Hi ! first of all thank you sincerely for all your very kind and very valuable video lessons. I am a beginner and slow at learning things but i am finding them very clear and useful. Second i have a question. Sometime i need on the output a 3 terminals arrangement like V-0-V . (For instance in one occasion to power a preamp i needed a transformer outputting 15VAC-0-15VAC) Looking at the video i am not sure how to connect the black, red, orange and yellow wires to achieve a V-0-V output. Maybe connecting red and orange terminals together ? thank you very much again. Kind regards, gino
Good timing - I’m going to post a video in the next couple of days that will show just how to do this. Thank you for posting and please don’t hesitate to ask anything. This is just the subject that many are interested in I hope;)
Great video, I've been trying to learn as much as possible about NTC thermistors so that I can select a properly sized on for a project. You're videos started showing up in the search results and have been really helpful. I also learned a lot about that Siglent scope watching this video. I actually just bought the same scope a couple of weeks ago and am still getting familiar with it.
That's great Chris - thanks for the feedback! I'm just getting started;) Here's a playlist that might help; ua-cam.com/play/PLZ0_iMoMBSskBReu9bhxBDINVRL5Wb78p.html
Hi Eddie, Good information. Looking at your schematic drawing. You have brown connected to neutral and blue connected to live. Also the fuse is in the neutral side, UK colours are brown is live, blue is neutral and green yellow is protective earth. I always reference the dots as the neutral line. Adam
Thanks for that info. I did do some research and it was difficult to find a standard, but I did find a drawing depicting what you described. Thank you!
@@KissAnalog Glad to help ! By the way that transformer costs £30 shipped in the UK The UK colour code, was standardised with Europe a number of years ago Red used to be L1 ( brown as flex to a plug ) Yellow used to be L2 Blue Used to be L3 Black used to be Neutral (blue as flex to a plug) Green/yellow stayed protective earth Adam
@@adaml52 It is fairly strange how many "standards" there are, so many in fact that I think it gives the word "standard" a whole new meaning, like standard = once. I do not think that there are two countrys in Europe that uses the same standard, I can't find any, even when these countrys share power. And even worse is that each country also do use several standards, depending on age, application and "standard". I.e. in Denmark we use R,S,T, Null and ground + L1, L2, L3, Null and ground, each with there "standard" color codes. And don't get me started with plugs!! :-)
@@friedmule5403 The UK wiring colour codes were "harmonised" with Europe a few years ago. Brown, Black, grey are now the three phase conductor colours with blue being neutral. Where black used to be neutral !. My house wiring still has red and black cabling for the single phase conductors. Flex cabling for has not changed, brown,blue,green \ yellow. Do your single phase plugs have an integral fuse ? 😀
@@adaml52 Yes there are some sort of standard now, but in most homes, you'll find 3-4 standards, and even so, you do not have standard in all places, Sweden have a standard, England have a standard and so on. Red leads is ancient in Denmark, but yes you'll still find it. And even that EU have made a try in standards, I do not think that you can find two countrys in Europe that do use the entire same system.:-)
That Oscilloscope display the difference between current in rush peak with and without a thermistor was worth 1000 words that was very clear now I have a visual and I’ll try to repeat your experiment with my transformers and my test equipment that I’m learning how to use. 👍
I'm rebuilding a powered subwoofer but stick, seeing this video gave me insightful information. I have a toroidal transformer that the system came with but as far as a power, stuck. The fuse rated on the label says T1A/250v? But very helpful thanks
Thanks Gavin! If you want to give more info, I'll try to help. It took me awhile to get to this as I am having a hard time keeping up with comments, so I start with subscribers then go down the list;) This looks like a slow blow 1 Amp rated for 250 VAC.
I think the scope was showing 1.60 Amps max for the purple wave, but it was looking for a positive wave. The ch2 was set at 20 Amps/div. But current peaks over 100 Amps is not surprising. Thanks for the feedback!
Great video. Could you please tell me in what series are you talking about VA W. What you started to explain at 15:52. As I didn't catch it at next series. Thank you.
Thanks for the video and the description: I do have one question; I noticed that the schematic shows the switch, fuse and thermistor all on the hot wire, but when wired up, the thermistor is on the neutral side by itself. Does it matter, or should they all be on the host side?
I like those Wago connectors. Just started using them in house wiring, especially when connecting stranded to solid wires, which doesn't work very well with wire nuts.
