Interesting. I was rewinding these type transformers in 1995-2000. Initially it took 7-8 hours to rewind manually later on I managed to make a small devise by using parts of an old photocopier and reduced to 30 minutes. It is very efficient.
The R just stands for the round shape of the profile. Often the core is grain-oriented silicon steel with no air-gap. The leakage flux in an R-Core Transformer is about 1/10th that of conventional EI or UI transformers.
this is a very old video but I’ve just seen it and it’s really informative. Wouldn’t the capacitor give you a very choppy sine wave on the input coil as it cuts the input above a certain voltage? I take it you’ll need an output capacitor to buffer for these gaps?
Has always, a very interesting video. Have you checked any of the surplus electronic sites to see if the carry this transformer. I am looking forward to your next video. Thank you for sharing.
electronicsNmore Thank you for the reply. Where I live I would never find one. Do they have a part number or name. I would like to find some. Thank you again.
R core Transformers are used in Technics Hifi Equipment. The other Transformer is the TUI Core Traqnsformer from Technics and the standard Transformers.
electronicsNmore Ok,I was just wondering,...I have one of those transformer calculating programs I look at sometimes, but it is pretty simplified. I just saw you in a comment section of a video and I have started to search out people from comment sections to locate the people that I think probably are the most experienced with particular subjects. Thats ok, I know how it is, I myself have some old RUclips videos, but I would have the same problem to try and remember what I did.
3:23 lol that doesn’t seem easy to me, more like tedious. I designed a few vacuum tube products using R core some years back. I was able to get noise figures around -95dB on a high gain pentode circuit. Seems unbelievable until you hear it. I won’t use anything else for power.
I wound the spools in a couple minutes using a cordless drill with a thick, wide rubber band wrapped around the chuck. You place the chuck against the spool and the wire fills up the spool quickly. Thanks for watching!
So it's basically a square toroidal transformer, definetly a smart idea, and makes winding the coils very easy since you can just spin the spools around.
electronicsNmore I have a accident today,my fingers slightly burned when im testing my carbon short-arc lamp.Now room smells like burned fingers:D,sad:(
You might be able to use electrical grade iron wire to actually make one from scratch, or would the hysteresis loss be too much at mains frequencies (50-60Hz)? (I've mainly dealt with that kind of core on telephone gear at AF, 200 to 4000Hz ish)
This R-Core transformer was primarily designed as an audio transformer, but it does seem to work fine as a power transformer. I don't see why you could not take 1/32" or 1/16" iron wire and wind up a nice neat tight bundle to make a core.
If your transformer gets hot when there's no load on it (presumably due to the resonant effects ov your L.C. hookup) you might want to consider a shunt regulator topology for your PSU. That way you'll always have a load on it.
electronicsNmore Yeah I just thought that was an easy way you could make sure that you always have a load on it. Shut regs do have some advantages, but usually they are not considered because ov the bleed current. However in this case that is also an advantage, so that could be a good approach. :)
Hi There! No. The transformer was removed from a 60HZ/120V device. You can use 50HZ transformers with no problem on 60HZ, but not the other way around. Thanks For Watching! Be sure to share and rate Thumbs up.
Hi there. Solid cores aren't used because they're inefficient. Laminated iron cores are used to reduce "Eddy Currents". Be sure to share my channel with many others, rate thumbs up, look over my extensive video playlists for other great videos of interest to you, and subscribe. Thanks for watching!
Measure the resistance of each winding. Thanks for watching! Be sure to check out my extensive video playlists for other great videos of interest to you, rate thumbs up, and share with others.
Very nice transformer. The first time I saw one of these oddities, it was in a half million dollar piece of equipment.
Interesting.
I was rewinding these type transformers in 1995-2000.
Initially it took 7-8 hours to rewind manually later on I managed to make a small devise by using parts of an old photocopier and reduced to 30 minutes. It is very efficient.
It's a very unique transformer design.
The R just stands for the round shape of the profile. Often the core is grain-oriented silicon steel with no air-gap.
The leakage flux in an R-Core Transformer is about 1/10th that of conventional EI or UI transformers.
this is a very old video but I’ve just seen it and it’s really informative. Wouldn’t the capacitor give you a very choppy sine wave on the input coil as it cuts the input above a certain voltage? I take it you’ll need an output capacitor to buffer for these gaps?
The transformer reminds me of a iron ferrite toroid transformer that I see used in circuits like the joule thief... Nice find :)
Has always, a very interesting video. Have you checked any of the surplus electronic sites to see if the carry this transformer. I am looking forward to your next video. Thank you for sharing.
I'm sure if I searched, I could find some surplus ones being sold, but there is nothing like the ones for free!
