Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

Aaaaand BOOM:



PostMord handed the package over 5 minutes ago. Things work.

[bd139]

Nice. Got bugger all turned up here so far. Getting annoying as I've got about 11 things arriving. RM are supposed to be operating normally

[tggzzz]

This week's acquired treasure was a Cropico ESC1 1V voltage standard.

The output voltages < 6.9V can be derived by a simple resistive dividers; I avoided a similar device with a 10V output on the principal that I didn't want an op-amp's infelicities to get in the way of stability.

After leaving it in the garage for a couple of days, then removing all the packaging on the driveway and dumping it in the bin, then washing my hands, using readily available "undiluted hand sanitiser" on the case, I was finally able to look at it.

The positive and negative points from the auction photos can be seen: more tape residue than expected, but a "reference standard not to be removed from the stds room" sticker. The worry was that this was a battery only device powered by 18 1.5 D cells on top of the box, and that they might have leaked and gone everywhere. Looking around the back shows a jack socket marked 23V-27V. I wasn't expecting that since Cropico expected non-battery supplies would introduce noise. Since I don't have a corresponding plug, I'll temporarily connect a PSU to the battery terminals. Later I may make a nice low-noise 723 pre-regulator.



Anyway, time to take the top off, and... no worries - as clean as a whistle.



And on the inside of the lid...



The internals show neat wiring and a passive filter right by the outputs. I'm not going to open the black box unless absolutely necessary - too much chance of disturbing something. And the front panel cleans up nicely.





So, does it work? A quick comparison with my Fluke 515 shows the 1V is within a few µV. Anything more will require careful experiments.

Overall:

• excellent, looks like a winner
• does anyone have any info on the PT100 socket; there's more than 2 wires attached

FFI, there's more info here:
https://www.eevblog.com/forum/metrology/cropico-esc1-electronic-standard-cell-a-look-inside/
https://www.eevblog.com/forum/metrology/cropico-electronic-cell-power-supply/msg1254248/#msg1254248

[xrunner]

Urrk. I just slogged through about 45 minutes of tutorials; finally getting my hands learning how to poke around in Marlin firmware as used on my 3DP. I think my mind just boggled. 

LOL - if you have any questions I might be able to help. I've been playing with it and compiling it for mine for quite a while now. 

[AVGresponding]

This week's acquired treasure was a Cropico ESC1 1V voltage standard.

The output voltages < 6.9V can be derived by a simple resistive dividers; I avoided a similar device with a 10V output on the principal that I didn't want an op-amp's infelicities to get in the way of stability.

After leaving it in the garage for a couple of days, then removing all the packaging on the driveway and dumping it in the bin, then washing my hands, using readily available "undiluted hand sanitiser" on the case, I was finally able to look at it.

The positive and negative points from the auction photos can be seen: more tape residue than expected, but a "reference standard not to be removed from the stds room" sticker. The worry was that this was a battery only device powered by 18 1.5 D cells on top of the box, and that they might have leaked and gone everywhere. Looking around the back shows a jack socket marked 23V-27V. I wasn't expecting that since Cropico expected non-battery supplies would introduce noise. Since I don't have a corresponding plug, I'll temporarily connect a PSU to the battery terminals. Later I may make a nice low-noise 723 pre-regulator.



Anyway, time to take the top off, and... no worries - as clean as a whistle.



And on the inside of the lid...



The internals show neat wiring and a passive filter right by the outputs. I'm not going to open the black box unless absolutely necessary - too much chance of disturbing something. And the front panel cleans up nicely.





So, does it work? A quick comparison with my Fluke 515 shows the 1V is within a few µV. Anything more will require careful experiments.

Overall:

• excellent, looks like a winner
• does anyone have any info on the PT100 socket; there's more than 2 wires attached

FFI, there's more info here: https://www.eevblog.com/forum/metrology/cropico-esc1-electronic-standard-cell-a-look-inside/

I wonder if that 23-27V jack is for an external Plante cell battery, as that's the kind of range you'd expect from a 12 cell one.

