What is PowerScope

[yashrk]

One of mine friend scored some test equipment called "881a PowerScope by McVan Instrument" , I want to know weather its an oscilloscope or something else. If it is something else then for what it is used ?

[johnwa]

Hi,

These are oscilloscopes specifically designed for working on high voltage, high power/three phase systems.  One model had four fully isolated and floating channels, and I think they are double insulated as well. I don't think the bandwidth is much to write home about, but it would be OK for low frequency work at least.

[yashrk]

So I can use it like a normal oscilloscope right ? can you suggest me some probes for it ?

[johnwa]

Yes, you should be able to. I am not entirely sure about that model, but I think the one I remember just used banana plug sockets. You can make up some leads out of coax cable, with banana plugs at one end, and crocodile clips or whatever at the other end. This should be OK, say, for below 1MHz. You might want to check the input impedance, as it is possible it may be something non-standard.

[GK]

The 881a was originally made down here by BWD Electronics, which was apparently bought out by McVan. BWD history:

http://en.wikipedia.org/wiki/User:Mosfet_RJF/BWD_Electronics

Lots of pics of it here:

http://www.iowa-industrial.com/Tristate-Area-/Metalworking-and-Production-/Numberically-Controlled-Equipmnent-/Bwd-881A-powerscope-ii-tested.cfm


From memory the only thing special about this scope was the vertical channel inputs, which were differential and designed/insulated to be safely connected to the mains. An Electricians scope 

[miguelvp]

Wow, 200V to 20 mV per division!
1 second to less than 1us  time division.

not sure what the min time is -5 is that half 1us? and then a -2, so It might do 4MHz BW?

[yashrk]

@miguelvp I didn't got what you want to say

Is it good or bad ?

[miguelvp]

Actually made a typo, I meant from 200V to 20 uV per division!

and it means that I'm impressed, never seen a scope that can do 200V per division directly. I mean we can get high voltage probes sure, but this can handle it inside it.

As for good or bad, you can't use this for fast signals over 4MHz, but for electricity, power supply stuff and analog audio it should be just fine.

For electronics you can use it as well, I2C for example is 400KHz so it will work with that too, so it will with RS-232 and many other things in electronics.

So what I meant was surprised by the specs, as in bad or good, it has its place. Someone that works on old pinball machines would love to have a scope like that I bet.

[yashrk]

@miguelvp thanx

[yashrk]

This scope is a pain in the a##, friends do you know where I could get manual for this oscilloscope (Bwd 881A powerscope ii).
Please I need it to understand all its functions.

[miguelvp]

Only hit I get for the datasheet (not the manual) is:

http://www.prime-electronics.com.au/datasheets/data/BWD/881A%20Powerscope.pdf

But they have removed it, there was another site that also had it and removed later on as well.

Only manuals from that manufacturer that I can find is:

http://bama.edebris.com/manuals/bwd

But nothing to do with the PowerScope, those are they previous regular scopes.

BWD Electronics was purchased by McVan Instruments, which is now part of the Observator B.V. group of the Netherlands.

One thing that can help is to post a picture of the full front/back and sides (if any connectors are on the sides) and people could tell you what is what.

[yashrk]

Sure will share its photos also

[RJFreeman]

Sorry for the late arrival but I have played with and own a BWD 881, although to be honest it is a year or two since I fired it up.

off teh top of my head it can be driven as a normal oscilloscope, only with differential inputs on two modified BNC type connectors.
to use regular CRO probes I purchased male BNC to female BNC adaptors off Ebay and used a hacksaw to cut off the bayonet latching ring on the male connector - these will then push onto/into the socket on the Powerscope.

As I say it has been a while, but if you have any questions I could probably dust off the powerscope on the weekend to re-familiarise myself with it. Especially since my TDS210 is currently waiting a new BNC connector ( don't ask) so I need to pull another scope out anyway.....

OTOH it has been several months since the OP, so maybe no one is concerned any more anyway 

[siddhant9850]

finally got it working............yeah

[RJFreeman]

Nice to see Siddhant.
if you wish to use regular CRO probes (although they won't be rated for 3KV etc) then Ebay item number 201094482511 can be modified by cutting off the bayonet shroud/catch on the male connector.

Of course while this would mean you can use the Powerscope as a regular CRO (although with differential inputs) it would not have the safety features of the correct probes for the powerscope....

eBay item number: 181353324297 is a probe for a power-scope but at $60 + shipping (not sure where you are) you would have to have decided you need it, but if you keep an eye on Ebay the probes do turn up from time to time.

