Recommend a Modest Scope

[PCBONEZ]

Re: Recommend a Modest Scope

Yes I made sketch. With MS Paint~~~
One of these days I need to find a real drawing program.

[Gianni]

Re: Recommend a Modest Scope

@ KeriJane: Yes... but I could be wrong because my colleague was in charge to buy the new equipment and IIRC he told me that price. We have two of them, one is a basic model and cost less than mine.
My LT344 contains an optional module for power line measurements and device power analysis. At bottom of this post you can see 2 images taken during power line test on a PSU.

"The more you learn, the less you know!" I think everybody must remember this phrase

@ i4004: I work in a small company, we are about 400 employees. We design e produce PS/Inverter/battery charger mainly for industrial application.
I work as a "jolly", when they need help in production I go there... when they need help in R&D I go there....when there are some returns from customer I do repair...
My work would be in R&D to realize prototypes and to debug them (only PSU not inverter/battery charger), I'm not an engineer, but in the last years the work has decrease so when I have nothing to do in R&D, my boss send me to work in other departments.

Ciao
Gianni

[i4004]

Re: Recommend a Modest Scope

Yes I made sketch. With MS Paint~~~
One of these days I need to find a real drawing program.

oh, paint is good.
do you want xp version(that also works on 2k) so you can save as .png?
for such graphics it looks better than jpeg and files are smaller.

gianni: thanks

[KeriJane]

Re: Recommend a Modest Scope

Yes I made sketch. With MS Paint~~~
One of these days I need to find a real drawing program.

Why not try OpenOffice DRAW? It's free and does all kinds of neat stuff.
It's got versions for Windows, Mac, Linux and practically any other OS.


Have Fun,
Keri

PS. How does MS Office stay in business with OpenOffice out there?

[KeriJane]

Re: Recommend a Modest Scope

Yay!

The OWON scope came in today!

This is a great eBay seller.... They got it to me in 4 business days with the free shipping option. It was brand new, in box and well packaged. It is exactly as advertised.

The contents: Scope, Power cord, USB cable, 2 1x-10x probes with detachable spring clip ends, a vinyl pouch containing the manual and a software CD.

The scope has a blank plate for installation of an optional battery pack. (also available from the eBay seller) Cool! It can run on battery power? for up to 5 hours they say. I'll have to get one.

Anyhow, the scope starts right up, the probes seem nice, the controls work well and I got the probes compensated in no time.

The screen has nice lighting and good contrast but a poor viewing angle.

Now on to a tired Antec Truepower that fried a hard drive and motherboard.... The PSU, board and CPU have been upgraded leaving me with the broken old ones which still kinda work. The PSU has new caps in it. Now I just gotta figure out what I'm seeing here.
It looks like ripple on the 12v and not as much on the 5v. The time base can go quite fast, to the point where the ripple is well spread out at 5.0ns/div. Interestingly, the ripple subsided a great deal AFTER the CD drive spun down and the PSU warmed up... it appears to be a bit over 50mv and about 200mv with the drive active (measured on a spare drive connector) That little ground wire seems essential as the signal goes absolutely NUTS without it.

Darn! I got Mac OS and the CD is Windows! That means I gotta go do Boot Camp and get into XP to do screenshots. Well, that'll be another day. Time for a hot bath right now. Maybe the Mac Pro needs a good scoping?

Conclusion: OMG! I love it! This modest little Chinese scope is about a Gazillion times better than anything I've used yet. It totally puts that TOY I use at work to shame. It's the first Digital Storage Scope I've used that actually seems somewhat responsive and reasonably close to real time.
Real Buttons and Knobs instead of icky plastic touchpad/ membrane switches! And $300 instead of $3000! Maybe I'd better not tell my manager that part

Have Fun,
Keri

PS. Oh! It's an OWON PDS5022S

[zandrax]

Re: Recommend a Modest Scope

@ Keri: not a photo? I'd be glad to see this wonder

Zandrax

[KeriJane]

Re: Recommend a Modest Scope

Hi Zandrax!

OK... here's some pix off of OWON's website.

Here's the page for this series scopes:
http://www.owon.com.cn/eng/pdsSeries.asp

Further scoping around stuff is underway.

Have Fun,
Keri

PS. Ahhhh! my nose looks all SUNBURNT! Not Fair!

