Test Equipment Anonymous (TEA) group therapy thread

[dl6lr]

Todays collection was the other 5245L with the time interval plugin. With rack mount ears but missing the feet.

As you can see it is freshly calibrated by -hp- only 20 years ago! It got a temporary place on my NFM.

Progress with the first 5245L: Replaced all neon bulbs. What a mess. All copper wires were corroded, most have them already were destroyed at one leg.

[mnementh]

On the TinkerDwagon's Bench today:   
   If I can't get the BMS to charge, I'll probably have to remove it and solder a JST/XH pigtail on the cell cluster so I can balance charge with the Reaktor.

Normally this kind of dickery with individual cells is a fool's errand; one is better off rebuilding the pack with known-good or new matched cells. But given the model, this pack is probably 3-5 years old; so it is possible I'll get lucky.

   Ugggh. BMS is totes being a whiny little bitch.     Refuses to start/turn on to charge, so balance charging the pack on the Reaktor. Safety fuse tests good, each voltage monitor leg tests the same resistance FWD/REV EXCEPT cell 1; it measures approx 630KΩ/10MΩ where the others measure ~5MΩ/10MΩ. This may or may not be a bad thing; cell 1 is where the BMS usually draws power for the supervisor chip.

It is entirely possible the pack sat unused long enough for this miniscule drain to have drawn cell 1 down to the point where the BMS shut down due to imbalance; only time will tell.

Well, time told... me to take a different approach. 

After an afternoon doing the deep-dive trying to reverse-engineer and researching these particular batteries online, mostly what I was able to find was that a) They're effing expensive. b) I am probably actually related to Billy Connelly. (depth-first searches, ehhh...?!) and 3) You can buy a Chinesium BMS board just for the thing for aboot $15; it's marketed to 18650 cell recyclers/pack rebuilders, but you have to wait for the slow boat from China.

   

Well I have perfboard, a Dremel and oodles of generic Chinesium BMS boards. 

This is a 20A module so probably a wee bit overkill, but it's the only 4S one I have on hand with the correct configuration. First, I float the metal contact pads off the original BMS with my cheap Chinesium Hot-Air Rework station and onto the perfboard PCB I've carved out with my Dremel. Easy-peasy. Next, I add the balance pigtail and some main power straps.

      

Once I have the balance pigtail connected everywhere, I can plug it into the BMS & attach the power straps to the pack. I usually do (-) then (+) on these generic BMS modules; if you do them in the wrong order often the BMS will go into safety shutdown and you have to desolder them all, short the pins on the BMS for a few minutes to fully discharge it, then resolder all  connections again. After that, time to stuff it all in the shell & screw it back together.




The Money Shot!

Here I've cleared the first hurdle; dropping the battery in the Roomba, it powers up and doesn't have a shit-fit conniption aboot non-OEM battery. A little pigtail of Cat5 strands snaked out the compartment lets me observe as I connect the Roomba to the charger base; hurdle 2 cleared as it starts a normal charge and doesn't bitch that the battery is too hot/too cold/not the right type/not genuine/not possessed of the magical rings of Lhasa or whatever incantations it needs to make its little Roomba brain happy.

And just to keep it TEA, here's my HP Thermal Monitoring Hydration Cylinder full of... Iced Tea. 

Charge rate is very slow, but the pack is already fully charged. So now time for some IRL testing.

Roomba seems happy to run on this pack; it's been going almost 2 hours now while I made dinner and this post. It is very thorough, and much quieter overall than the Scooba.

Big HELL YEAH : The Spot Clean mode works effing awesome; I set it after the front entry rug and it made short work of a good mess of crusty dirt chunks and tracked-in leaves. I can see this thing being a MVP come the change in seasons just for that.

That said... not a total win yet. One thing I've seen out in the wild is manufacturers using the THERMISTOR circuit as more than a thermistor; they will often use it to communicate information aboot the battery back to the host device, either via simple voltage level monitoring or digital information they will tell the host battery type, capacity, Ser#, temp, even number of charge/discharge cycles and more.