Out of vague curiosity what was wrong with it?

[IconicPCB]

I worked at BWD when the concept of the powerscope was developed.

The scope initally had four high voltage lower bandwidth capability but it also has ( had) from memory either a 30 MHz or a 40MHz single channel of conventional capability.

The project was driven by John Beasley ( the B in BWD).

Along with the power electronics capability it had a digital PHASE METER.

BWD was bought out by a bunch of accountants who then did what accountants do and in the it was purchased by the production manager anda few other management personel.

The name McVan comes from their respective names ( a McPherson and something else which now eludes me ).

In the end McVan traded i n BWD, Syncotron and Austenna memorabilia.  McVan is still (?) alive in Melbourne

[yashrk]

It was around 30-40 USD, it needed some fix which cost us 2-3 dollars.

YashRK

[yashrk]

@iconicPCB McVan is still there actually I contacted them for repair manual but all they got was it's official user guide.

[RJFreeman]

I will have to have a scrounge through my Service manual/Data filing cabinet I think I do have a few scraps of schematic for the 881 Powerscope somewhere, pretty sure I had some schematics when I fixed mine (turned out a 12V regulator was faulty) but I would have to move a Burroughs L6000 first....

the earlier Powerscope (was it the 880?  - I did say 880 on Wikipedia, but then I also see that I mention an 882, which I don't think exists so not sure I can believe myself....) did have limited bandwidth on the higher voltage channels IRC but the 881A or Powerscope mkII goes to either 20Mhz or 30Mhz on the main channels depending on the range you select.

BTW for anyone interested I did start writing up a Wikipedia page on BWD - feel free to add or correct:
http://en.wikipedia.org/wiki/User:Mosfet_RJF/BWD_Electronics

[RJFreeman]

OK I have scanned the bits that I have, I fear they are incomplete and are copies of copies (and probably copies of copies of copies), but they are the best I have unfortunately.

The schematics look like they have been shrunk from A3 to A4 and then blown up to A3 again at some point in the past but hopefully you can mostly make out what is going on....

The largest file size this forum can handle is 1M and these are 2M each, Ebaman seems to be suffering a dummy spit at the moment (or is being stuffed by a firewall here at work) and likewise while BAMA says it is open for uploads I cannot get an FTP connection working so for the time being I have dumped these on Dropbox for the moment until I get home and try uploading from there.....

https://www.dropbox.com/s/2v0d3rdbdhotysa/BWD%20881%20part%201.pdf?dl=0

https://www.dropbox.com/s/8cs3eanyw5qierh/BWD%20881%20part%202%20schematics.pdf?dl=0

[RJFreeman]

... and now Ebaman is back I have uploaded them there also :

http://www.ebaman.com/index.php/remository/ELECTRONICS/Test-Equipment/BWD/

[IconicPCB]

I have manuals for BWD509B  and BWD830 scope.
My 830 was built form scrap pieces, junk bin etc.
Hand adjusted for 42MHz bandwidth. A tad above the spec.

[RJFreeman]

I have manuals for BWD509B  and BWD830 scope.

Ah yes, the at one time seemingly ubiquitous 509, I think I might have one somewhere along with a couple of spare CRTes. If it is the one I am thinking of it had hybrid Solid state and valve circuitry.
The 830 I am less familiar with, but I have (or did I give it away?) a 539 somewhere and a 521 packed away, but my favourite is the BWD 845, although maybe it just appeals to the Luddite within, to have/use an Analogue storage 'scope....

[IconicPCB]

The 845....

I seem to recall there was a contract from RAN to supply some scopes.. Beasley was very busy working up a new scope design for the contract..
I think it was an 84x something.

The prototypes were made and sent to GAF ( Government Aircraft factory,a place which lives on in memory )to be non destructively,  it was hoped, tested on the vibrating platform.

The scope survived and was delivered to RAN. It ofcourse could not compete with the Tektronix of the day but it was Australian made.

One of engineers at BWD was ex GAF.

[RJFreeman]

The scope survived and was delivered to RAN. It of course could not compete with the Tektronix of the day but it was Australian made.

Yes the Tektronix 466 was 100Mhz but the beauty of the BWD 845 even today is no odd ball custom IC's inside, and mostly all bog-standard parts (although the CRT would be un-obtainium today) for a trade off of only going to 30Mhz.
But sure you can see why BWD may have struggled to compete without the ability to tap the same level of resources/custom IC fab that Tektronix had available and then when cheaper kit from SE Asia started flooding in....