I suppose u could use two LEDs (albeit installed in the radio). Green LED ON means all is OK. Red LED ON means chassis is LIVE. No LED on means GND is not connected. But if you are color blind it may be a problem.
You also have a great sense of humor. Bless you. By the way, on the US plug, you got it right, the big prong is Neutral indeed. Some old houses however, might still have the old outlets where both prongs are the same side. Of course they have to be changed, or had to be changed, since all appliances going back to the 70s, have the polarized cords. some even have the ground pin. Now as to the 220/230 volts, i was in Greece when i was a kid and they have/had the same plugs there as what you are using. I also have a couple of Grundigs, that i love dearly with tubes. One has dual voltage input, while the 2nd is 110v only. They both date back to the 60s. Unlike you, i can't fix them, though i did have them repaired here, some time back. BUT, i love watching videos as informative as yours... Stay well and thank you again.
M! I usually enjoy your videos very much, and this one is no exception to that. Well thought out, informative, educational, practical, useful, helpful, entertaining, thought provoking...a darn good video!!! You are right about the plugs in the United States of America...at least to a point. There is only one way that the plug will plug into the wall socket...however, unfortunately there are some places where whoever wired the house did not follow the code. In those cases, you can still get shocked. A device like yours could be useful here too. One thing I would have done differently though, is that I would have mounted the LED on the end where the power cord enters the plug. That way, it doesn't matter which way you plug in the cord, you could see the light easier. Still an excellent idea and well done. On the subject of wiring, I once lived in a house in Georgia where the Dimwitt that wired it decided that AC is NOT polarized, and therefore it "didn't matter" which wire went where. Therefore he wired the house with black and white wires connected together in many places. I discovered it when I opened the refrigerator and the kitchen light went off. Closed the door and it came back on! Again, really enjoyed the video!!!
Thanks for that. As usual, a prototype always need a version 2: I had the same thought about the positioning of the led when I first used it. Next time 😊 I think the problem with doing this in the US is the size of the plugs - much smaller, if I’m not mistaken. Wherever you go, dimwits will always leave their mark.
YES, that is one very important quality, or talent, that every tech related UA-camr must have. I follow more than 30 tech channels, some even with more than a million subscribers, only 2 or 3 of them can manage this.
I recall building a AC voltage tester in electronics shop using a ne-2 neon bulb and a resistor, no bridge rectifier needed. It draws micro amps of current and lasts a long time. Thank you for this safety tip.
This is an elegant solution. In France they have the same plug but with an additional socket for ground. They wall socket has the same two connections plus a grounding pin which makes it impossible to reverse the connection. German plugs and sockets don't have the grounding pin arrangement. I'm definitely going to use this system.
The problem is that Czechia uses the same plug but with the opposite polarity. In Poland the polarity can be either way as I think was earlier in France. The pin is not intended to enforce polarity. Schuko at least allows you the choice to reverse.
Great idea and nice implementation. Another option would be to use a green LED wired to illuminate when the plug is correctly inserted. That way, if/when the LED fails, or an internal connection breaks, you know there is *some* problem: either plugged in backwards, or the plug circuit itself has failed. (Sorry - before retirement I was an embedded controls engineer for commercial equipment, meaning my first thoughts are always "What if it fails? What if they make a smarter idiot? What if ..."). But, the red=wrong is good, too. Red is the standard warning color, and with your method, you get a really clear indication that the plug is in wrong. Pay your money and take your choice, I suppose. Another advantage with your method is no extra leakage current when the plug is in correctly.
I agree with the “what if it fails” outlook. I tend to do that myself which is why I never seem to stop making changes to my designs. However, in this case, there are so many options that I had to force myself to stop at the one that did the job.
Hmmm. Interesting. I tend to steer away from hot chassis radios but have ended up with one and have been mulling over what kind of warning system I could put in place. It got me thinking. I have a feeling that this could be done with one of your LED converter boards. It would only catch the half wave of the cycle to iluminate the LED but I think it would give the same result (using a 220k resistor, obvioulsy!). The SMD board version is tiny so takes up very little space.
The plug version that I did works very well. Have a look at that video. I used a miniature bridge rectifier in it, and everything fit nicely on the plug.
This only doesn't work when you plug it into a non-earthed socket. I don't know about Portugal, but in The Netherlands (where we have the very same type of plug), many homes still have non-earthed sockets in most rooms. The earthed plugs do fit in there, but with the earth contact disconnected, the LED won't light.