So still more real life testing to go... If the unit thinks this is the wrong type of battery (NiMH instead of Li-Ion) it may set a wrong low-voltage threshold, or even try to charge it via peak-detection rather than CC/CV as a Li-xx pack needs. I'm not worried aboot it damaging anything with the BMS module acting as traffic cop; but it may not charge automatically like it should (this thing is supposed to find its dock and auto-park itself to charge); it may stop too soon or take days or just not start a proper charge cycle at all.

But at least I've confirmed pretty well that the cells in the pack are still good. I think.

If it doesn't work, I've had fun tinkering; then the choice will be whether to buy the bespoke Roomba Chinesium BMS, or just get a cheap NiMH pack off Amazon.

mnem
 

[vk6zgo]

Ah Kwinana, just up the road from where our Larry is in Warnbro.
Is that where the WA gasometer used to be ?

We had one near downtown Auckland when I was a lad but of course now long gone for the valuable real estate it covered. 

Nah, it was in East Perth, adjacent to the old East Perth Power Station.

It was still around for quite a while after it went out of service----long gone, now, of course, with the "gentrification" (aaaarrrrgggghhhh!) of the area.

I don't think the old SEC in WA ever converted Kwinana LPG to "town gas", as, after the demise of steam trains, they were pretty much Collie's only customer for Coal.

[vk6zgo]

Cng is cow farts at 200 bar. LPG is liquified propane/butane . Vol o offered both version the energy density of cow farts is considerably higher than LPG

Ah OK thanks for the details, didn't know you could have different kind of gases in these cars. Here at the pumps we have LPG, so according to Google, a mix of butane and propane, mostly, as you said. So cow gas is more energetic then ? That's cool... I mean they all say how cow farts is tremendously more dangerous for the ozone layer than CO2 emissions... so let's make use of it to power cars rather letting it blow a hole in the ozone layer ! 

It's the usual media (over-)simplification with methane from cows - yes they always produce methane, yes methane is a more powerfull "greenhouse effect gas" than CO2 but a cow on a pasture feeding naturally has low emissions. A "high octane" milk cow that lives inside, gets fed much soy protein and other stuff to pump out 13000L milk a year - now that one has worrysome amounts of methane emission (and, TBH lives a shitty live IMHO). It does allow to fuel a biogas reactor from it's manure alone, that can be readily collected in such an environment - so it is exploited to the end, in a way...

Why imply CNG is a agricultural byproduct when it's not ! 
As CNG's last 2 letters implies it's a natural gas from the bowels of the earth and a byproduct of oil wells and in many cases targeted from natural gas fields then compressed to provide better density and therefore greater range when used for ICE fuel. In low pressure form it's domestic and industrial fuel used for all manner of generally heating requirements.

Here I register my offence in CNG being associated with agricultural emissions !   

OK I am lost now, was this CNG a joke of Saskia I didn't get, and it's just another name for the LPG/GPL stuff we have in France...

Sorry Saskia, I guess I was not 100% today.... 

CNG in Oz is stuff that comes out of the ground, is compressed, & used as fuel for industrial processes, home cooking, & electricity generators, as well as city buses.

Western Australia had the foresight to reserve a reasonable proportion of the CNG produced in the State for local use.
The other States "went ape" about the export earnings & sold most of theirs overseas, now being in the embarrassing position of having to "buy it bacK!"

Of course, CNG is a fossil fuel, & is not sustainable in the long term, but it is a lot more environmentally friendly than Coal, which quite a bit of East coast power generation relies upon.

The WA gas is from "deep wells" offshore, & doesn't use "fracking".

Surely CNG is sustainable, as long as there are people and animals about pooping and dumping rubbish in landfill sites and then covering them over with soil. Correct me if I'm wrong but CNG (cow farts etc) is just natural methane isn't it?

If you want to keep your cows pooping for several million years, ----yes!

CNG comes from the same source as petrol/gasoline------it is from ancient vegetation, dead dinosaurs, etc, which have been compressed naturally under natural rocks forming over many millennia.