[tggzzz]

This week's acquired treasure was a Cropico ESC1 1V voltage standard.
Looking around the back shows a jack socket marked 23V-27V. I wasn't expecting that since Cropico expected non-battery supplies would introduce noise. Since I don't have a corresponding plug, I'll temporarily connect a PSU to the battery terminals. Later I may make a nice low-noise 723 pre-regulator.

I wonder if that 23-27V jack is for an external Plante cell battery, as that's the kind of range you'd expect from a 12 cell one.

Unknown.

The manuals mention "dry Leclanche cells e.g. SP2" (i.e. zinc-carbon). Now 18*1.5V=27V, but it will work down to 23V. The "batteries low" light flashes at <21V.

Hence I suspect the external PSU spec is simply the same as you would get with the internal cells.

[Kosmic]

Nice. Got bugger all turned up here so far. Getting annoying as I've got about 11 things arriving. RM are supposed to be operating normally

Same here, waiting for usb panel mount connectors to finish my jim williams pulse generator 

[Kosmic]

• excellent, looks like a winner
• does anyone have any info on the PT100 socket; there's more than 2 wires attached

PT100 are normally measured with a 4 wires configuration. So I would expect 5 wires ? 4 wires for measurement and 1 for the shield ?

Just my guess.

[mnementh]

This week's acquired treasure was a Cropico ESC1 1V voltage standard.
Looking around the back shows a jack socket marked 23V-27V. I wasn't expecting that since Cropico expected non-battery supplies would introduce noise. Since I don't have a corresponding plug, I'll temporarily connect a PSU to the battery terminals. Later I may make a nice low-noise 723 pre-regulator.

I wonder if that 23-27V jack is for an external Plante cell battery, as that's the kind of range you'd expect from a 12 cell one.

Unknown.

The manuals mention "dry Leclanche cells e.g. SP2" (i.e. zinc-carbon). Now 18*1.5V=27V, but it will work down to 23V. The "batteries low" light flashes at <21V.

Hence I suspect the external PSU spec is simply the same as you would get with the internal cells.

This week's acquired treasure was a Cropico ESC1 1V voltage standard.
Looking around the back shows a jack socket marked 23V-27V. I wasn't expecting that since Cropico expected non-battery supplies would introduce noise. Since I don't have a corresponding plug, I'll temporarily connect a PSU to the battery terminals. Later I may make a nice low-noise 723 pre-regulator.

I wonder if that 23-27V jack is for an external Plante cell battery, as that's the kind of range you'd expect from a 12 cell one.

Unknown.

The manuals mention "dry Leclanche cells e.g. SP2" (i.e. zinc-carbon). Now 18*1.5V=27V, but it will work down to 23V. The "batteries low" light flashes at <21V.

Hence I suspect the external PSU spec is simply the same as you would get with the internal cells.

Sounds to me like a great candidate for a 6S pack of 18650 cells. At 25.2-19.8V normal operation; that 21V warning lamp would have them at ~3.5V/cell.  Drill packs often come in 6S configuration, but tend to be high current draw cells that will have some self-discharge considerations, however would be very compact, cheap & come in a convenient package, while already being in 6S configuration. Laptop packs often come in 2S3P configuration and would be a better source of matched cells with LSD characteristics. Unfortunately, both would come with controller circuitry that would likely add some noise; you'd need to strip that out to make a bare battery brick & balance charge with an external charger for best battery health.

mnem
 

[BU508A]

After reviewing this thread I believe I might have caught TEA. Please review for eligibility.

 

How long did it take you to read more than 53700 messages? 

Besides that: welcome to the TEA. From now on, you cannot leave or escape anymore.     

[mnementh]

Urrk. I just slogged through about 45 minutes of tutorials; finally getting my hands learning how to poke around in Marlin firmware as used on my 3DP. I think my mind just boggled. 

LOL - if you have any questions I might be able to help. I've been playing with it and compiling it for mine for quite a while now. 

Thanks... you may have signed up for a lot more tutoring than you planned.  I think I lost 90% of what I watched last night from mental fatigue; all the talk of Arduino IDE made me want to vomit... but looking again it appears newer versions use PlatformIO, which I know diddly about.    Not that I'd say I know jack shit about arduino IDE either...