Not only in NL also in BE and GER the earth ground connection can be missing. Or as found often after rennovations, the tabs providing earth ground connection have been covered in wall paint. To inform of such a situation, the dangers involved and this indicator staying dark thus falsely indicating a proper orientation, there is an easy remedy; inside the plug place a 270-330k resistor from Live to earth ground. If earth ground is floating the LED will light either which way the plug is inserted. Also to make things easier and avoid the risk of placing big components in a small environment that has potentially 3kW of electrical power available befor the house wiring breaker trips, I would have used a single diode instead of a bridge rectifier to save on space. Or alternatively place a 1N4148 antiparallel to the LED. Also there are LED available with two (!) antiparallel(!) chips in one case, so the LED can be used on AC without additional rectification. Most prominent are the bi color types where in one direction they light red and green the other. Subjected to AC thus u get an orangy color.
This modification is to allow the use in an earthed socket. You do not need it with non-earthed sockets. With non-earthed sockets the safety is based on the fact that there is no earth nearby. This is not ideal especially nowadays though as there are so many different equipment so it is hard to keep earth out. Remember the old rule: if it fits, it is OK.
Older plus in the US are not polarized. But even polarized plugs can still be plugged in either way in most outlets. So your caution still applys to a hot chassis
Hi.Good idea, I appreciate it. However, here in Portugal (where I live too), a good portion of homes are very old and do not have ground line instaled. The outlets are flat without ground terminal or schuck standart outlet without any connection at ground terminal. Why not a single connection by one led in series with a resistor between Line and Neutral ? The orientation for the plug will keeped with no ground dependance, and less components inside the plug. What is your opinion about ? Many thanks in advance and keep your good restorations.
Hi again. My apologise, I made a mistake. Thinking twice, my idea will not work as we are dealing with AC and the led will always light up. It is necessary a third point (ground) to be the reference between L and N. Never the less, my concern still on, lots of homes here in PT did not have ground line and the problem still open.
Correct. Didn’t think it though completely. As for it’s use however, this is not a comercial design at all. It’s for my own use and therefore suits the purpose well. I recall my grandparents’ house in the country having no ground at all, and tingles (if not outright shocks) were quite common. They had a rather strong respect for the wiring in the house 😊
In principle if you have ungrounded sockets you should not have ground potential nearby so you could use the original plug. In principle as modern homes are far more complex with antenna and data cables that can provide earth and there were compromises in the old rules. There is no way to tell from an ungrounded outlet using the contacts the outlet gives which is hot an which neutral. You can do it one grounded outlet as the neutral and groudn are connected together or both are separately grounded. Note that while the modification is reasonably safe, it is illegal at least in Finland. The best is to determine in which position the chassis is neutral and mark that on the plug. As you use the same socket you have no problem.
In Poland, we have an even bigger mess with it. There are sockets (old type C sockets) without grounding, non-polarized, and sockets with a male earth plug (type F), so theoretically they cannot be inserted the other way round. However, there is no law regulation, which side should be the live and which side should be neutral. It is described only as good practice among electricians to place the phase in the right pin.
Great video. Do you actually need the rectifier? I would have thought with sufficient resistance it would not damage the LED and work without one just lighting on the half wave.
It would, but then you’d have the full reverse voltage across the led on the negative half-cycle, and that would not be good for the led. you could simply connect a diode in reverse across the led and that would work fine.
The plug has a ground connection to the wall but you don’t take a 3rd wire to the chassis? In the US one plug pin is fatter than the other so we don’t have the option to do the flip. I have seen wall sockets that were reversed. So as a general rule I put three wires to the chassis. But your solution allows for only two. I’ll keep it in mind. This reminds me of my balanced power isolation transformer, where both pins go live after the secondary (60v each here in the USA)and the ground is in the middle. I use this for my ‘special tube audio’ system. An old friend who worked for Raytheon for 40 years and did life support medical equipment for them, he gave me the transformer and explained how to configure it for best and quiet operation and he swore it would be the safest setup too. Everything with the straightest connection to ground. The balanced power makes a big difference to the sound and all components are dead quiet.
