Test Equipment Anonymous (TEA) group therapy thread

[Cerebus]

On the subject of food, this just out of the oven: one tarte tatin. Ingredients: flour, butter, apples, sugar, water, that is all.



(The colour balance is a bit off but I can't be arsed to fix it.)

[Specmaster]

Please refrain from posting picture of my sister 

Oh that's cruel.  Ex-wives are fair game but not your sister. Have a heart. 

I owe her that one after the elephant's arse comment 

Are you sure that you aren't just a tad worried that she might just try out one of her veterinary surgical skills on you 

[Specmaster]

On the subject of food, this just out of the oven: one tarte tatin. Ingredients: flour, butter, apples, sugar, water, that is all.



(The colour balance is a bit off but I can't be arsed to fix it.)

Looks delicious, a dollop of nice clotted ice cream on top would finish that off a treat. 

[tggzzz]

On the subject of food, this just out of the oven: one tarte tatin. Ingredients: flour, butter, apples, sugar, water, that is all.

(The colour balance is a bit off but I can't be arsed to fix it.)

Looks delicious, a dollop of nice clotted ice cream on top would finish that off a treat. 

Poor ice cream maybe, but it would be a waste of good ice cream.

Lemon and mint, or parma violet, or blueberry and spiced gin ice cream would not go harmoniously with that!

[Neper]

Good old tarte tatin. You might want to try it with pears instead of apple, for a change.

[mnementh]

   ...So I've got this neat model of an 3 phase induction motor.   

mnem
   

[AVGresponding]

   This is far superior. It measures consistently 2.35 to 2.40 milliohms "plug" to "plug". I tweaked the "plugs" for a gentle fit into a 4mm socket, it works well...

Plus you can stick it in a drill and whisk your omelettes on Sunday morning. 

mnem

Sacrilege! You beat the egg by hand, with a fork or a whisk, never with power tools!

[mnementh]

Sorry... my drill is variable speed. 

mnem
Besides... I'm saving that wrist action for more important stuff. 

[AVGresponding]

I was unhappy with the results I was getting testing the resistance across the banana plugs on that last design, they were very inconsistent, between about 80 microohms and 4 milliohms. I seriously doubt the credibility of the 80 microohms reading, I think I'm getting noise from the TE effect between the plug and wire, and some inconsistent contact also.

So I changed tack, and decided to make a short using only copper:



This is far superior. It measures consistently 2.35 to 2.40 milliohms "plug" to "plug". I tweaked the "plugs" for a gentle fit into a 4mm socket, it works well.


EDIT: The inductance between plugs measures <20nH, which is basically in the noise as far as this LCR meter is concerned.

Sorry if this is being stupid... why not simply take an oxy-acetylene torch and melt / fuse the 4 copper wires together ? That would make for a reliable and low impedance connection wouldn't it, and no TE effect. Just.. a blob of copper. 

Sure, I could try that. Do you have a spare oxy-acetylene torch I can borrow?

It wouldn't work though. Heating the copper like that would make it oxidise badly. You could try using a flux to stop that happening of course, but that would introduce more chemicals to the mix, no problem if you're welding, but likely very problematic in this use case. Not to mention what the heat cycling is likely to do to the electrical properties of the piece.

[AVGresponding]

Sorry... my drill is variable speed. 

mnem
Besides... I'm saving that wrist action for more important stuff. 

The speed is irrelevant. What is relevant is the loss of feel for the stiffness of the mix.

[Vince]

I was unhappy with the results I was getting testing the resistance across the banana plugs on that last design, they were very inconsistent, between about 80 microohms and 4 milliohms. I seriously doubt the credibility of the 80 microohms reading, I think I'm getting noise from the TE effect between the plug and wire, and some inconsistent contact also.

So I changed tack, and decided to make a short using only copper:



This is far superior. It measures consistently 2.35 to 2.40 milliohms "plug" to "plug". I tweaked the "plugs" for a gentle fit into a 4mm socket, it works well.


EDIT: The inductance between plugs measures <20nH, which is basically in the noise as far as this LCR meter is concerned.

Sorry if this is being stupid... why not simply take an oxy-acetylene torch and melt / fuse the 4 copper wires together ? That would make for a reliable and low impedance connection wouldn't it, and no TE effect. Just.. a blob of copper. 

Sure, I could try that. Do you have a spare oxy-acetylene torch I can borrow?

It wouldn't work though. Heating the copper like that would make it oxidize badly. You could try using a flux to stop that happening of course, but that would introduce more chemicals to the mix, no problem if you're welding, but likely very problematic in this use case. Not to mention what the heat cycling is likely to do to the electrical properties of the piece.

I don't have a torch because I don't have a garage, but as soon as the garage is built my old man will give all his tools, so the oxy-acetylene gear will be part of it 
Oxidization hmmm... would that not be limited to the surface of the blob ? Was hoping the core of the blob would still be pure copper. OK well, too bad uh... so TIG welding with a shielding gas it is then !
OK, if you don't have a torch, you probably don't have a MIG never mind a TIG.... back to square one... I am trying my best !

So get a MIG with a a tank of gas so that next time you are better prepared !

You live in an apartment, no garage/workshop ? OK I give up !

Looking at you picture, I am not sure the crimp is doing much at all does it ? The wires are twisted over such a long distance that I guess the total contact area between them is what makes for the good connection rather than the crimp at the very end ?  I bet if you just remove/cut crimp, the shunt would still measure just as good !

[mnementh]

Please refrain from posting picture of my sister 

Oh that's cruel.  Ex-wives are fair game but not your sister. Have a heart. 