Did I mention my kung-fu is weak...? 

mnem
*goes and kicks a sprite just on GP*

[AVGresponding]

Bah, f**k Sainsbury's and their feckwitted substitution policy.

Ordered 1.5L own brand vodka, and 1L Grants (I'm going to be stuck at home all weekend after all) and they have "no suitable substitute" for the whiskey, and are sending a 70cl bottle of Stoli as a sub for the vodka!   

In other words, they don't want to lose money by matching the quantity with a more expensive brand. Tesco's were never so skinflint, I regret moving to Sainsbury's in many ways.   

So I had to go out to my local Co-Op, which despite being much smaller than a main supermarket, had plenty, and I was able to get a litre of each with no problems. Unless you count the (small) queue of people in the car park outside due to the "one out, one in" policy to limit the number of people inside to 20 or so.

[xrunner]

Thanks... you may have signed up for a lot more tutoring than you planned.  I think I lost 90% of what I watched last night from mental fatigue; all the talk of Arduino IDE made me want to vomit... but looking again it appears newer versions use PlatformIO, which I know diddly about. 

You want to look at the printer tutorials that use VS Code and yes Platform IO. But most of it is under the hood so you will just be editing configuration.h and configuration_adv.h. I don't know if your board has a bootloader or not (the basic Enders didn't) so you might have to go down that rabbit hole before ... but once that is done it's a lot easier and you can start breaking it much faster and more efficiently. 

Anyway back to ordering food online ... 

[tggzzz]

This week's acquired treasure was a Cropico ESC1 1V voltage standard.
Looking around the back shows a jack socket marked 23V-27V. I wasn't expecting that since Cropico expected non-battery supplies would introduce noise. Since I don't have a corresponding plug, I'll temporarily connect a PSU to the battery terminals. Later I may make a nice low-noise 723 pre-regulator.

I wonder if that 23-27V jack is for an external Plante cell battery, as that's the kind of range you'd expect from a 12 cell one.

Unknown.

The manuals mention "dry Leclanche cells e.g. SP2" (i.e. zinc-carbon). Now 18*1.5V=27V, but it will work down to 23V. The "batteries low" light flashes at <21V.

Hence I suspect the external PSU spec is simply the same as you would get with the internal cells.

Sounds to me like a great candidate for a 6S pack of 18650 cells. At 25.2-19.8V normal operation; that 21V warning lamp would have them at ~3.5V/cell.  Drill packs often come in 6S configuration, but tend to be high current draw cells that will have some self-discharge considerations, however would be very compact, cheap & come in a convenient package, while already being in 6S configuration. Laptop packs often come in 2S3P configuration and would be a better source of matched cells with LSD characteristics. Unfortunately, both would come with controller circuitry that would likely add some noise; you'd need to strip that out to make a bare battery brick & balance charge with an external charger for best battery health.

I'm mildly irked that it is 21V. If it had been 20V then my very low noise Power Designs 2020B would have been ideal. As it is I might augment that with a single cell of some sort; only 18mA are needed.

Apart from that, I shy away from building anything with lithium cells. However, a drill pack and charger might be an option, iff I can get a connector for that. Regrettably my drill is only 18V

Overall I may well stay with a 723, possibly loosely affixed to the back.

[AVGresponding]

You could use a couple of cheap 12V SLA's, and disconnect them to charge them once a month or whenever.

[tggzzz]

You could use a couple of cheap 12V SLA's, and disconnect them to charge them once a month or whenever.

Yes, but I'd have to be careful they weren't >27V when reconnected.

I've got a 723, and I recently cobbled together a regulator for my HP 80111 OCXO, so it is familiar territory. Still open to options, though.

[AVGresponding]

You could use a couple of cheap 12V SLA's, and disconnect them to charge them once a month or whenever.

Yes, but I'd have to be careful they weren't >27V when reconnected.

I've got a 723, and I recently cobbled together a regulator for my HP 80111 OCXO, so it is familiar territory. Still open to options, though.

If they're that high they're gonna have a short lifespan!   