[i4004]

Re: Recommend a Modest Scope

keri, i dunno if you're the wonder he talks about...hehe...
though, you look ok too, and i would rather see more of you than more of the scope.
<wink>

[Wizard]

Re: Recommend a Modest Scope

Ripping getting quiet with heat = sick capacitors, keep replacing all till you get a quiet small ripples.

Cheers, Wizard

[zandrax]

Re: Recommend a Modest Scope

@ Keri: the pictures on the Owon site seemed fake to me, so I asked you some photos of the scope just to be sure. I could and should have explained me better, thanks anyway.


Its appeareance seems really rubbery and I thought it to be a 3D rendering: judging from this photo, I was wrong

BTW, your nose seems normal to me: the "sunburn" effect is due to your monitor's backlight, next time switch on a lamp before shooting. Or, even better, take the photo outside home

@ i4004: the "wonder" I named is the oscilloscope because Keri stated it's above all her working pro gear while being even cheaper; "very good performance/price ratio" or "best bang for the buck" aren't as effective as "wonder". I agree the third picture shows another wonder as well, so be kind and do not scare this one

Zandrax

[KeriJane]

Re: Recommend a Modest Scope

Hi Zandrax!

OK, here's some real pix of my modest OWON scope. If I can figure out how to extract the saved waveforms I'll post those next.

The pix I posted from the OWON site are accurate. That's exactly the box it came in and the scope is a fair representation.

The screen itself is probably the weakest point of this scope but it's hard to argue with the price. The viewing angle is very narrow both vertically and horizontally and the contrast changes with temperature. The small black rectangle below the screen to the right of the nameplate is the contrast adjust thumbwheel.

There are handy little fold-out feet at the front of the unit that help a bit, but this scope really needs to be near eye level. The site mentions two screens, the cheap 256-color 'STN" one and a better "TFT" one. Mine being the least expensive model has the lower quality screen.

Have Fun,
Keri

PS. My favorite trick at work: Setting the Menu language to "Chinese" instead of "English" (Engrish?) Two simple button presses set it back to English.
PPS. I'm disappointed in my fellow technicians: Only a couple show any interest at all in learning the basics of a "Real" scope with a multitude of adjustments and options instead of the simplified handheld company supplied unit. Worse, only a few even know how to use THAT toy.

[KeriJane]

Re: Recommend a Modest Scope

A little further thought on Scope design.... My co-worker Lora pointed out that this scope is strikingly similar to the Heart Rate Monitors that her husband uses as a Paramedic! For sure they cost a whole bunch more that an OWON.

Our purpose-specific scope at work has a bare minimum of adjustments all set by membrane switches and menus, prints on wide receipt paper like the medical people use and has an odd poorly-shielded probe connection that looks exactly like an Ethernet cable.

All of these "scopes" built for specific uses and apparently designed for use by simpletons have very poor performance capabilities and extremely high prices.
Even our relatively "inexpensive" $3000 "Scope" costs more than a mid-level Tektronix that could easily outperform it by a huge factor.

Maybe this is a good business plan? Build an inferior scope with dumbed-down controls or just remove most of the switches and knobs from a lowest possible grade existing one, give it some specialized probes, maybe a beeper set to warn the nurses and jack the price way, way up?

Have Fun,
Keri
PS. I'm thinking about becoming a supplier to the Air Force or maybe NASA.... How's this:
"Manually Controlled Kinetic Energy Transfer Module - $150,000" (Hammer)
"Universal Panel Retention Units: $7,500/dozen" (Nails)

[PCBONEZ]

Re: Recommend a Modest Scope

Medical grade equipment has to use all parts (right down to caps and resistors) that are certified for use in life support equipment. The situation is similar to Nuclear grade equipment I used to work with.
Acquiring all those certifications drives the cost up really fast.
-
I remember comparing a "NUC Grade" Neoprene O-ring to the same thing without the certification papers. NUC Grade $1.53. Standard $0.15. Was the same manufacturer and same material. It's just that one came with a piece of paper showing it was tested for compliance to whatever standards and the other didn't.

Of course milking the system does play a big part in driving the cost up too but some of it is legit.

.

[PCBONEZ]

Re: Recommend a Modest Scope

I remember when the Air Force took some flack over a $3000 coffee pot in the cockpit of one of their cargo planes. - There was some specification/requirement that everything in the cockpit had to be able to handle 3G's and still work so the contractor built a coffee pot to handle 3G's.