Great connectors - I just found them on Amazon, and really like how great they work. That’s another great feature, the ability to connect different kinds of wire - thanks for that insight!
I took a job in automation about 2 years ago and was awestruck by those wago connectors when I discovered them on a job site. I now keep a tupperware of both styles in 3 & 5 terminal arrangements on the workbench. They are amazing. What's really great about them, is if you want to connect your meter to check what's going on at a junction, you can just stick your meter lead into the wago connector and clamp down. Now you don't have to hold your meter lead on the connection.
If you are asking why the toroid is better than the E core, then it is mostly due to the shielding affect of the toroid. The toroid shape keeps the magnetic field closed around it where the E core field is much larger and can radiate to other circuits. Thanks for the question, I hope I answered;)
Great video:-) Am I right in that you in last video about inrush current could have used two or more wires to overcome the maximum of 65 amp on your clamp? I mean have used two wires mut only clamped around one of them to get maybe 42 amp = 84 in total inrush? You talk about the Toroid transformer, but I have heard that O-core has less flux and are better in about all and the R-core is even better still?
Maybe I’ll do a quick video showing how to use two wires to help get around the current limitation of the 65 Amp probe. The toroidal core is one of the best to limit coupling with stray magnetic fields, but there are others that offer good shielding, but there are trade offs. A pot core is well shielded but has very little room for exit wires.
@@KissAnalog That would be fantastic!! I think that it may be useful when ever measuring current, inrush or otherwise. :-) The R-core is often talked about as if they remove most of the problem, while keeping the advantages?
@@KissAnalog No problem at all, often do I also not get notifications when you have uploaded a video. So often do I also bench watching your videos. :-)
Kiss Analog , that’s where I’m not too smart, I bought 3 closed loop stepper drivers that power 3 1700 oz in stepper motors. The drivers each take 60volts ac this is all I’m using for this I’m in the US and am powering all this with a toroidal transformer that says it’s 220volts in and 60volts out. I get a in rush of current and just want to get a current limiter to keep the breaker from tripping. Is there a way I can measure what your asking for?
My 25V caps in Firstwatt F5 amplifier has started to swell, even with the thermistor. I have had a few (slow) fuses blown, so I am going to upgrade the protection to something more sofisticated than a thermistor. I noticed a buzzing sound in the speakers after a few months, but continued to use it for five years, with $2000 speaker drivers, no less. It could be because I turned on-off-on to quickly with a warm thermistor that never got the time to cool down. The buzzing sound could also be because of the rats nest of cables I have in there. Or that I biased it the amplifier way too hot. I can hold my finger on the heatsink for 1 second but not more, and I should have biased it so that I can touch the heatsinks without burning my hand. So with all that heat the mosfets might be slightly damaged. Anyway, looking for inspiration to build a much better PSU now. I read that those thermistors are live and can actually shock you, and should be fastened properly when in use. A logical solution would be to shrink tube the thermistors, but that is not a good idea because they need to cool down so you don't wear out your caps and other components with that 70 amps. Really cool of you to show us why a thermistor (or better) is necessary. I always thought I had an idea of what happens, but in this video I can actually see it happening.
Arne McPuckerButt Hey Arne - great to hear from you! Doesn’t that amplifier have 25 VDC rails? So the capacitors should be rated for 50 VDC. The line voltage an swell and the transformer might have been rated for 115 Vac instead of 120 Vac, so the voltage at the rails can be higher than the rating. Also, the transformer has a voltage regulation which at light load can let the voltage rise. Voltage near the rating and high temps can cause this swelling. And if the ripple current rating of the capacitor isn’t high enough - this can cause internal heating and swell the capacitors. The inrush is less likely to be the issue. The buzzing can be do to the capacitors starting to fail and causing a high voltage ripple. I’d be interested in the make and model of your capacitors.
@@KissAnalog It was some cheap Panasonic 25V caps. The designer Nelson Pass still uses 15000 uf, 25V caps in his newer model Firstwatt F7, but here he uses four more caps, totalling at twelve 15000uf 25V caps. It looks something like this: forum.polkaudio.com/discussion/173282/and-the-quest-continues When I built the F5 I followed this build guide: guides.diyaudio.com/Guide/Firstwatt+F5+amplifier+v3/6 . The design of the power supply has not changed much over the years. Also, in Norway we have 230V.
