Test Equipment Anonymous (TEA) group therapy thread

[Teti]

Really nice power trolley capt bullshot  Love it. Will make something similar in the future, although it would be nice to see flex instead of single insulated wires if you know what I mean.

[mnementh]

A little cheap corrugated loom will make that look right as rain, and easy to do after-the-fact. 

mnem
 

[Specmaster]

Also https://HVstuff.com

So went through all the junk boxes looking for a project today. Turns out I actually have enough crap lying around for a power supply so I'm building one, because why the hell not.  Will just stuff a 7812 and an LM317 in it on two separate outputs. Lame but is less than half the depth of an HP supply so it can be wedged somewhere



guts currently empty but the annoying bit (panel bashing) is done.

Also put an offer in on another Fluke 25 because quite frankly I like them, a lot.

Yep, get a pair of 25's and use them as wheel chocks, weights, etc when not using them as meters. Personally I'd be looking at a Fluke 27 to compliment the 25.

[Specmaster]

A Metrix MX202B meter might be available soon. Anybody interested?

25µA (i.e. 40kohms/V), big scale relative to case, quirky selection mechanism, Hg cell (but conversion kit available on fleabay!)

http://public.beuth-hochschule.de/hamann/MULTIMETER/mx202.html

Yeh, I might be if the price is right, Simon Spiers did one of those recently, rather quirky but nice.

[bd139]

Also https://HVstuff.com

So went through all the junk boxes looking for a project today. Turns out I actually have enough crap lying around for a power supply so I'm building one, because why the hell not.  Will just stuff a 7812 and an LM317 in it on two separate outputs. Lame but is less than half the depth of an HP supply so it can be wedged somewhere



guts currently empty but the annoying bit (panel bashing) is done.

Also put an offer in on another Fluke 25 because quite frankly I like them, a lot.

Yep, get a pair of 25's and use them as wheel chocks, weights, etc when not using them as meters. Personally I'd be looking at a Fluke 27 to compliment the 25.

You say that but I was going to use them as weights for upper body exercise 

[Specmaster]

Also https://HVstuff.com

So went through all the junk boxes looking for a project today. Turns out I actually have enough crap lying around for a power supply so I'm building one, because why the hell not.  Will just stuff a 7812 and an LM317 in it on two separate outputs. Lame but is less than half the depth of an HP supply so it can be wedged somewhere



guts currently empty but the annoying bit (panel bashing) is done.

Also put an offer in on another Fluke 25 because quite frankly I like them, a lot.

Yep, get a pair of 25's and use them as wheel chocks, weights, etc when not using them as meters. Personally I'd be looking at a Fluke 27 to compliment the 25.

You say that but I was going to use them as weights for upper body exercise 

You can still do that, 2 extra rubbery push button caps will only add about 10grams to the weight.

[Specmaster]

Yeh I know I said that it would be awhile before I get the PL310 on the bench and I'd some photos, and I still will do, when my bench is a bit more photogenic  , but I just couldn't wait any longer to see how it fared at the hands of DPD, it was perfect, well wrapped by Iced Tea,

Early indications show that I need a 2N3055 pass transistor and a 7805CT voltage regulator at least. I'll get those from Farnell and use up my credit note they gave instead of a refund for a returned item. While I have the power board out to replace the voltage regulator, I'll do a re-cap on it, 6 caps in total, 2 x 1000uF @ 63V, 1 x 1000uF @35V and 2 x 10uF @ 35V and I think it will be back in working order again.                                                                                                                                   

[Fungus]

oh, you just found an eddie in the space time continuum.

Who's Eddie?

"When Eddie said he didn't like his teddy...

I was thinking more of this one.

PS: I got yours before the end of the first line. 

[mansaxel]

Jeezus... you poor suffering bastard. I understand that it is safer overall... but the sheer volume of oversized plastic electrical connectors there is just... painful. 

mnem
Like watching a guy stuff 6 lbs in a 5lb sack.

The 416-6h plug carries over 10KW at rated load. At voltages that make sparkies in Leftpondia shit their pants. In my book, northern America has brought nothing even remotely worthy of consideration to the mains plug contest, ever.  I'd rather have the CEE plug than _anything_ concocted on the other side of the Atlantic, with the possible exception of MS-3016 and similar plugs.

