Exploring what's inside a 1980's milliohmmeter and how does it work, repairing it. Please support my channel on Patreon: / diodegonewild Instagram: / savage_danyk
What a beast of machine! Amazing! Thanks for bring to us this kind of content, definitely nothing you see on UA-cam on a regular basis, very interesting content. I hope you get better soon!
Thanks so much for letting us see it work; hard-setting the range was a good idea. This would have been a fairly expensive device with very few built and it uses so much current that it was obviously meant for a particular purpose with high-power shunts or wires. Sorry that you've been sick. I know a ton of people that are getting it recently here in the U.S. (central Kentucky), so I guess that no one is getting shots anymore . It put my cousin in the hospital.
Interesting unit. it looks like a ductor set to check across connection points of equipment and get readings in milli-Ohms. Interesting to have Nixie tubes and LED's in the same unit.
This was quite common back then - individual LEDs were much more available than LED displays. Also 1 out of 10 decoders were easier to get, because Tesla produced them, while 7-segment decoders had to be imported from East Germany.
I knew you would appreciate it, all of a sudden, it appeared in the warehouse that we use for storing discarded electronics in our company, ultimately it would end up taken to the scrap heap anyway
I never taught there was resistance meters like that (which can supply that much current, just for mesuring) - indeed useful to measure things like cables under load (getting the effect of the temperature rise included as well). Very interesting!🙂👍
Found something similar, a "microohmmeter" in a lab, with a variac, big screw terminals, and an LCD display, but this one went up to 600 A at maybe 2 V or so... Good for melting the cables under test if you were unhappy about their resistance.
This thing already has all the expensive parts necessary for converting it into a nice AC power supply - just remove the electronics and add a 230/230V isolation transformer and some switches. That would give 0-230V and 0-12V isolated from mains. Add some lightbulbs with different wattages and some more switches and it could also be used as a dim bulb tester for troubleshooting / restoring old radios etc.
Thanks for the great videos! There is actually an old trick to read the ratio of two voltages: use the normal input and reference input of the DMM/ADC. This is for example possible with the old ICL7107 and similar chips. For an ohmmeter you would put the sensed voltage into the input and sensed current converted to a voltage into the reference input instead of a constant voltage. If AC, it would need rectification of course. Constant current would be the other way :) Fun to see the manual feedback loop in this instrument. Very creative design! Love it...
Maybe the variac together with that LED scale was used to set a known voltage drop across measured resistance, and then it calculated the resistance based on current shunt's voltage drop (and thus the flowing current)?
Actually, the only difference to a modern 10A interference filter capable of filtering relatively low frequencies in addition to relatively high ones would be a soldered stamped sheet metal casing of the newer one (I guess, far east and western produced ones would be of the same cheaper case construction even 40 years ago) which would be a nightmare to review and repair. Anyway, a phase regulated large inductance will always require such a large filter.
Прибор для проверки переходного сопротивления контактов выключателей и т.п., одна из его особенностей - прогрузка контактов током, т.к. это важно для определения их степени износа.
This reminds me about the first high voltage lab power supply made in ussr that called уип-1 it was a tube power supply and it's weight was 46 kilo This was a thing of many purposes - you can generate some high voltage with it, or it could be used as a projectile to break heavy fortifications....
Sorry to hear that the creature has returned uninvited, I hope you feel better soon. What a complex piece of kit. If you don't have a use for it, I'm sure there are some salvageable components
I think it modify the reference voltage of the panel voltmeter accordingly to the current of measurement so it measure the voltage over current ratio instead of the external voltage over the reference voltage
Really nice video as always! One day can you make a video where you modify the 24V 10A power supply into an adjustable one? In one of your videos 4 years ago you said that you will try to make it adjustable but it never happened, maybe you forgot it or it was not worth it... (Dont worry at all!). I was interested on how to modify power supplies because it can be really useful for DIY. Can the voltage even set to be higher like 40V? Anyway i learned so much on this channel so big thanks for all the effort you put in your videos to teach us electronics! Keep it up 😉
Ďakujem za toto video, prístroj ma zaujal, najmä preto že má digitróny (podľa mňa najkrajší typ displejov) a pripomína to amatérsku výrobu, trúfam si povedať, že podobným štýlom bastlím rôzne zariadenia aj ja, akurát nie sú až také veľké a ťažké 😀. Je to pekná ukážka ľudovej tvorivosti ako sa bastlilo z toho, čo bolo zrovna k dispozícií.
Nice vid as always 👍 On one side, I would say leave it as it is since it seems to be pretty rare (judging from the fact that you didn't find any info on it), but on the other side, just letting it sit around collecting dust also seems like a waste. Maybe you can find a way to use it for something useful the way it is. But nonetheless, it definitely is an interesting piece of kit. I'm honestly curious what it was originally used for. Maybe it was used in a factory where shunts were produced to ensure that they are in spec.