.
Once I needed some .05" allen wrenches to work on the mechanicals in a particular meter assembly we worked on (adjusted) twice a year. (We had 36 of those.)
I ordered 4 wrenches at 11 cents each. Supply sent me 4 boxes of 100 wrenches by mistake. They refused to take the surplus back into the system because the total cost of $44 was less than $50. It seems the cost of doing the paperwork to return something to the supply system is estimated to be $50 so if what you want to return is <$50 they won't take it back. - So I got 400 allen wrenches for 11 cents and the system wrote off 396 wrenches as 'lost'.

.

[i4004]

Re: Recommend a Modest Scope

>Maybe this is a good business plan? Build an inferior scope with dumbed-down controls or just remove most of the switches and knobs from a lowest possible grade existing one, give it some specialized probes, maybe a beeper set to warn the nurses and jack the price way, way up?

not if people's lives depend on it....

[zandrax]

Re: Recommend a Modest Scope

@ Keri: thanks for photos.
STN (more likely CSTN, Color STN) is a passive matrix LCD technology which was used in notebooks up to late '90s: quality is inferior to TN screens (longer redraw time, lower view angle) but it's cheaper and this allows to keep prices low.
Don't be afraid of nobody wanting to learn how to use a scope: if you're the one with the knowledge, you'll be unvaluable for your job

PCBONEZ speech makes sense to me: medical equipment are certified and this reflects on price; they should be advanced enough for the job, more complexity is dangerous in lifesaving gear.
Another examples are archive or medical grade CDs: they cost 8 times a normal disc because they're certified to last 100 years and should use better materials (gold reflective layer instead of alu alloy, cyanine or premium phtalocyanine): raw materials take account only for a fraction of the price, smaller production and certifications' costs for another fraction, bigger profit for the difference.
[Indent: IMHO a 100 years lifespan isn't that useful if you can't be sure cd players will be produced in future: better look for more standard equipment with a 10-15 years lifespan and after that all data will be transfered to another media; anyway people buy them ...]

Zandrax

[KeriJane]

Re: Recommend a Modest Scope

Hello.

Yay! I finally got the time to Boot Camp Windows, install the OWON utility, plug the scope in and look at some screenshots.

The utility is very simple to install and apparently runs cleanly with no apparent background stuff goobering up Windows.

The user interface is simple and straightforward. It gives two options for communicating with the scope, the first continuously refreshes what is currently being displayed on the scope and the second captures the moment and saves it to a .bin file.

An option is given to print directly from the app or to save the screen shot as a .bmp file.

The saved screenshots apparently must be brought up on the scope's display before they can be sent to the PC.

So here's my first two saved patterns / waveforms?
The first was taken at the input of a noisy coil choke on my LCD TV set.
The second was taken at the output of the coil choke.

The particular circuit relating to this coil is marked: 5.3V
The first was set at 5V per division.
The second was set at 100mv per division.

I've since put an updated power supply board with a significantly different circuit design which has silenced the coil whine.

Have Fun,
Keri

PS. I don't miss Windows AT ALL! ❤Leopard❤

[Gianni]

Re: Recommend a Modest Scope

Welcome on scope world!!

My Tek DS210 had an additional module to connect it to PC or printer, I sold the interface 2 years ago to a friend because I barely use scope at home and he needed the interface.

IIRC the software to manage the picture was easy to use but very poor with function and it worked only on Win98.
The last picture I made with my Tek was taken directly trough RS232 and I didn't have the SW because I was on Win2000. The pictures were in B/W and they were not very good.

Can you save pictures with parameters? I mean T scale, V scale... etc?
I think you can also change background color otherwise if you print your picture you will need liters of black ink.

Be careful if you have to analyze live side, you need a safety transformer to separate the scope ground/earth from the EUT.
Take care also for probe, usually they can support 400~600Vpk, if you need to check signal greater than 600Vpk (flyback Mosfet, CRT EHT transformer/Transistor) you need and high voltage probe: I have bought (long time ago) a probe which is 100:1 and it is rated 2KVpk.

Ciao
Gianni

[i4004]

Re: Recommend a Modest Scope

just came across this on the web



hehe..liliput...

[zandrax]

Re: Recommend a Modest Scope

@ Keri: well done.

@ i4004: read Lilliput as Junior technology, a name for a simple products with few but essential functions. IMHO better than a gazillion features you will rarely (if ever) use for 20x its price
It works, it's cheap and seems robust enough; the only defect: doesn't make coffee

Zandrax