This radio appears to have a double-pole on-off switch, which is good. There ere some radios where the on-off switch disconnects the wire from mains to chassis only. This means: if the radio is on, the chassis is at neutral (good), but if the radio is off, the chassis is hot again (not good). Does the pickup input have capacitors isolating both lines from the circuit? So is there also a cap isolating the pickup ground input from the chassis? Most hot chassis radios (if they have a pickup input) have this, but not all. If the radio is intact and the back plate is on, those radios are supposed to have no exposed metal parts that are connected to the chassis. That's the theory at least. We used to consider them safe, way back when.
Great idea 💡 . But wouldn’t it also work without the rectifier ? The LED will block on reverse polarization. Or will it blow when 230v are attached in reverse ? Just asking....
This is something that has been bothering me for some time, I am in the US and we do have polarized plugs. I have older equipment such as Yamaha stereos from the 70s and I never really understood why something had to be one way or the other. I am currently restoring a friends Sansui 551 reciever from 1975. it has an un-polarized plug. The existing plug and wire are in good shape. so I seem to have 2 options replace the end of the cord or replace the entire cord. I am not the owner so I need to let him make the decision. My preference is to replace the entire cord. in the mean time I just took a piece of painters tape and wrote big and small to the corresponding live and neutral prongs so at least I can choose to plug it in the best way. I plan to update all of my old stuff with polarized plugs that are wired correctly.
We all need to be a little more careful about mains polarity with older equipment. Speaking for myself, I know I get a little careless sometimes, and that can be a problem .
A lot of "vintage" audio gear, has it's line voltage "isolated" by going to a transformer, so, this is usually not a concern. Some antique radios that use a "series strung" tube filament design may have (here's where having and comprehending a schematic is a valuable skill) one side of the line cord, which usually was not polarized, directly connected to, or coupled with a low value capacitor (popularly called the "Death Capacitor") to the chassis, and these would be of concern. Those radios almost always have bakelite plastic or wood cabinets and plastic knobs so you would never touch an energized piece of metal by accident. Using a 2 prong polarized plug, or changing to one, is a good idea in those cases, but you are still at the mercy of the electrician that wired that outlet, and it is best to get a polarity tester and check outlets before use to verify they are wired correctly.
In Australia our plugs are polarized, but my 1960 Schaub Lorenz has a plug with two flat pins so I will need to use an adaptor to suit an Ozzie plug. It could then be plugged in either way. Is this an issue with a radio which has a standard transformer which offers some level of isolation?
Great channel. Congratulations! I love the content! I just thought how this will work in a home that's has IDR protection circuit. Would it be not a problem?
Important topic. But since it‘s really dangerous I would have placed the led to the back, not to the side. And I also would have used a flashing/blinking one.
I had to sleep this over, and this might be a bit picky, but I think there is a minor issue with your design. If I remember correct, the standard of the shelf 1/4W metal film resistor is rated for 250VDC max. 1/2W types usually are rated for 300VDC maximum working voltage. And those values apply for brand resistors. My worries arose by thinking someone may built something similar and using a resistor made of chiniesium... Applying 230VAC, the peak voltage across the resistor is roughly 330VDC and thereby exceeding it's maxium ratings. As this is a sort of of a "safety equipment", I would propose to use two resistors in series. Thereby droping the voltage across the resistors into a safe operating zone. And yes, I know, these times you find the cheapest chiniesium 0603 resistors, rated for 75V at best, as bleeding resistor across capacitors in capacitor dropper circuits in every second LED-Lamp in your household and nobody gives a sh*t...
Good point. I mentioned a 600mW resistor in the video, but the same problem could apply. As the purpose is to swap the plug as soon as you see red, the power dissipation period is actually very short, but voltage flash-over could be a problem in really crappy resistors, as you say.
Nice idea. How about adding a green one across live and earth, this should always be on and would show that the earth was present (which if it isn't would invalidate the red led test). I suppose the only issue could be if that was the "final straw" 1mA that makes the RCD trip :-). [update - in fact, would you just need the live/earth one - i.e. must be lit for radio to be safe?]