This kind of milliohm measuring devices were designed to give reliable protective earth resistance or contact resistance results in high power devices or networks. The measurement can show low resistance with 0.1A or 1A, indicating good contact, but totally fail at e.g. 80A. So these test the circuit with real current level. These are not designed to measure resistors (like current shunts), even they can be used also for that purpose (of course only if the resistor withstands the test current). Quite expensive devices btw.
It seems like such a weird way of operating this machine. They already went to the effort of putting 30kg worth of stuff in there, and every kind of component imaginable is somewhere in there, and yet they did NOT put in a small motor to turn the variac for you instead of the LEDs... Just a simple dc motor and a couple power transistors driving it linearly would have completely automated the measurement, but no, they make the user do that job instead.
17:50 How much would such a meter go for these days? I'm sure that some kind of lab with no space issues might have a use for one - this thing looks like it's built to last 50 or 60 years, unless of course someone drops it...
Yes, not the most useful of test gear (outside of a power station perhaps??). But like a lot of fellow enthusiasts salivating over the wonderland array of functionable discrete components and bomb proof hardware🙂
The uA725 (MAA725?) Is a low drift low offset instrumentation amp. They were hard to come by back in the days... To be honest its a very stupid design using high current over a long time. A more intelligent approach would be to use a storage cap for providing the high current but only for milliseconds , discharging it via a constant current load through the DUT. A simple max detector would hold the measured shunt voltage. Everything would be 28 kilos lighter 😆
Unless the point of the device was to measure resistance under continuous high current, taking into account the resistance change caused by associated heating. (Consider e.g. measuring resistance of a cable that will be used for 80A. You'd then want to actually pass 80A through it.) I'm not sure though if the duration of measurement was sufficient for that.
As someone currently suffering from some sort of energy sapping virus (probably the same one), I really felt for you struggling to care about fixing it. Somehow I knew you would though, you can't keep a good man down!
@@DiodeGoneWild about the creature, sounds funky, because here on Brazil we haven't heard about a single case in ages. I started to thought they finally got it eradicated.
Great methodical troubleshooting; imagine if the device was packed properly and the switch wasn't broken in shipping. I have 6 variacs, one even goes from zero to 240 vac! Keep your videos, including the excellent comments from your cat, coming. By the way, what is your cat's name?
Get well soon man.
What is the illness?
@@supercompooper the creature. The one we all put our lives on pause for a couple of years ago.
What a beast of machine! Amazing! Thanks for bring to us this kind of content, definitely nothing you see on UA-cam on a regular basis, very interesting content. I hope you get better soon!
Thank you for appreciating a content which goes agains the mainstream fashion ;)
Thanks so much for letting us see it work; hard-setting the range was a good idea. This would have been a fairly expensive device with very few built and it uses so much current that it was obviously meant for a particular purpose with high-power shunts or wires.
Sorry that you've been sick. I know a ton of people that are getting it recently here in the U.S. (central Kentucky), so I guess that no one is getting shots anymore . It put my cousin in the hospital.
I mean if the shots worked.....
@@Ammoniummetavanadate They seem to work well at unaliving folks.
@@TechGorilla1987Real 💀
I wish you the best man, get well soon!
Thank you for educating and entertaining us for all these years
yo i see you
@@blockcamp stop stalking me haha
@@janno288 lolol love you man
I'm drooling over that variac too...
Interesting unit. it looks like a ductor set to check across connection points of equipment and get readings in milli-Ohms. Interesting to have Nixie tubes and LED's in the same unit.
This was quite common back then - individual LEDs were much more available than LED displays. Also 1 out of 10 decoders were easier to get, because Tesla produced them, while 7-segment decoders had to be imported from East Germany.
Thanks for your explanation. Great device anyway.@@DiodeGoneWild
I knew you would appreciate it, all of a sudden, it appeared in the warehouse that we use for storing discarded electronics in our company, ultimately it would end up taken to the scrap heap anyway
I never taught there was resistance meters like that (which can supply that much current, just for mesuring) - indeed useful to measure things like cables under load (getting the effect of the temperature rise included as well). Very interesting!🙂👍
Found something similar, a "microohmmeter" in a lab, with a variac, big screw terminals, and an LCD display, but this one went up to 600 A at maybe 2 V or so... Good for melting the cables under test if you were unhappy about their resistance.
This looks like old, big part of czechoslovakian atomic power plant! And it is great! I want more stuff like that :D
A thing of beauty and a joy for ever from our side of the Iron Curtain! And indeed, what's there not to drool over in the variac?
Wow that's a beast 😂, get well soon Dany
What a beautiful piece of kit! Very nice nixie tube display.