Grown-up mains requires proper EU engineering, period.

Goes out in the garage and pats his 3-phase feeder, in a laughing fit over Hubbell toys

[mansaxel]

Also put an offer in on another Fluke 25 because quite frankly I like them, a lot.

Yep, get a pair of 25's and use them as wheel chocks, weights, etc when not using them as meters. Personally I'd be looking at a Fluke 27 to compliment the 25.

I'm sort of tempted by the 27, too. I don't need it, but I want it.

[BU508A]

I will not make it to discord this evening. Today, some friends and me have cleared the house of our friend Obri which died in May this year because of a cerebral haemorrhage. He was clearly suffering from TEA and it took ages to go through all this stuff. *uff*

When I went home, I got for my collection

- a Keithley 2100
- a Fluke 8845A
- and some scope tubes of various sizes. Must check them tomorrow.

Pictures will follow.
Now I'm dead for the rest of the day and a huge part of the Sunday.
Sometimes, I wish I would be 20yo again...

[Specmaster]

I will not make it to discord this evening. Today, some friends and me have cleared the house of our friend Obri which died in May this year because of a cerebral haemorrhage. He was clearly suffering from TEA and it took ages to go through all this stuff. *uff*

When I went home, I got for my collection

- a Keithley 2100
- a Fluke 8845A
- and some scope tubes of various sizes. Must check them tomorrow.

Pictures will follow.
Now I'm dead for the rest of the day and a huge part of the Sunday.
Sometimes, I wish I would be 20yo again...

Yes, I also and I suspect most of us older generation folks on here also would like to be 20 again, I know for certain that I'd love to be that age again right now. Sad to hear about your friend, but at the very least you have something to enjoy that was his and to always remind you of him, enjoy your weekend.

[Specmaster]

I may not join in on tonight's discord meeting, I have a bit of discovering to do with Covid-19 testing centres, a member of my very close family needs a test and it seems almost impossible to get any real information about where and when a test can be got or even arranged 

[mnementh]

Jeezus... you poor suffering bastard. I understand that it is safer overall... but the sheer volume of oversized plastic electrical connectors there is just... painful. 

mnem
Like watching a guy stuff 6 lbs in a 5lb sack.

The 416-6h plug carries over 10KW at rated load. At voltages that make sparkies in Leftpondia shit their pants. In my book, northern America has brought nothing even remotely worthy of consideration to the mains plug contest, ever.  I'd rather have the CEE plug than _anything_ concocted on the other side of the Atlantic, with the possible exception of MS-3016 and similar plugs.

Grown-up mains requires proper EU engineering, period.

Goes out in the garage and pats his 3-phase feeder, in a laughing fit over Hubbell toys

Maybe... but we can walk around inside our office without needing to wear steel-toed boots in case a power strip gets knocked onto the floor. 

mnem
 

[bd139]

I may not join in on tonight's discord meeting, I have a bit of discovering to do with Covid-19 testing centres, a member of my very close family needs a test and it seems almost impossible to get any real information about where and when a test can be got or even arranged 

Good luck with that. It's a complete shit show from what I understand.

[URI]

My project of an properly isolated T12 soldering station has started. 

Yesterday all missing components except -of course- the T12 controller (comes from china) were delivered.

Today I searched the rubbish I have laying around in my workshop and around my bench and started to build the power supply into the housing. The housing is 240mm deep, 160mm wide and 120mm high.
I will use it 90° rotated so that it's then 120mm wide and 160mm wide.

The power supply is made of a toroid isolation transformer with an inrush current limiter followed by a full bridge rectifier and 2x47mF caps supplying a DC to DC converter with 24V/5A output for the T12 controller.

Progress so far is: The toroid transformer is mounted at its final position with primary wiring and inrush current limiter completed.
The mounting bracket that the DC to DC converter will be mounted to is fitted in. It will also carry the bridge rectifier and the two caps.

That's what it's looking like at this stage:


The DC to DC converter and caps are only loosely put in their final position to show how it'll be when it's finished.

[Specmaster]

I may not join in on tonight's discord meeting, I have a bit of discovering to do with Covid-19 testing centres, a member of my very close family needs a test and it seems almost impossible to get any real information about where and when a test can be got or even arranged 

Good luck with that. It's a complete shit show from what I understand.