Good invention and very simple! But in a good condition radio you should have no easy acess to the chassis during normal operation. ususally there is wax covering the knob screw-holes and the screw is recessed. etc... maybe on some sets if you grab and move the radio with it plugged in you can get a shock, but that can be adressed mechanically (covering exposed screws underneath if they protrude) but usually that is taken care by the radio manufacturer. also there are certain situations were neutral can shock you too, lets say the neutral wire to the grid has a bad connection and you touch it, whatever current wants to flow throught the circuit will flow through you and to earth instead of the neutral, sometimes if you have wet feet etc you can feel a zap in the neutral.Your differential breaker should trip but it often doesnt.... i did a lot of domestic wiring for a company and during that time i took some neutral zaps. happens even more easily when there is lots of current flowing trough the wires for example when an electric heater is on etc etc. if the neutral offers resistance, if there is too much currint going through that wire and you touch it some of it will find a good path to earth trough your body Personally i must have my vintage stuff with vintage plugs, i have a big radio that the wife uses but its a power transformer set, the rest of radios and tvs are only used by me and MORE IMPORTANT on vintage gear, ALWAYS unplug when not in use and never leave them on unatended, those are the golden rules for me. Cheers!
@@electronicsoldandnew on that radio its not 100% safe to use the phono input even if chassis is neutral..well, its better than live but still.....ideal situation would be a small 1:1 coupling transformer maybe???
The flicker - if visible - doesn´t matter, because the plug has to be plugged in so that the LED doesn´t light and we have no permanent flicker; only for alarm. BTW, the antiparallel diode could be a second LED antiparallel and could be mounted on the other side of the plug so that at least one LED is always visible
I was stationed in South Korea for a few years and they have the same plugs and voltage as Portugal. While living off-base, I got shocked once at 230V when I touched my American microwave with one hand and my kitchen faucet with the other. Turned out the step-down transformer that I was using, and which I'd bought in the Base eXchange along with the microwave, was faulty. It had a three-pronged outlet to fit American appliances but the maker had literally pulled the ground receptacle out so only the hot and neutral sockets were present. That was bad enough, and is actually "normal procedure" for Korea, but the fault in this case was present in the transformer windings. The shock hazard didn't go away until I replaced the whole transformer unit. Two tips for my American compatriots: 1. Watch out for those cheapie BX step-down transformers, many of them are death-traps, and 2. for those of you living in the US, you can pick up a cheap outlet tester in any big-box store for about 8 bucks and it will tell you immediately if your three-pronged 120V outlets are wired correctly. Mine was made by Commercial Electric and it was well worth the investment.
@@rossthompson1635 Understand. So was mine. When I returned home from Korea I rewound it and converted it into a 1:1 isolation transformer (115V). It works well enough, but the 14 awg aluminum wire it had originally, and that I used to rewind it, makes it rather inefficient. Fortunately, I only need it to work intermittently until I can build the isolation-dim-bulb-variac device that I'm now collecting parts for.
Just a danger setup... I hope nobody else than you is using that radio! In some old installations in PT we don't have even sockets with earth 😆. If you wanna save and use this nice radio, make it safe, replace the autotransformer!
This sort of circuit should be in every non-polarised plug. We have never had the issue in Australia even with two pin plugs as our Live and Neutral pins are at an angle so it can only go in one way. That said, I have known plugs and even sockets to be wired incorrectly
And which way you would indicate the danger on modern equipment? Toss a coin? This is a very specific modification for very specific application, nothing more.
@@okaro6595 if modern equipment is wired CORRECTLY there would be no issue. Incorrectly wired devices we cannot compensate for, and these would not pass any tests or certification anyway. This plug modification is perfect for polarisation, which is all it was ever designed for
@@EsotericArctos Yes, it is a good option for this problem. It is a good hobbyist solution, not for a layman as it still requires activity form the user and it also is not to the code. Polarization is really issue only on lamps and it would make more sense to mandate a double pole switch. If you want to ensure your lamps are connected so that the switch is on live, use a non-contact voltage tester to test that there is no voltage when the switch is off. You could use an RCD plug and wire 6,8 kohm resistor between the ground and the neutral. This would ensure it is corrected the right way. Too bad could also trip the RCD in the panel.
Yes, US and Canada have the same voltage, frequency and socket/plug formats. Modern single-phase sockets are *always* 3 prong and plugs can be 2 prong (polarized) or 3 prong (with earth). Older 2 prong plugs may not be polarized, I see them on vintage radios and replace them with polarized as part of a restoration. No guarantee that some idiot did not wire the house up wrong though... I like the plug, cool idea.. I can see you making a business out of it (maybe :) ). It's more credible than those 5G radio wave traps (USB flash drives) Regarding the 1 dislike dude... well at least he is consistent. And there is only one of them on the entire planet. Cheers,
You really cannot make a business of it not allowed to use a schuko plug on a class 0 equipment. The sockets are specifically designed not to allow the plugging for safety reasons. While such a thing is reasonable for personal use selling it is not possible.