@@KissAnalog I have started looking at your videos to see if you have a better idea for a power supply than the amplifier guru Nelson Pass. Using my own version of his designs has been a bit hit and miss, but that could be my fault completely. If you want you can look at the link to the guide that I sent you and see if you would do anything differently.
The toroid isn't solid actually it's made from just one thin laminated plate wound very tight into a coil which is needed for the eddy currents, this type is only used for 50 and 60 Hz toroid transformers
Thanks for the correction. I'm so used to doing high frequency switching power supplies I probably said something without thinking;) That probably happens too often;)
Yes thank you! Your wires do not care about AC but some like color coding to know which (Neutral) is connected to the ground at the service entrance. I’ve seen electricians who swear by Wegos…so you don’t like them? Do you prefer wire nuts?
Hi ! first of all thank you sincerely for all your very kind and very valuable video lessons. I am a beginner and slow at learning things but i am finding them very clear and useful. Second i have a question. Sometime i need on the output a 3 terminals arrangement like V-0-V . (For instance in one occasion to power a preamp i needed a transformer outputting 15VAC-0-15VAC) Looking at the video i am not sure how to connect the black, red, orange and yellow wires to achieve a V-0-V output. Maybe connecting red and orange terminals together ? thank you very much again. Kind regards, gino
Good timing - I’m going to post a video in the next couple of days that will show just how to do this. Thank you for posting and please don’t hesitate to ask anything. This is just the subject that many are interested in I hope;)
@@KissAnalog hi thanks a lot i subscribed to this very nice channel regards gino
gino I am so happy to have you
Man I really find value in your videos, thank you for the hard work you put into them.
Thanks so much! I appreciate you!
You convinced me to buy thermistors. I have looked at switch bounce before with dc, usually lasts about 8 ms.
Thanks - and yes - one cycle is about 8ms so that is about right;)
Great Eddie! Excellent showing how the current spikes with and without the thermistor.
Thanks Steve 👍
Great video, I've been trying to learn as much as possible about NTC thermistors so that I can select a properly sized on for a project. You're videos started showing up in the search results and have been really helpful. I also learned a lot about that Siglent scope watching this video. I actually just bought the same scope a couple of weeks ago and am still getting familiar with it.
That's great Chris - thanks for the feedback! I'm just getting started;) Here's a playlist that might help; ua-cam.com/play/PLZ0_iMoMBSskBReu9bhxBDINVRL5Wb78p.html
Hi Eddie, Good information.
Looking at your schematic drawing.
You have brown connected to neutral and blue connected to live.
Also the fuse is in the neutral side, UK colours are brown is live, blue is neutral and green yellow is protective earth.
I always reference the dots as the neutral line.
Adam
Thanks for that info. I did do some research and it was difficult to find a standard, but I did find a drawing depicting what you described. Thank you!
@@KissAnalog
Glad to help !
By the way that transformer costs £30 shipped in the UK
The UK colour code, was standardised with Europe a number of years ago
Red used to be L1 ( brown as flex to a plug )
Yellow used to be L2
Blue Used to be L3
Black used to be Neutral (blue as flex to a plug)
Green/yellow stayed protective earth
Adam
@@adaml52 It is fairly strange how many "standards" there are, so many in fact that I think it gives the word "standard" a whole new meaning, like standard = once. I do not think that there are two countrys in Europe that uses the same standard, I can't find any, even when these countrys share power. And even worse is that each country also do use several standards, depending on age, application and "standard".
I.e. in Denmark we use R,S,T, Null and ground + L1, L2, L3, Null and ground, each with there "standard" color codes. And don't get me started with plugs!! :-)
@@friedmule5403
The UK wiring colour codes were "harmonised" with Europe a few years ago.
Brown, Black, grey are now the three phase conductor colours with blue being neutral.
Where black used to be neutral !.
My house wiring still has red and black cabling for the single phase conductors.
Flex cabling for has not changed, brown,blue,green \ yellow.
Do your single phase plugs have an integral fuse ?
😀
@@adaml52 Yes there are some sort of standard now, but in most homes, you'll find 3-4 standards, and even so, you do not have standard in all places, Sweden have a standard, England have a standard and so on. Red leads is ancient in Denmark, but yes you'll still find it.