It seems in some countries it can be made from cow poo, but that is not mainstream----nobody creates a massive export industry from processing cow poop!

[vk6zgo]

Hmm I've got a decision to make. I was contacted by a "head hunter" a while back. A proper one,

Like this?

[bitseeker]

Oops i did it again 

Keithley 230 prog. voltage source.. 
now figure out how to pay for dinner for the rest of the mounth... its not that long   

Very nice one! It even has its metallic decal on the tilting bail. Nice catch. I don't yet have a 230 (so far, my "brown" collection consists of 196, 220, 614, and 228A).

What's next on your list?

Thank you
Nice collection of brown !
was looking for a 220 or 224 .. but they are crazy priced, so no rush at all, waiting for a good deal.

Yes, the prices do get rather crazy on those as well as the 263. Just have to be patient...quite patient.

[med6753]

Mentioning the need to re-cap the Fluke 8060A got me wondering about my similar vintage 8021B. How many electrolytics, if any, does it have? So I opened it up and took a look. Two. Both up to the bottom right of the LCD. And verified this via the parts list. Both 22uf/16V. When I do the re-cap of the 8060A I'll do this guy too.

[bitseeker]

Metrix Wobuloscope back on the bench.

That's a nifty device. Have you posted about it before? If so, I missed it.

Yep I posted about it a month ago the day I unpacked it, as I usually do, here it is/was :

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3706627/?topicseen#msg3706627

Thanks for the link!

Now the center of my attention, it's its turn.

And you got the correct forms of "it's" and "its". You're doing far better than many native speakers.

Thanks !    I try to do well where I can... hoping people would then forgive all the mistakes I do without even realizing it .... it's about balance ! 

The natives also mix  to/too, your / you're ... I guess every language tends to mix things that sound the same.

Same problem here in France, only much worse / severe, it's a complete shit show over here.

A memory aide (for anyone who'll find it useful) for differentiating the "it's"/"its" forms is that "its" is possessive, like "his" and "hers", all of which do not have an apostrophe. Granted, one could misremember the female possessive pronoun as "her's", but surely the male possessive pronoun "hi's" does not look right.

[bitseeker]

Well since a number of you are always singing the praises and swooning over an 8060A I figured I'd join the club and see what all the fuss is about. Should be here early next week. It looks a little dirty but should clean up. Seller claims 100% functional.

Good to know the seller is still functional. Hopefully, the packing is as well. 

[bitseeker]

Hmm I've got a decision to make. I was contacted by a "head hunter" a while back. A proper one, they got non public contact info for me from someone.  I had a couple of online interviews which I was not too bothered about. Then I got a call tonight to say an offer is in the post...
Now I'll have to make my mind up.
(No I can't say what it is. The employment conditions of my job mean I can't talk about other than it's aerospace).
 

Congratulations!

"My job is so secret, even I don't know what I'm doing."
(seen on a t-shirt)

[tautech]

Mentioning the need to re-cap the Fluke 8060A got me wondering about my similar vintage 8021B. How many electrolytics, if any, does it have? So I opened it up and took a look. Two. Both up to the bottom right of the LCD. And verified this via the parts list. Both 22uf/16V. When I do the re-cap of the 8060A I'll do this guy too.

Everything you need to know about these old classics is here in a thread by their designer Dave R Taylor:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

[med6753]

Everything you need to know about these old classics is here in a thread by their designer Dave R Taylor:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

I am aware of that thread and I've posted in it before.

[Brumby]

Cheap playthings near Sydney 

eBay auction: #324848393872       
eBay auction: #324848242577   

..... and I don't have a TDR!

Nearly an hour each way by untolled roads or about half that time with an extra $27 in tolls.  I'm sorta tempted, but not sure if I'm that motivated.

Not to mention the reception upon return to the household.   

Contacted the seller with an offer for the two.  Seems the "Make an Offer" option wasn't meant to be there and has now been turned off.  Prices are fixed.  Will think about what I'm willing to sink into this.....  As it stands, we're talking about $100 total outlay (plus my time and petrol) for two items that have no guarantee.