We have the same type of plug in Turkey. It is a very outdated and unsafe plug as you explained why. Some clever guy somewhere came up with an un-reversible version of it long time ago but I still don't see them used anywhere (maybe some applications where a UPS line is integrated in the building) It is a simple and effective design and it think it must be made mandatory by law in all countries that use this type of reversible plugs. Here is a pic: www.worldstandards.eu/wp-content/uploads/electricity-tiles-type-E-200-px.jpg
There is nothing wrong with the plug. It is the radio that is outdated.You are trying to dictate had of the world to change plugs. It is not going to happen. Note in Europe you cannot plug such a radio on modern grounded sockets. In the US with their superior plugs you could do it without realizing any problem.
wow the plugs u r forced to use there, OH My, they have an additional FLAW, in other places (Canada) the EARTH or Ground is ALWAYS the Longest Pin, that means whatever u connect anything it is GROUNDED FIRST before Power is applied, the plugs there the ground is the SHORTEST Pin that's really DANGEROUS.
Actually the holes for L and N are so far recessed in the socket that the Earth always connects first. I admit that the polarization is a design flaw in the "Schukostecker" how we call it in german, but everything else is very good about it. The plugs are sitting very stable in the sockets. I don't like it when the plugs hanging on an angle in the wall outlets in North America.
Electronics Old and New by M Caldeira, the problem is.....my Mom taught me that if you can’t say something nice, don’t say anything at all 😜 thanks for your videos!
Nice subject video. Also what an interesting location. You must get fantastic low band DX reception.
I suppose we do, as we have an open field of ocean all around.
Good idea, Manuel! To save space inside the plug, you could have used a small diode in parallel with the LED (to clip the reverse voltage across it)
Yes, that is definitely smaller.
I suppose u could use two LEDs (albeit installed in the radio). Green LED ON means all is OK. Red LED ON means chassis is LIVE. No LED on means GND is not connected. But if you are color blind it may be a problem.
😀
You also have a great sense of humor. Bless you. By the way, on the US plug, you got it right, the big prong is Neutral indeed. Some old houses however, might still have the old outlets where both prongs are the same side. Of course they have to be changed, or had to be changed, since all appliances going back to the 70s, have the polarized cords. some even have the ground pin. Now as to the 220/230 volts, i was in Greece when i was a kid and they have/had the same plugs there as what you are using. I also have a couple of Grundigs, that i love dearly with tubes. One has dual voltage input, while the 2nd is 110v only. They both date back to the 60s. Unlike you, i can't fix them, though i did have them repaired here, some time back. BUT, i love watching videos as informative as yours... Stay well and thank you again.
My pleasure. Thanks for your kind words.
M!
I usually enjoy your videos very much, and this one is no exception to that. Well thought out, informative, educational, practical, useful, helpful, entertaining, thought provoking...a darn good video!!!
You are right about the plugs in the United States of America...at least to a point. There is only one way that the plug will plug into the wall socket...however, unfortunately there are some places where whoever wired the house did not follow the code. In those cases, you can still get shocked. A device like yours could be useful here too. One thing I would have done differently though, is that I would have mounted the LED on the end where the power cord enters the plug. That way, it doesn't matter which way you plug in the cord, you could see the light easier. Still an excellent idea and well done.
On the subject of wiring, I once lived in a house in Georgia where the Dimwitt that wired it decided that AC is NOT polarized, and therefore it "didn't matter" which wire went where. Therefore he wired the house with black and white wires connected together in many places. I discovered it when I opened the refrigerator and the kitchen light went off. Closed the door and it came back on!
Again, really enjoyed the video!!!
Thanks for that.
As usual, a prototype always need a version 2: I had the same thought about the positioning of the led when I first used it. Next time 😊
I think the problem with doing this in the US is the size of the plugs - much smaller, if I’m not mistaken.
Wherever you go, dimwits will always leave their mark.
Manuel, Excellent safety workaround for a hot chassis set powered from your Portuguese non-polarized sockets.
Thanks
you got a way of explaining things! even people like me, not that well versed, get it. thank you again.
YES, that is one very important quality, or talent, that every tech related UA-camr must have. I follow more than 30 tech channels, some even with more than a million subscribers, only 2 or 3 of them can manage this.
I appreciate that!