Many years of experience with these batteries has taught me to disregard the manufacturers data sheets for the most part.

You'll get 90% capacity or thereabouts charging them to 13.2V. I generally hit them up for 13.6V or so, but ofc the voltage drops as soon as you take them off charge.

I have found no benefit whatsoever in provoking them into equalisation, 13.8V or so and up, theoretically up to 15 or 16, in fact I never saw a battery that didn't die within a year from this treatment.

The proof of the pudding is in the eating they say, and I've SLA's that are 20+ years old (with reduced capacity, but still useful) due to not charging them at more than 13.6V and at a rate of less than C/10, preferably less than C/20.

[mnementh]

Sounds to me like a great candidate for a 6S pack of 18650 cells. At 25.2-19.8V normal operation; that 21V warning lamp would have them at ~3.5V/cell.  Drill packs often come in 6S configuration, but tend to be high current draw cells that will have some self-discharge considerations, however would be very compact, cheap & come in a convenient package, while already being in 6S configuration. Laptop packs often come in 2S3P configuration and would be a better source of matched cells with LSD characteristics. Unfortunately, both would come with controller circuitry that would likely add some noise; you'd need to strip that out to make a bare battery brick & balance charge with an external charger for best battery health.

I'm mildly irked that it is 21V. If it had been 20V then my very low noise Power Designs 2020B would have been ideal. As it is I might augment that with a single cell of some sort; only 18mA are needed.

Apart from that, I shy away from building anything with lithium cells. However, a drill pack and charger might be an option, iff I can get a connector for that. Regrettably my drill is only 18V

Overall I may well stay with a 723, possibly loosely affixed to the back.

The drill pack will have a controller/BMS circuit that must remain attached to charge using the OEM charger; this presents likelihood of noise. What I was suggesting was to buy the cheapest source of decent cells; Lowes Kobalt drills use a 1.5AH pack they used to sell for $10, but lately I've only seen the 2.0AH & 4.0AH at $25 & $50. Then add a 7-pin JST balance pigtail & charge using a inexpensive LiPo charger like the ISDT Q8 & be able to properly charge, diag & characterize any Lixx pack up to 8S(~$50) or you can even just get a decent balancer like the ISDT BG-8S (~$30) & charge using your existing CV/CC bench supply.

That said... with 150mA sink current (IIRC) vs your 20mA load... @ <$1, your LM723 solution is a lot cheaper. Makes me wonder why the MFR went to the hassle of using battery power, when the battery holder cost is probably ≥ the BOM for a 723 prereg assembly...?

mnem
 

[AVGresponding]

Noise and isolation, presumably.

[mnementh]

Yeah, that's where I was going widdat.

You could use a couple of cheap 12V SLA's, and disconnect them to charge them once a month or whenever.

Yes, but I'd have to be careful they weren't >27V when reconnected...

Much greater concern is that bd would come & mug you for them to power his QRP rig.

mnem
 

[bd139]

I've got stacks of them here. I think 9 at the moment. Yours are safe

[tggzzz]

Makes me wonder why the MFR went to the hassle of using battery power, when the battery holder cost is probably ≥ the BOM for a 723 prereg assembly...?

From the excellent "this is why" document that is so rarely seen:
https://www.eevblog.com/forum/metrology/cropico-esc1-electronic-standard-cell-a-look-inside/?action=dlattach;attach=208677



My other voltage reference is SLA and mains powered, and recommends measurement on battery power.

[AVGresponding]

Could always use a couple of these 100Ah jobbies like I have for my UPS.



They weigh 30kg or so a piece, can't see him jogging off down the road with a couple of those under his arms!   

[Cerebus]

It would appear that Europe is sleeping in this morning. 

Lazy wankers. 

I might remind you that we're operating on Greenwich (London) Mean Time, not Greenwich Village Grumpy Time. Anyway, shouldn't a man of your years be about ready to be tucked up with a glass of warm milk at this hour?

[grizewald]

Aaaaand BOOM:

(Attachment Link)

PostMord handed the package over 5 minutes ago. Things work.

PostMord? Didn't they send your order by FedEx?