I owe her that one after the elephant's arse comment 

I notice you're not disputing the statement... only exacting revenge. 

mnem
Bring it; I already know the shadow of my arse weighs 20 lbs...

Are you sure that you aren't just a tad worried that she might just try out one of her veterinary surgical skills on you 

Not in the least bit. 

mnem

   "Watch out! It is coming at you!!!"

[mnementh]

Sorry... my drill is variable speed. 

mnem
Besides... I'm saving that wrist action for more important stuff. 

The speed is irrelevant. What is relevant is the loss of feel for the stiffness of the mix.

My mix gets plenty stiff... with or without power tools. 

mnem
Besides... it's just omelette. Not crepe or something critical like that.

[capt bullshot]

[
mnem
   

Get a proper one:

[bd139]

Ok 3465A is now fixed. It was a leaky clamp diode. Would have never found it if the diode didn't fall to bits 

2N4117A subbed in as a diode connected FET as suggested by both HPAK and EEVblog forum members. Works perfectly, clamp works too.





Did DC and ohms cal. I don't have any test cables (  ) to do the AC cal yet.

Will update the other thread and HPAK group now

[Vince]

Mine is much cheaper, and much better credentials, sorry 
... and in search of a good home currently...

[mnementh]

mnem
   

Get a proper one:      

Gonna be really hard to make it fly with that one. 

The little one is already overkill by a factor of about 20, at least from your power readings. No idea what the draw would be like once you up the frequency tho.

mnem

[Cerebus]

Looks delicious, a dollop of nice clotted ice cream on top would finish that off a treat. 

It did! (Although it wasn't clotted cream ice cream, just plain old vanilla Hagen-Das.)

[Cerebus]

Good old tarte tatin. You might want to try it with pears instead of apple, for a change.

I have, and have to agree that they make a great tarte tatin. Peaches is good too. It was apples this time because I wanted to enjoy the last of the locally grown (Kent) apples before the season switches to almost all imported apples.

I'm actually just having another piece cold, and the remains will probably go with coffee for breakfast.

[Specmaster]

I was unhappy with the results I was getting testing the resistance across the banana plugs on that last design, they were very inconsistent, between about 80 microohms and 4 milliohms. I seriously doubt the credibility of the 80 microohms reading, I think I'm getting noise from the TE effect between the plug and wire, and some inconsistent contact also.

So I changed tack, and decided to make a short using only copper:



This is far superior. It measures consistently 2.35 to 2.40 milliohms "plug" to "plug". I tweaked the "plugs" for a gentle fit into a 4mm socket, it works well.


EDIT: The inductance between plugs measures <20nH, which is basically in the noise as far as this LCR meter is concerned.

Sorry if this is being stupid... why not simply take an oxy-acetylene torch and melt / fuse the 4 copper wires together ? That would make for a reliable and low impedance connection wouldn't it, and no TE effect. Just.. a blob of copper. 

Sure, I could try that. Do you have a spare oxy-acetylene torch I can borrow?

It wouldn't work though. Heating the copper like that would make it oxidize badly. You could try using a flux to stop that happening of course, but that would introduce more chemicals to the mix, no problem if you're welding, but likely very problematic in this use case. Not to mention what the heat cycling is likely to do to the electrical properties of the piece.

I don't have a torch because I don't have a garage, but as soon as the garage is built my old man will give all his tools, so the oxy-acetylene gear will be part of it 
Oxidization hmmm... would that not be limited to the surface of the blob ? Was hoping the core of the blob would still be pure copper. OK well, too bad uh... so TIG welding with a shielding gas it is then !
OK, if you don't have a torch, you probably don't have a MIG never mind a TIG.... back to square one... I am trying my best !

So get a MIG with a a tank of gas so that next time you are better prepared !

You live in an apartment, no garage/workshop ? OK I give up !

Looking at you picture, I am not sure the crimp is doing much at all does it ? The wires are twisted over such a long distance that I guess the total contact area between them is what makes for the good connection rather than the crimp at the very end ?  I bet if you just remove/cut crimp, the shunt would still measure just as good !

I suspect that because of the sheer size of the shorting plug and the fact that copper is such a brilliant conductor of heat, that the oxidizing could be restricted to just the "blob" zone. 

[hendorog]

The EMEX organisers felt very sorry for me having to spend three days in close confinement with tautech in the Siglent booth. So they gave me my own booth!!!

Of course being the upstanding gentleman I am, I let him use it....

[BU508A]

This stand needs definitely more Siglent TE. 

[hendorog]

This stand needs definitely more Siglent TE. 

Had to leave some room for the dance floor 

[Neomys Sapiens]

Alas, I got only 1 out of three - work did make me lose the TCP202 and an evil bidder the P6248. Dang. At least 1 HV differential probe for which I do not need batteries anymore. But a P5210 for a measly 279.- is a good catch already. Once I have at least one P5205 to go wih it (2 are target), I will sell off one or two of my non-Tek Isoprobes.
And I will have another go at a TCP202, it seems. I just hope that I did not tip that s*****g off with my cautionary post.

[med6753]

Ok 3465A is now fixed. It was a leaky clamp diode. Would have never found it if the diode didn't fall to bits 

2N4117A subbed in as a diode connected FET as suggested by both HPAK and EEVblog forum members. Works perfectly, clamp works too.





Did DC and ohms cal. I don't have any test cables (  ) to do the AC cal yet.

Will update the other thread and HPAK group now

Good deal. It's nice to see you back in the "groove".