I recall building a AC voltage tester in electronics shop using a ne-2 neon bulb and a resistor, no bridge rectifier needed. It draws micro amps of current and lasts a long time. Thank you for this safety tip.
pleasure
This is an elegant solution. In France they have the same plug but with an additional socket for ground. They wall socket has the same two connections plus a grounding pin which makes it impossible to reverse the connection. German plugs and sockets don't have the grounding pin arrangement. I'm definitely going to use this system.
Yes, the french ones are a great option.
The problem is that Czechia uses the same plug but with the opposite polarity. In Poland the polarity can be either way as I think was earlier in France. The pin is not intended to enforce polarity. Schuko at least allows you the choice to reverse.
Great idea and nice implementation. Another option would be to use a green LED wired to illuminate when the plug is correctly inserted. That way, if/when the LED fails, or an internal connection breaks, you know there is *some* problem: either plugged in backwards, or the plug circuit itself has failed. (Sorry - before retirement I was an embedded controls engineer for commercial equipment, meaning my first thoughts are always "What if it fails? What if they make a smarter idiot? What if ...").
But, the red=wrong is good, too. Red is the standard warning color, and with your method, you get a really clear indication that the plug is in wrong. Pay your money and take your choice, I suppose. Another advantage with your method is no extra leakage current when the plug is in correctly.
I agree with the “what if it fails” outlook. I tend to do that myself which is why I never seem to stop making changes to my designs. However, in this case, there are so many options that I had to force myself to stop at the one that did the job.
That crossed my mind, the dreaded "single-point failure". (medical devices here).
Excellent idea! I will do it too! We have the very same problem (and voltage) here in Chile. Thank you very much
You are welcome
Such a simple thing but makes things so much safer! Great video Manuel.
It really is!
Great tip , thanks now I am more confident in a restoring attempt because I am just as scared as you on getting zapped
Fear can be a good thing 😊
Hmmm. Interesting. I tend to steer away from hot chassis radios but have ended up with one and have been mulling over what kind of warning system I could put in place. It got me thinking. I have a feeling that this could be done with one of your LED converter boards. It would only catch the half wave of the cycle to iluminate the LED but I think it would give the same result (using a 220k resistor, obvioulsy!). The SMD board version is tiny so takes up very little space.
The plug version that I did works very well. Have a look at that video. I used a miniature bridge rectifier in it, and everything fit nicely on the plug.
This only doesn't work when you plug it into a non-earthed socket. I don't know about Portugal, but in The Netherlands (where we have the very same type of plug), many homes still have non-earthed sockets in most rooms. The earthed plugs do fit in there, but with the earth contact disconnected, the LED won't light.
True. Can’t solve every situation. In my case, I just want to know which way around to connect the plug, because I know I’ve got earth in here.
Not only in NL also in BE and GER the earth ground connection can be missing. Or as found often after rennovations, the tabs providing earth ground connection have been covered in wall paint. To inform of such a situation, the dangers involved and this indicator staying dark thus falsely indicating a proper orientation, there is an easy remedy; inside the plug place a 270-330k resistor from Live to earth ground. If earth ground is floating the LED will light either which way the plug is inserted. Also to make things easier and avoid the risk of placing big components in a small environment that has potentially 3kW of electrical power available befor the house wiring breaker trips, I would have used a single diode instead of a bridge rectifier to save on space. Or alternatively place a 1N4148 antiparallel to the LED.
Also there are LED available with two (!) antiparallel(!) chips in one case, so the LED can be used on AC without additional rectification. Most prominent are the bi color types where in one direction they light red and green the other. Subjected to AC thus u get an orangy color.
This modification is to allow the use in an earthed socket. You do not need it with non-earthed sockets. With non-earthed sockets the safety is based on the fact that there is no earth nearby. This is not ideal especially nowadays though as there are so many different equipment so it is hard to keep earth out.
Remember the old rule: if it fits, it is OK.
Very smart! I've done it several times with a Neon bulb.
👍
Older plus in the US are not polarized. But even polarized plugs can still be plugged in either way in most outlets. So your caution still applys to a hot chassis
Always pays to be careful.
Hi.Good idea, I appreciate it. However, here in Portugal (where I live too), a good portion of homes are very old and do not have ground line instaled. The outlets are flat without ground terminal or schuck standart outlet without any connection at ground terminal. Why not a single connection by one led in series with a resistor between Line and Neutral ? The orientation for the plug will keeped with no ground dependance, and less components inside the plug.
What is your opinion about ? Many thanks in advance and keep your good restorations.