This thing already has all the expensive parts necessary for converting it into a nice AC power supply - just remove the electronics and add a 230/230V isolation transformer and some switches. That would give 0-230V and 0-12V isolated from mains. Add some lightbulbs with different wattages and some more switches and it could also be used as a dim bulb tester for troubleshooting / restoring old radios etc.
You could even Re-use the Nixie Voltmeter.
Thanks for the great videos! There is actually an old trick to read the ratio of two voltages: use the normal input and reference input of the DMM/ADC. This is for example possible with the old ICL7107 and similar chips. For an ohmmeter you would put the sensed voltage into the input and sensed current converted to a voltage into the reference input instead of a constant voltage. If AC, it would need rectification of course.
Constant current would be the other way :) Fun to see the manual feedback loop in this instrument. Very creative design! Love it...
Maybe the variac together with that LED scale was used to set a known voltage drop across measured resistance, and then it calculated the resistance based on current shunt's voltage drop (and thus the flowing current)?
What a nice but heavy piece of work! A genius can always repair even complicated electronics - nice to see!
WOW, congrats to find the issue.
a cold solder joint @ 23:46 on the daughter board, top left
Do you watch it in 8K on BIG screen?
On smartphone i barely can't differ it from just beeing crusty flux or dirt
I like the phrase "I caught the creature"
Big Thanks for sharing another Equipment and explaining its function.
Hopefully to fix your creature will be easy as the switch
TPW Thalheim made test equipment at one point along with special purpose transformers. Apparently they were once part of AEG.
Get better soon, I have the same variac in blue and 5 kVA, it's really nice one!! Thumbs up 👍😎😎
Another awesome video, thank you. 👍
Its amazing how much they went around the houses back in the day!!
Actually, the only difference to a modern 10A interference filter capable of filtering relatively low frequencies in addition to relatively high ones would be a soldered stamped sheet metal casing of the newer one (I guess, far east and western produced ones would be of the same cheaper case construction even 40 years ago) which would be a nightmare to review and repair. Anyway, a phase regulated large inductance will always require such a large filter.
Incredible work (as always). I wish I could reach your level of knowledge one day
Thanks for your support ;). I'm sure you will!
Get well soon!
It was such a nice machine with high quality components!
Thanks ;) I've recovered.
Nice work!
Прибор для проверки переходного сопротивления контактов выключателей и т.п., одна из его особенностей - прогрузка контактов током, т.к. это важно для определения их степени износа.
Pretty interesting meter!
Get well soon!
This reminds me about the first high voltage lab power supply made in ussr that called уип-1
it was a tube power supply and it's weight was 46 kilo
This was a thing of many purposes - you can generate some high voltage with it, or it could be used as a projectile to break heavy fortifications....
Sorry to hear that the creature has returned uninvited, I hope you feel better soon. What a complex piece of kit. If you don't have a use for it, I'm sure there are some salvageable components
I think it modify the reference voltage of the panel voltmeter accordingly to the current of measurement so it measure the voltage over current ratio instead of the external voltage over the reference voltage
Really nice video as always!
One day can you make a video where you modify the 24V 10A power supply into an adjustable one? In one of your videos 4 years ago you said that you will try to make it adjustable but it never happened, maybe you forgot it or it was not worth it... (Dont worry at all!). I was interested on how to modify power supplies because it can be really useful for DIY. Can the voltage even set to be higher like 40V?
Anyway i learned so much on this channel so big thanks for all the effort you put in your videos to teach us electronics!
Keep it up 😉
👍Thank you sir.
Ďakujem za toto video, prístroj ma zaujal, najmä preto že má digitróny (podľa mňa najkrajší typ displejov) a pripomína to amatérsku výrobu, trúfam si povedať, že podobným štýlom bastlím rôzne zariadenia aj ja, akurát nie sú až také veľké a ťažké 😀. Je to pekná ukážka ľudovej tvorivosti ako sa bastlilo z toho, čo bolo zrovna k dispozícií.
Perseverance!
Awesome !....cheers.
That's one beast of a super low resistance meter.
Somehow i think no one will steal it, too dam heavy.
Nice!
*Historical Electronic's BOX 😂😅👍🏻😊*
Nice vid as always 👍
On one side, I would say leave it as it is since it seems to be pretty rare (judging from the fact that you didn't find any info on it), but on the other side, just letting it sit around collecting dust also seems like a waste.
Maybe you can find a way to use it for something useful the way it is. But nonetheless, it definitely is an interesting piece of kit.
I'm honestly curious what it was originally used for. Maybe it was used in a factory where shunts were produced to ensure that they are in spec.
Yeah... I agree with the cat! "he's just drooling over that variac".