Also, two pick up locations have been given - and I've asked for clarification on that.

[mansaxel]

The scope is loaded with germanium 2N2207 which are very prone to developing tin whisker shorts.

This was educational: https://w140.com/tekwiki/wiki/Germanium_transistors

[Brumby]

    ..... and I don't have a TDR!

  Note alteration above.


You lot happy now?

[med6753]

The scope is loaded with germanium 2N2207 which are very prone to developing tin whisker shorts.

This was educational: https://w140.com/tekwiki/wiki/Germanium_transistors

Yes, it is surprising that in most cases you can substitute a silicon transistor for a germanium transistor with no circuit changes. Early Type 547's used two germanium 2N2207's in the horizontal mag circuit. Later production changed them to silicon 2N4890 with no other changes.   

[McBryce]

Mentioning the need to re-cap the Fluke 8060A got me wondering about my similar vintage 8021B. How many electrolytics, if any, does it have? So I opened it up and took a look. Two. Both up to the bottom right of the LCD. And verified this via the parts list. Both 22uf/16V. When I do the re-cap of the 8060A I'll do this guy too.

Are you sure there's not more caps hidden under the display? The 8060 has a few there as far as I can remember.

McBryce.

[med6753]

    ..... and I don't have a TDR!

  Note alteration above.


You lot happy now?

Do you always give into peer pressure? 

[med6753]

Mentioning the need to re-cap the Fluke 8060A got me wondering about my similar vintage 8021B. How many electrolytics, if any, does it have? So I opened it up and took a look. Two. Both up to the bottom right of the LCD. And verified this via the parts list. Both 22uf/16V. When I do the re-cap of the 8060A I'll do this guy too.

Are you sure there's not more caps hidden under the display? The 8060 has a few there as far as I can remember.

McBryce.

Nope, as I stated I checked the parts list.

[tautech]

Anybody need tons of TE manuals ?

https://www.ebay.com/itm/10x15-Storage-unit-Test-Equipment-Manuals-several-thousand-Keysight-Agilent-/

 

eBay auction: #274980312189 use the item number and the ebay tag inserter works best. And NO I don't need to import these 

Don't tell Terahertz, he'll grab the lot ! 

What did I tell ya ? 
Now he's gotta get them all to Oz.
https://www.eevblog.com/forum/chat/urgent-request-for-us-west-coast-shipping-contacts/

Bean you're to blame for this !

[Brumby]

    ..... and I don't have a TDR!

  Note alteration above.


You lot happy now?

Do you always give into peer pressure? 

Only when I want to.   

[med6753]

Anybody need tons of TE manuals ?

https://www.ebay.com/itm/10x15-Storage-unit-Test-Equipment-Manuals-several-thousand-Keysight-Agilent-/

 

eBay auction: #274980312189 use the item number and the ebay tag inserter works best. And NO I don't need to import these 

Don't tell Terahertz, he'll grab the lot ! 

What did I tell ya ? 
Now he's gotta get them all to Oz.
https://www.eevblog.com/forum/chat/urgent-request-for-us-west-coast-shipping-contacts/

Bean you're to blame for this !

He is nuts. And willing to spend upwards of $20K to get them shipped to him. Wish I could throw $20K away and not even think about it. 

[beanflying]

    ..... and I don't have a TDR!

  Note alteration above.


You lot happy now?

Do you always give into peer pressure? 

Only when I want to.   

I didn't even point them in YOUR direction specifically either 

[Neper]

Here goes the rest of the assets from the former German IRT:

https://www.reich-bayern.de/de/objekte/au-116/liquidationsversteigerung_der_irt_institut_fuer_rundfunktechnik_gmbh_teil_2_-_ha?Lstatus=3

I'd like the HP counter and a few other things but all is pick-up only and driving to Munich is simply out of the question.

[Brumby]

    ..... and I don't have a TDR!

  Note alteration above.


You lot happy now?

Do you always give into peer pressure? 

Only when I want to.   

I didn't even point them in YOUR direction specifically either 

Hmmmmmmmmmm............