I might try that.
Hi again. My apologise, I made a mistake. Thinking twice, my idea will not work as we are dealing with AC and the led will always light up. It is necessary a third point (ground) to be the reference between L and N. Never the less, my concern still on, lots of homes here in PT did not have ground line and the problem still open.
Correct. Didn’t think it though completely.
As for it’s use however, this is not a comercial design at all. It’s for my own use and therefore suits the purpose well.
I recall my grandparents’ house in the country having no ground at all, and tingles (if not outright shocks) were quite common. They had a rather strong respect for the wiring in the house 😊
In principle if you have ungrounded sockets you should not have ground potential nearby so you could use the original plug. In principle as modern homes are far more complex with antenna and data cables that can provide earth and there were compromises in the old rules.
There is no way to tell from an ungrounded outlet using the contacts the outlet gives which is hot an which neutral. You can do it one grounded outlet as the neutral and groudn are connected together or both are separately grounded.
Note that while the modification is reasonably safe, it is illegal at least in Finland.
The best is to determine in which position the chassis is neutral and mark that on the plug. As you use the same socket you have no problem.
👍
BTW with your Brymen you can also check if it's live or neutral
Yes, I’ve used it quite a bit before.
Hi
Thanks so much
Its a good way to reduce the risk of zap, in our country we have also the same problem with plug.
My pleasure
Great video, thank you !!!
pleasure
In Poland, we have an even bigger mess with it. There are sockets (old type C sockets) without grounding, non-polarized, and sockets with a male earth plug (type F), so theoretically they cannot be inserted the other way round. However, there is no law regulation, which side should be the live and which side should be neutral. It is described only as good practice among electricians to place the phase in the right pin.
the same problem here. every electrician has his own rules.
Great video. Do you actually need the rectifier? I would have thought with sufficient resistance it would not damage the LED and work without one just lighting on the half wave.
It would, but then you’d have the full reverse voltage across the led on the negative half-cycle, and that would not be good for the led. you could simply connect a diode in reverse across the led and that would work fine.
The plug has a ground connection to the wall but you don’t take a 3rd wire to the chassis?
In the US one plug pin is fatter than the other so we don’t have the option to do the flip. I have seen wall sockets that were reversed. So as a general rule I put three wires to the chassis.
But your solution allows for only two. I’ll keep it in mind.
This reminds me of my balanced power isolation transformer, where both pins go live after the secondary (60v each here in the USA)and the ground is in the middle. I use this for my ‘special tube audio’ system. An old friend who worked for Raytheon for 40 years and did life support medical equipment for them, he gave me the transformer and explained how to configure it for best and quiet operation and he swore it would be the safest setup too. Everything with the straightest connection to ground. The balanced power makes a big difference to the sound and all components are dead quiet.
I don’t take the third wife to the chassis because it is the point that has one of the mains lines attached to it.
This radio appears to have a double-pole on-off switch, which is good. There ere some radios where the on-off switch disconnects the wire from mains to chassis only. This means: if the radio is on, the chassis is at neutral (good), but if the radio is off, the chassis is hot again (not good).
Does the pickup input have capacitors isolating both lines from the circuit? So is there also a cap isolating the pickup ground input from the chassis? Most hot chassis radios (if they have a pickup input) have this, but not all.
If the radio is intact and the back plate is on, those radios are supposed to have no exposed metal parts that are connected to the chassis. That's the theory at least. We used to consider them safe, way back when.
This one actually has the pickup socket directly connected to chassis, so extremely dangerous.
Great idea 💡 . But wouldn’t it also work without the rectifier ? The LED will block on reverse polarization. Or will it blow when 230v are attached in reverse ? Just asking....
you can use two leds or a led and a diode in reverse, so that the reverse voltage across the led doesn’t exceed its max limit.
good work and great advice for lots of AC plugs, but here in the UK....
Yes, In the UK you’ve got some serious regulations.
Nice warning ...congratulations !!
Thanks
nice but would it not of been easier to use a neon (no need for bridge)
Either is fine. I prefer LEDs.
This is something that has been bothering me for some time, I am in the US and we do have polarized plugs. I have older equipment such as Yamaha stereos from the 70s and I never really understood why something had to be one way or the other. I am currently restoring a friends Sansui 551 reciever from 1975. it has an un-polarized plug. The existing plug and wire are in good shape. so I seem to have 2 options replace the end of the cord or replace the entire cord. I am not the owner so I need to let him make the decision. My preference is to replace the entire cord. in the mean time I just took a piece of painters tape and wrote big and small to the corresponding live and neutral prongs so at least I can choose to plug it in the best way. I plan to update all of my old stuff with polarized plugs that are wired correctly.