Thanks For Watching
electronicsNmore Thank you for the reply. Where I live I would never find one. Do they have a part number or name. I would like to find some. Thank you again.
Just look up R-Core transformer.
R core Transformers are used in Technics Hifi Equipment. The other Transformer is the TUI Core Traqnsformer from Technics and the standard Transformers.
How many windings do you think should have been on the primary side?
Hi John. It has been a while since I watched this video, so I would have to watch it again in order to answer your question.
Thanks
electronicsNmore Ok,I was just wondering,...I have one of those transformer calculating programs I look at sometimes, but it is pretty simplified. I just saw you in a comment section of a video and I have started to search out people from comment sections to locate the people that I think probably are the most experienced with particular subjects. Thats ok, I know how it is, I myself have some old RUclips videos, but I would have the same problem to try and remember what I did.
very, ver good.
can you send diagram please?
3:23 lol that doesn’t seem easy to me, more like tedious. I designed a few vacuum tube products using R core some years back. I was able to get noise figures around -95dB on a high gain pentode circuit. Seems unbelievable until you hear it. I won’t use anything else for power.
I wound the spools in a couple minutes using a cordless drill with a thick, wide rubber band wrapped around the chuck. You place the chuck against the spool and the wire fills up the spool quickly. Thanks for watching!
electronicsNmore hmm, that’s clever. I wind my own EI lam transformers; I’ll see if I can figure out a workaround like that for my winding machine.
good video
Thanks! Be sure to check out my extensive video playlists, rate thumbs up, subscribe, and share my channel with others.
So it's basically a square toroidal transformer, definetly a smart idea, and makes winding the coils very easy since you can just spin the spools around.
Yes, very easy to wind the spools. :-)
Cool and interesting!
Many cool and interesting videos on this channel. Be sure to check them out, rate thumbs up, subscribe, and share. Thanks
electronicsNmore Already subscribed you,since 2014:)
Alper Gökcek
Nice. :-)
electronicsNmore I have a accident today,my fingers slightly burned when im testing my carbon short-arc lamp.Now room smells like burned fingers:D,sad:(
Alper Gökcek
Burned skin does not smell as bad as burned hair. :-)
You might be able to use electrical grade iron wire to actually make one from scratch, or would the hysteresis loss be too much at mains frequencies (50-60Hz)? (I've mainly dealt with that kind of core on telephone gear at AF, 200 to 4000Hz ish)
This R-Core transformer was primarily designed as an audio transformer, but it does seem to work fine as a power transformer. I don't see why you could not take 1/32" or 1/16" iron wire and wind up a nice neat tight bundle to make a core.
If your transformer gets hot when there's no load on it (presumably due to the resonant effects ov your L.C. hookup) you might want to consider a shunt regulator topology for your PSU. That way you'll always have a load on it.
It gets warm/very warm. The capacitor prevents it from getting hot. Your right about the shunt regulator though. :-)
electronicsNmore Yeah I just thought that was an easy way you could make sure that you always have a load on it. Shut regs do have some advantages, but usually they are not considered because ov the bleed current. However in this case that is also an advantage, so that could be a good approach. :)
Is it possible that it was getting hot because it was designed for 50Hz mains and it was being tried on a 60Hz mains?
Hi There!
No. The transformer was removed from a 60HZ/120V device. You can use 50HZ transformers with no problem on 60HZ, but not the other way around.
Thanks For Watching! Be sure to share and rate Thumbs up.
Hmmm maybe a link from a very big chain can be used for the core?
Anyone tried that?
Hi there. Solid cores aren't used because they're inefficient. Laminated iron cores are used to reduce "Eddy Currents". Be sure to share my channel with many others, rate thumbs up, look over my extensive video playlists for other great videos of interest to you, and subscribe. Thanks for watching!
@@electronicsNmore Yes ofcourse youre right! LoL! My bad.
Keep making great videos. =)
I'll share them.
Next time use a ballast rather a Capacitor.
Trust me.
Use like a 40W if you need a 20V * 2A power. Use higher if you need. Use a MAGNETIC BALLAST.
It’s getting hot because Japanese line voltage is only 100V and you are using on American line voltage of 120v.
No, the device it was pulled from was designed for 120V / 60HZ. The issue was my windings.
How can test r core transformer??
It's ok not??
Measure the resistance of each winding. Thanks for watching! Be sure to check out my extensive video playlists for other great videos of interest to you, rate thumbs up, and share with others.
Most probably this is a speaker / PA line transformer rather than a power one...
Yes, it is used in audio amplifiers, but does work for power also.
Its an output trans
Audio Output
I found these in ebay
ZERO-ZONE-30VA-R-core-Transformer-115-230V-to-0-9V-0-9V-0-15V-0-15V-L159-10