And even that EU have made a try in standards, I do not think that you can find two countrys in Europe that do use the entire same system.:-)
That Oscilloscope display the difference between current in rush peak with and without a thermistor was worth 1000 words that was very clear now I have a visual and I’ll try to repeat your experiment with my transformers and my test equipment that I’m learning how to use. 👍
t lech Thanks - good luck and have fun!
I'm rebuilding a powered subwoofer but stick, seeing this video gave me insightful information. I have a toroidal transformer that the system came with but as far as a power, stuck. The fuse rated on the label says T1A/250v? But very helpful thanks
Thanks Gavin! If you want to give more info, I'll try to help. It took me awhile to get to this as I am having a hard time keeping up with comments, so I start with subscribers then go down the list;) This looks like a slow blow 1 Amp rated for 250 VAC.
Hi EDDIE, thank you for the information, Good video.
Glad you enjoyed it. Thank you.
Thanks good video. Very informative. I wasn’t sure how to wire one of these up now I do.
Thanks Tron!
Awesome. Learned much. You took out the thermistor and said the in-rush current was 70 amps. It looked like the scope said 150A? Peak to Peak?
I think the scope was showing 1.60 Amps max for the purple wave, but it was looking for a positive wave. The ch2 was set at 20 Amps/div. But current peaks over 100 Amps is not surprising. Thanks for the feedback!
Great video.
Could you please tell me in what series are you talking about VA W. What you started to explain at 15:52.
As I didn't catch it at next series.
Thank you.
I'm sorry I missed this comment. Are you a subscriber? Let me know if you need help with this.
Thanks for the video and the description: I do have one question; I noticed that the schematic shows the switch, fuse and thermistor all on the hot wire, but when wired up, the thermistor is on the neutral side by itself. Does it matter, or should they all be on the host side?
I should have watched for a few more seconds, you cleared it up. Thanks again not just for the video, but for the entire series.
Thanks so much for your comments and support!!!
I like those Wago connectors. Just started using them in house wiring, especially when connecting stranded to solid wires, which doesn't work very well with wire nuts.
Great connectors - I just found them on Amazon, and really like how great they work. That’s another great feature, the ability to connect different kinds of wire - thanks for that insight!
I took a job in automation about 2 years ago and was awestruck by those wago connectors when I discovered them on a job site. I now keep a tupperware of both styles in 3 & 5 terminal arrangements on the workbench. They are amazing. What's really great about them, is if you want to connect your meter to check what's going on at a junction, you can just stick your meter lead into the wago connector and clamp down. Now you don't have to hold your meter lead on the connection.
Chris Storm I’m so happy that I found them;)
Hi eddie.I have 1000Va torodial for Tda8954.Does it need some y or x capacitors on primary side?
Thank you! Yes - I think that is always a great idea. I'll do a video shortly on how to design a basic and useful EMI filter;)
Hey, why this power supplies are better than a conventional one and can this improve a video source?
If you are asking why the toroid is better than the E core, then it is mostly due to the shielding affect of the toroid. The toroid shape keeps the magnetic field closed around it where the E core field is much larger and can radiate to other circuits. Thanks for the question, I hope I answered;)
@@KissAnalog hey, thank you so much for the explanation
WOULD IT BE A GOOD IDEA TO USE A 60HZ LINE FILTER BETWEEN THE PLUG AND,TRANSFORMER?
Yes - that’s a great observation!
Great video:-)
Am I right in that you in last video about inrush current could have used two or more wires to overcome the maximum of 65 amp on your clamp? I mean have used two wires mut only clamped around one of them to get maybe 42 amp = 84 in total inrush?
You talk about the Toroid transformer, but I have heard that O-core has less flux and are better in about all and the R-core is even better still?
Maybe I’ll do a quick video showing how to use two wires to help get around the current limitation of the 65 Amp probe. The toroidal core is one of the best to limit coupling with stray magnetic fields, but there are others that offer good shielding, but there are trade offs. A pot core is well shielded but has very little room for exit wires.
@@KissAnalog That would be fantastic!! I think that it may be useful when ever measuring current, inrush or otherwise. :-)
The R-core is often talked about as if they remove most of the problem, while keeping the advantages?
Fried Mule I’m just now minding comments that were posted a long time ago. I’m sorry - I often don’t get notified of comments...
@@KissAnalog No problem at all, often do I also not get notifications when you have uploaded a video. So often do I also bench watching your videos. :-)
If I have a 220v ac in 60v ac out what current limiter would I need like the one you show hooked up?
trialnterror Great question! What is the power input? What is connected to the load?