Yes you're right. My sons boss who share the same office has tested positive and is in self-isolation. It seems that all the rest of the staff can do now is to self-isolate for the required period. Testing can be had free only if you are actually displaying the symptoms. Such tests are by appointment only and then you have to go to test centre which could be miles away, if you can get a test booked which are time sensitive, so you cannot afford to be late. You can of course get a private test done by doctors willing to do them for £195 for the swab test, or £130 for the blood test to see if you have the antibodies in your blood.

Is it any wonder that cases continue to rise across the country, the whole system is a stinking cesspit of corruption and lies continue to pour from the Governments lips daily about how wonderful the centres and tests are and how we have a world beating system 

[Specmaster]

My project of an properly isolated T12 soldering station has started. 

Yesterday all missing components except -of course- the T12 controller (comes from china) were delivered.

Today I searched the rubbish I have laying around in my workshop and around my bench and started to build the power supply into the housing. The housing is 240mm deep, 160mm wide and 120mm high.
I will use it 90° rotated so that it's then 120mm wide and 160mm wide.

The power supply is made of a toroid isolation transformer with an inrush current limiter followed by a full bridge rectifier and 2x47mF caps supplying a DC to DC converter with 24V/5A output for the T12 controller.

Progress so far is: The toroid transformer is mounted at its final position with primary wiring and inrush current limiter completed.
The mounting bracket that the DC to DC converter will be mounted to is fitted in. It will also carry the bridge rectifier and the two caps.

That's what it's looking like at this stage:


The DC to DC converter and caps are only loosely put in their final position to show how it'll be when it's finished.

Looking good, but I can't help thinking that it's a sledgehammer to crack a peanut. Surely all you needed to do was to buy standard mains driven T12 package from China, like a Quicko T12-952 which I have and plug that into a suitable main's isolation transformer, cheaper, quicker and smaller on the bench?

[URI]

My project of an properly isolated T12 soldering station has started. 

Yesterday all missing components except -of course- the T12 controller (comes from china) were delivered.

Today I searched the rubbish I have laying around in my workshop and around my bench and started to build the power supply into the housing. The housing is 240mm deep, 160mm wide and 120mm high.
I will use it 90° rotated so that it's then 120mm wide and 160mm wide.

The power supply is made of a toroid isolation transformer with an inrush current limiter followed by a full bridge rectifier and 2x47mF caps supplying a DC to DC converter with 24V/5A output for the T12 controller.

Progress so far is: The toroid transformer is mounted at its final position with primary wiring and inrush current limiter completed.
The mounting bracket that the DC to DC converter will be mounted to is fitted in. It will also carry the bridge rectifier and the two caps.

That's what it's looking like at this stage:


The DC to DC converter and caps are only loosely put in their final position to show how it'll be when it's finished.

Looking good, but I can't help thinking that it's a sledgehammer to crack a peanut. Surely all you needed to do was to buy standard mains driven T12 package from China, like a Quicko T12-952 which I have and plug that into a suitable main's isolation transformer, cheaper, quicker and smaller on the bench?

You're right basically.
But the AC to DC switching power supply would still be full of flaws -it's also not built to be operated with an isolated 230V AC because its housing is metal and has to be earthed therefore.
My solution was to build my own isolated switching power supply according to safety standards and combine that with a T12 controller -I've ordered the one in the short case with 24V/3A input.
I won't be paying for a switch mode power supply with an insulation based on the solder mask only.    

edit: and, yes -it's a a bit overdone.
I saidwrote earlier this is getting out of control a bit because the power supply costs way more than the T12 controller..   

edit²: Ah, and this power supply also solves the problem of the light T12 cases being pushed away easily when pressing the rotary encoder button. Mine won't be moving a millimetre.   

[Neomys Sapiens]

@URI: but sizewise the outcome is such, that I would have expected it to provide 24V 5A LINEAR. Except that part of it would need to be a heatsink. But why do you use an isolated converter behind that isolation transformer?

[mnementh]

Yeah; for reallzz. Talk aboot stuffing 6lbs in a 5lb sack! 