This kind of milliohm measuring devices were designed to give reliable protective earth resistance or contact resistance results in high power devices or networks.
The measurement can show low resistance with 0.1A or 1A, indicating good contact, but totally fail at e.g. 80A. So these test the circuit with real current level.
These are not designed to measure resistors (like current shunts), even they can be used also for that purpose (of course only if the resistor withstands the test current).
Quite expensive devices btw.
Get well soon please my idol
@4:53 - Czech that out!! Nice.
Now when someone gives you a boat you have the anchor for it already.
By any chance do u also go by the name pfred1 and more recently pfred2?
It seems like such a weird way of operating this machine. They already went to the effort of putting 30kg worth of stuff in there, and every kind of component imaginable is somewhere in there, and yet they did NOT put in a small motor to turn the variac for you instead of the LEDs... Just a simple dc motor and a couple power transistors driving it linearly would have completely automated the measurement, but no, they make the user do that job instead.
At 30 kg, that's a certifiable chonker! Lots of iron in there.
Yes I know, we should try to fix things, but... Its full of useful Parts!🤔
1:20 I thought something came unplugged from my computer, the sound... 😆
The LED's must be an add on, the other componants (nixie tubes etc) pre date Green LED's from memory.
Green LEDs already existed in 1989 when this was made, but the nixies were a bit obsolete. But still used here.
That transformer is enormous, are you sure it is not an arc welder in fact ? 😅
What a yourney... ❤🎉
Thank you for your support ;)
17:50 How much would such a meter go for these days? I'm sure that some kind of lab with no space issues might have a use for one - this thing looks like it's built to last 50 or 60 years, unless of course someone drops it...
На мелкой плате А84, которая припаяна к другой плате, показалось, что трещина по пайке пошла.
Needs more lead in the base just to make sure.
There is 12n65 TO-220F pakage and power dissipation is 54 Watt. Can it be installed in 150 watt SMPS...?
Please reply sir...
Yes, not the most useful of test gear (outside of a power station perhaps??). But like a lot of fellow enthusiasts salivating over the wonderland array of functionable discrete components and bomb proof hardware🙂
I wonder for what kind of things this was used to measure.
Pěkný udělátko, ale upřímně by mě zajímalo, k čemu to těm Opavským traktorovým strojníkům vůbec bylo 😆
The uA725 (MAA725?) Is a low drift low offset instrumentation amp. They were hard to come by back in the days...
To be honest its a very stupid design using high current over a long time. A more intelligent approach would be to use a storage cap for providing the high current but only for milliseconds , discharging it via a constant current load through the DUT. A simple max detector would hold the measured shunt voltage. Everything would be 28 kilos lighter 😆
Unless the point of the device was to measure resistance under continuous high current, taking into account the resistance change caused by associated heating. (Consider e.g. measuring resistance of a cable that will be used for 80A. You'd then want to actually pass 80A through it.) I'm not sure though if the duration of measurement was sufficient for that.
Nahradíš ten prepínač? Pozrel som po webe a dá sa ešte zohnať; (za predpokladu typu TS 121 11 12/06) / že si to ty, pohľadáš v stashke ;P?
I wonder how much salt it has
No poop capacitors in this one, luckily :-)
30kg .. 😮 wow that's the weight of my E-bike.. 😅
As someone currently suffering from some sort of energy sapping virus (probably the same one), I really felt for you struggling to care about fixing it.
Somehow I knew you would though, you can't keep a good man down!
To by byla docela škoda rozebrat na součástky, přestože to není moc praktický přístroj.
Wonder what specialist use it had.
Is this the fourth time you’ve had Covid?
I guess they used it to measure the resistance of some contacts, switches, terminal blocks, cables, ... Yes, the 4th time.
Must be worth its weight in -gold- , -copper- , iron.
Such a delight these extremely robust industrial grade instruments.
I ❤️ those cable ties.
@@DiodeGoneWild about the creature, sounds funky, because here on Brazil we haven't heard about a single case in ages. I started to thought they finally got it eradicated.
Great methodical troubleshooting; imagine if the device was packed properly and the switch wasn't broken in shipping. I have 6 variacs, one even goes from zero to 240 vac! Keep your videos, including the excellent comments from your cat, coming. By the way, what is your cat's name?
Some copper is definitely there :)
How to donate some dodgy ans safe USB chargers to you? Feel free to reply.
His email address is listed above somewhere.
Bro how to donate item i need to also donate something
Hello, what would you like to donate? Contact me using danyk at centrum dot cz
A small single board vacuum tube computer and big fan from india
Not very useful but beautiful instrument. 😁
One amp power supply & volt meter way to measure low res. Not worth your time.
I seem to get your impression that it is very interesting, but absolutely useless!
66lbs🇺🇸🇺🇸
Burger units 👎