Kiss Analog , that’s where I’m not too smart, I bought 3 closed loop stepper drivers that power 3 1700 oz in stepper motors. The drivers each take 60volts ac this is all I’m using for this I’m in the US and am powering all this with a toroidal transformer that says it’s 220volts in and 60volts out. I get a in rush of current and just want to get a current limiter to keep the breaker from tripping. Is there a way I can measure what your asking for?
trialnterror What is the rating of your circuit breaker?
Hi there,
How do you connect channel 2 to measure the current?
My 25V caps in Firstwatt F5 amplifier has started to swell, even with the thermistor. I have had a few (slow) fuses blown, so I am going to upgrade the protection to something more sofisticated than a thermistor. I noticed a buzzing sound in the speakers after a few months, but continued to use it for five years, with $2000 speaker drivers, no less. It could be because I turned on-off-on to quickly with a warm thermistor that never got the time to cool down. The buzzing sound could also be because of the rats nest of cables I have in there. Or that I biased it the amplifier way too hot. I can hold my finger on the heatsink for 1 second but not more, and I should have biased it so that I can touch the heatsinks without burning my hand. So with all that heat the mosfets might be slightly damaged. Anyway, looking for inspiration to build a much better PSU now.
I read that those thermistors are live and can actually shock you, and should be fastened properly when in use. A logical solution would be to shrink tube the thermistors, but that is not a good idea because they need to cool down so you don't wear out your caps and other components with that 70 amps.
Really cool of you to show us why a thermistor (or better) is necessary. I always thought I had an idea of what happens, but in this video I can actually see it happening.
Arne McPuckerButt Hey Arne - great to hear from you! Doesn’t that amplifier have 25 VDC rails? So the capacitors should be rated for 50 VDC. The line voltage an swell and the transformer might have been rated for 115 Vac instead of 120 Vac, so the voltage at the rails can be higher than the rating. Also, the transformer has a voltage regulation which at light load can let the voltage rise. Voltage near the rating and high temps can cause this swelling. And if the ripple current rating of the capacitor isn’t high enough - this can cause internal heating and swell the capacitors. The inrush is less likely to be the issue. The buzzing can be do to the capacitors starting to fail and causing a high voltage ripple. I’d be interested in the make and model of your capacitors.
@@KissAnalog It was some cheap Panasonic 25V caps. The designer Nelson Pass still uses 15000 uf, 25V caps in his newer model Firstwatt F7, but here he uses four more caps, totalling at twelve 15000uf 25V caps. It looks something like this: forum.polkaudio.com/discussion/173282/and-the-quest-continues
When I built the F5 I followed this build guide: guides.diyaudio.com/Guide/Firstwatt+F5+amplifier+v3/6 . The design of the power supply has not changed much over the years.
Also, in Norway we have 230V.
@@KissAnalog I have started looking at your videos to see if you have a better idea for a power supply than the amplifier guru Nelson Pass. Using my own version of his designs has been a bit hit and miss, but that could be my fault completely. If you want you can look at the link to the guide that I sent you and see if you would do anything differently.
Arne McPuckerButt Thank you! I’m sorry I just found these comments. How is it going? Did you get these Amps built?
The toroid isn't solid actually it's made from just one thin laminated plate wound very tight into a coil which is needed for the eddy currents, this type is only used for 50 and 60 Hz toroid transformers
Thanks for the correction. I'm so used to doing high frequency switching power supplies I probably said something without thinking;) That probably happens too often;)
What size thermistor would be needed for a 230 volts torroid transformer?
Great question! It isn't really a function of the voltage but of the current. So, it depends on the wattage and size of capacitors.
12:58 min, Is that meter true R.M.S. ?
The Tektronix DMM157 is averaging sensing RMS, so no True RMS.
Safety tip: Dont wear metal jewelry when building power supplies. And that tape looks very dodgy.
You are right - LOL! I’ve been very lucky but I did have a close call once;)
First AC does not matter which way the wires are connected as far as polarity and Wego's are garbage A fire waiting to happrn
Yes thank you! Your wires do not care about AC but some like color coding to know which (Neutral) is connected to the ground at the service entrance. I’ve seen electricians who swear by Wegos…so you don’t like them? Do you prefer wire nuts?