All you need is a 120VA 24V transformer. Rectify, a little brute force filtration, add sufficient resistive load to bring bring DCV down to 28V at idle, or build a simple linear regulator. Add your usual 1MΩ ESD bleeder between cartridge barrel and the GND tab and you're golden.

KISS principle; seriously.

mnem
Typical German engineering... why use 5 parts to do something, when 50 can do the job just as well...?  

[URI]

Believe me, there has been serious thoughts on my side building the power supply that way.

1. Isolation:
My first approach was to just take an off shelf switch mode power supply. That would have provided an isolation one could be sure of not to be killed by it someday.
BUT:
These switchers do have capacitive voltages to ground, the output isn't floating as freely as one would assume; A CMOS circuit could be offended by that and decide to go dying...   

Second approach: Isolation using a transformer. Choosing a transformer that is certified for SELV/PELV circuits on the secondary side would give me the isolation safely that I need without switch mode residual voltages to ground.
In fact, the older Weller station with two wire input, fully isolated case and a transformer do exactly that.

Conclusion: Building a fully isolated power supply with two wire mains connection built in an fully isolated case.
This is a concept of double isolation (like the Weller stations I mentioned above) and protects the user from touching any mains parts or parts that could carry mains if a failure occurs.

This means that I would build the station into a plastic case -and that can't be used a heat sink..

2. Regulation
I bought the KSGER T12 controller.
I researched the net a bit and found Information that this T12 controller stands ~25V ok.
The KSGER switch mode power supply doesn't exactly output 24V, indeed.
But above 26V it seems to quickly die.   
IIRC that was the result of someone trying to speed up heating by increasing the voltage..   

This led to...

3. Voltage Regulation
A linear regulator is so inefficient that it would produce a massive amount of heat that I would have to cope with.
Since I build the station in a plastic case getting the heat out would be a major problem making it even more complex.   
 
The DC to DC switch mode converter has an efficiency of over 90% and it doesn't heat much when idle -unlike a linear supply.   

I do not need an isolated DC to DC switcher but when it comes that way, why not.

The most important feature of this DC to DC switch mode converter for me is that it doesn't need an earth connection when powered with an isolated voltage.

4. ESD-compatability:
For ESD-compatibility I need a proper isolation transformer. -check.   
Since the tip is then properly isolated and floating I will add a 4mm socket connected to the tip to be able to connect to my ESD hub. Or to earth. Or to whatever.
It's most simple and flexible to just add a connector.

Now, when it comes to German engineering:
My solution in every part is not optimized to size, weight, volume, price or power needs.
You could say it's oversized in every part, yes.
A manufacturer would have managed to put this in a case 1/4 of the volume exactly fitted power wise.

Since I used off-shelf parts I had to over-dimension the single stages:
The T12 controllers mostly come with a 24V/5A supply even though the controllers without supply have a DC input marked with 24V/3A.
I chose a 24V/5A DC to DC converter because I wanted to have the same power like the standard KSGER supply.

I couldn't find matching isolation transformers with 120VA rated power. So I went for one with 160VA rated power.

The two big caps are dimensioned to filter the rectified DC voltage under full load (5A) to under a volt ripple.   
I just like those big cans.   

mnem: This is the minimal count of parts using non-optimized off-shelf parts. It's not the cheapest and elegant way, though.   

[Specmaster]

@URI, I don’t know which model of T12 power supply you’ve looked at but on mine solder mask is not being used as the means of isolation. The psi sits in 2 channels on the side walls close to the bottom, there is a gap of around 6mm between the trace side of psi and metal case and in this gap there a piece plastic insulation. Granted there are 2 tracks that actual go into channels, and run the length of the pub. I was concerned about this myself as the case was not earthed so I investigated further and found that those 2 tracks in the channels were in carrying the earth connection from the rear terminals to the front to earth the socket and iron tip. Therefore I concluded that the only modification needed was to bond all the metal case parts to each other and the main incoming earth connection.

I have had mine now for 2 years and have never had any trouble with them at all and I have worked on many sensitive parts with the iron connected to the house ground and have not destroyed anything yet.

As to the case moving on the bench when using the rotary encoder, I have not found that to be a major issue as I fitted 4 small rubber feet to bottom of mine and find they grip the bench pretty well.

