your oscilloscope.




I've got a sinewave output UPS at home. It's a fairly big one, sort of a reserve backup for when the power goes out. I've also got a sinewave inverter in the car.
I just got sinewave outputters so I wouldn't really have to think about what was connecting. Yes, regulated power supplies don't care, but I can also connect small motors or anything else I might need when there's no power.

I'll have to scope their outputs sometime to see what they're actually generating.
The UPS is a TrippLite. The inverter is an Amazon-special.

Yep watched that video. I was using an AC power adapter to lower the voltage and also to act as isolation. I'm not sure if I feel comfortable putting the scope right into the AC socket yet, it's too new and shiny to blow up. At 10x it's good for like 300v though so I'd most likely be fine. For a more scientific test I'd probably want to probe directly as the AC adapter could potentially change the wave form a bit.

Your house must be filled with gadgets.

Yeah too many. My kitchen counter kinda doubles as a lab or place to store tools to put away later (very later) sometimes lol. Though I try to keep it clear. My mom gives me heck when she visits. :biggrin:

 

[William Gaatjes]

That is a nice scope. How many channels ? USB too, i guess.

If you want to measure high voltages, have a look at high voltage probes (1:100) for your oscilloscope.

 

[MongGrel]

I wouldn't know what to do with one

 

[imagoon]

That APC is a decent modified sine wave. The triplite is a mess though. Look for good stepped sine wave or true sign wave unit if you want to get longer life out of the batteries (less waste as heat.)

Have you hooked up to that beast in your basement yet?

 

[Red Squirrel]

That APC is a decent modified sine wave. The triplite is a mess though. Look for good stepped sine wave or true sign wave unit if you want to get longer life out of the batteries (less waste as heat.)

Have you hooked up to that beast in your basement yet?

The beast in the basement IS the tripp lite, oddly enough. I knew it was not pure sine but figured it would be a tad nicer than that. I want to replace it with a pure sine inverter though, and rectifier bank, and move to a -48v system. Probably at least a few years before I do that though. I told myself I have to stop spending so much on my server setup till I can find a way to make it make me money.

The oscilloscope is a Siglent:

http://www.amazon.ca/dp/B00GQNNHJG/r...ywords=siglent

With that sale I could not pass it up. Wanted to eventually buy one but was going to wait till I get deeper into electronics.

 

[Jeff7]

The beast in the basement IS the tripp lite, oddly enough. I knew it was not pure sine but figured it would be a tad nicer than that. I want to replace it with a pure sine inverter though, and rectifier bank, and move to a -48v system. Probably at least a few years before I do that though. I told myself I have to stop spending so much on my server setup till I can find a way to make it make me money.

The oscilloscope is a Siglent:

http://www.amazon.ca/dp/B00GQNNHJG/r...ywords=siglent

With that sale I could not pass it up. Wanted to eventually buy one but was going to wait till I get deeper into electronics.

Nice.

Siglent SDS1052DL here. I just don't feel much need for (signaling) speed.

 

[Red Squirrel]

I almost bought the 50mhz one actually, but figured for a little bit more I can go to the 70. There is also supposedly a hack to make it 100, not that I really need that yet.

I still need to watch tutorials and stuff to learn more how to use it. I don't know what half of these buttons actually do.

 

[Z15CAM]

I was assigned an Oscilloscope back in my College Years that would not hold a calibration so I learned to fabricate figures in my Digital Lab Reports. In my conclusions blamed my percentage error as a function of the apparatus I used. Of course I held most results with in 5 to 25% error or report a perfect result and sometimes I would throw in a report at over 200% error concluding that the Oscilloscope was a piece of crap . The Faculty never admitted that the Oscilloscope was faulty or replace it - LOL

 

[Red Squirrel]

I was assigned an Oscilloscope back in my College Years that would not hold a calibration so I learned to fabricate figures in my Digital Lab Reports. In my conclusions blamed my percentage error as a function of the apparatus I used. Of course I held most results with in 5 to 25% error or report a perfect result and sometimes I would throw in a report at over 200% error concluding that the Oscilloscope was a piece of crap . The Faculty never admitted that the Oscilloscope was faulty or replace it - LOL

Hahaha that is pretty funny.

 

[phasseshifter]

typically most peop`s that run cro`s for a day to day basis generally use a mains isolation transformer in conjunction with them..the earth or ground terminal on a cro is earthed to chassis earth and therefore grounded..newer cro`s may differ but in most of my time spent using them the earth was tied to ground.....on another point just because your using a mains isolation transformer does not mean you cannot be electrocuted..important fact to know... i cannot stress this fact enough....

 

[Red Squirrel]

What's a cro? Given the context I'm guessing it's another name for oscilloscope?

From what I read it's a bad idea to isolate it, I really don't know why though, there's not really anyone that explains why. Obviously if you isolate it you do not want to touch the chassis ground of the scope including the ground pin.

I have not played with mains stuff yet though, for my readings I used an isolated (no ground) AC wall wart. That may potentially alter the readings if I was testing for something specific though, as the transformer itself may have some capacitance or other effects.

Do scopes bond to the neutral or use strictly ground? I imagine easiest way to isolate would be to just not use the ground. I have a box I use for plugging power bars into a Christmas light timer (2 prong) which basically has a power cord with the ground pin cut off and has a GFCI outlet. That would probably work to isolate the scope assuming they don't do anything with the neutral.