EDIT.
I just read your reply above, there is no point in providing a earthed lead to the tip that you can then connect to your ESD mat or to house ground since that require a return path to the leakage voltage source that your trying to eliminate. There will not be a path for this leakage to dissipate to 

[med6753]

In the category of wishful thinking.....

https://hudsonvalley.craigslist.org/ele/d/olivebridge-vintage-heathkit-audio/7197056113.html

It's in good shape. But not $100 USD good shape. More like $30 USD tops. And he's wrong on the date. Case style puts it into the 1970's.

I'd educate him but his town is kinda far and I'm not really interested so I'd most likely just piss him off. 

[Robert763]

Believe me, there has been serious thoughts on my side building the power supply that way.

1. Isolation:
My first approach was to just take an off shelf switch mode power supply. That would have provided an isolation one could be sure of not to be killed by it someday.
BUT:
These switchers do have capacitive voltages to ground, the output isn't floating as freely as one would assume; A CMOS circuit could be offended by that and decide to go dying...   

Second approach: Isolation using a transformer. Choosing a transformer that is certified for SELV/PELV circuits on the secondary side would give me the isolation safely that I need without switch mode residual voltages to ground.
In fact, the older Weller station with two wire input, fully isolated case and a transformer do exactly that.

Conclusion: Building a fully isolated power supply with two wire mains connection built in an fully isolated case.
This is a concept of double isolation (like the Weller stations I mentioned above) and protects the user from touching any mains parts or parts that could carry mains if a failure occurs.

This means that I would build the station into a plastic case -and that can't be used a heat sink..

2. Regulation
I bought the KSGER T12 controller.
I researched the net a bit and found Information that this T12 controller stands ~25V ok.
The KSGER switch mode power supply doesn't exactly output 24V, indeed.
But above 26V it seems to quickly die.   
IIRC that was the result of someone trying to speed up heating by increasing the voltage..   

This led to...

3. Voltage Regulation
A linear regulator is so inefficient that it would produce a massive amount of heat that I would have to cope with.
Since I build the station in a plastic case getting the heat out would be a major problem making it even more complex.   
 
The DC to DC switch mode converter has an efficiency of over 90% and it doesn't heat much when idle -unlike a linear supply.   

I do not need an isolated DC to DC switcher but when it comes that way, why not.

The most important feature of this DC to DC switch mode converter for me is that it doesn't need an earth connection when powered with an isolated voltage.

4. ESD-compatability:
For ESD-compatibility I need a proper isolation transformer. -check.   
Since the tip is then properly isolated and floating I will add a 4mm socket connected to the tip to be able to connect to my ESD hub. Or to earth. Or to whatever.
It's most simple and flexible to just add a connector.

Now, when it comes to German engineering:
My solution in every part is not optimized to size, weight, volume, price or power needs.
You could say it's oversized in every part, yes.
A manufacturer would have managed to put this in a case 1/4 of the volume exactly fitted power wise.

Since I used off-shelf parts I had to over-dimension the single stages:
The T12 controllers mostly come with a 24V/5A supply even though the controllers without supply have a DC input marked with 24V/3A.
I chose a 24V/5A DC to DC converter because I wanted to have the same power like the standard KSGER supply.

I couldn't find matching isolation transformers with 120VA rated power. So I went for one with 160VA rated power.

The two big caps are dimensioned to filter the rectified DC voltage under full load (5A) to under a volt ripple.   
I just like those big cans.   

mnem: This is the minimal count of parts using non-optimized off-shelf parts. It's not the cheapest and elegant way, though.   

You don't have to put a SELV transformer in a plastic enclosure. put it in a metal box and connect that to ground but keep the secondary isolated. If you want to keep the iron tip seperate from the mains earth just bring it out via a series resistor to a 4mm socket for connection to the ESD station ground. The is no reason not to connect it to mains earth via a high resistance.

If you really want isolation but a 24V batter and charger in a box with the battery powering the soldering station and connected to the mains charger by a two pole relay. Relay coil connected to a switch on the iron holder so when you lift the iron only the batery is connected.  Also gives you a portable option.

Switch on the holder reminds me of the old trick of putting a diode in series with a non TC iron when in the holder so it does not over heat when sitting idle.