We all need to be a little more careful about mains polarity with older equipment. Speaking for myself, I know I get a little careless sometimes, and that can be a problem .
A lot of "vintage" audio gear, has it's line voltage "isolated" by going to a transformer, so, this is usually not a concern. Some antique radios that use a "series strung" tube filament design may have (here's where having and comprehending a schematic is a valuable skill) one side of the line cord, which usually was not polarized, directly connected to, or coupled with a low value capacitor (popularly called the "Death Capacitor") to the chassis, and these would be of concern. Those radios almost always have bakelite plastic or wood cabinets and plastic knobs so you would never touch an energized piece of metal by accident. Using a 2 prong polarized plug, or changing to one, is a good idea in those cases, but you are still at the mercy of the electrician that wired that outlet, and it is best to get a polarity tester and check outlets before use to verify they are wired correctly.
its indeed a very good and safe idea, never tought of it myself.
:)
In Australia our plugs are polarized, but my 1960 Schaub Lorenz has a plug with two flat pins so I will need to use an adaptor to suit an Ozzie plug. It could then be plugged in either way. Is this an issue with a radio which has a standard transformer which offers some level of isolation?
If it has a standard transformer, then the only issue is to see if the on/off switch actually switches off the Live. Not so much of a problem.
Neat. But in my house there are not many sockets with earth. Most are missing and that makes this plug not work.
True
I've seen something similar before but with a neon indicator.
That works well too.
I'm thinking one could fit that into the actual radio if pristine original condition isnt a concern. Thanks for sharing!
I did just that in quite a few previous cases.
Great channel. Congratulations!
I love the content!
I just thought how this will work in a home that's has IDR protection circuit. Would it be not a problem?
Shouldn’t be a problem as long as the system accepts a leakage higher than 1 mA before kicking in.
@@electronicsoldandnew Thank you :)
How does this possibly ever work? There is no earth connection in a 2 prong plug!
These plugs have an earth blade at the top and bottom. Have a closer look.
Interesting video as usual. Thanks.
Pleasure Jon.
Important topic. But since it‘s really dangerous I would have placed the led to the back, not to the side. And I also would have used a flashing/blinking one.
Going in at the back in version 2.0 :)
I had to sleep this over, and this might be a bit picky, but I think there is a minor issue with your design.
If I remember correct, the standard of the shelf 1/4W metal film resistor is rated for 250VDC max. 1/2W types usually are rated for 300VDC maximum working voltage. And those values apply for brand resistors. My worries arose by thinking someone may built something similar and using a resistor made of chiniesium...
Applying 230VAC, the peak voltage across the resistor is roughly 330VDC and thereby exceeding it's maxium ratings.
As this is a sort of of a "safety equipment", I would propose to use two resistors in series. Thereby droping the voltage across the resistors into a safe operating zone.
And yes, I know, these times you find the cheapest chiniesium 0603 resistors, rated for 75V at best, as bleeding resistor across capacitors in capacitor dropper circuits in every second LED-Lamp in your household and nobody gives a sh*t...
Good point. I mentioned a 600mW resistor in the video, but the same problem could apply. As the purpose is to swap the plug as soon as you see red, the power dissipation period is actually very short, but voltage flash-over could be a problem in really crappy resistors, as you say.
do you have same issue with washing machines and fridges?
Can’t answer that as my experience with those is limited, but I’d imagine that it could also be a problem.
Nice idea. How about adding a green one across live and earth, this should always be on and would show that the earth was present (which if it isn't would invalidate the red led test). I suppose the only issue could be if that was the "final straw" 1mA that makes the RCD trip :-). [update - in fact, would you just need the live/earth one - i.e. must be lit for radio to be safe?]
You’re a mind-reader Ross. That’s in the cards for version 2 👍
If there was no earth the socket would be unearthed. In that case it would be considered safe without any modification.
@okaro6595: the neutral is effectively earthed back at the switch-box, so definitely not safe.
Neon lamp can be a better option, with simpler circuit and lot less leakage current introduced.
To each his own 😊
Good invention and very simple!
But in a good condition radio you should have no easy acess to the chassis during normal operation. ususally there is wax covering the knob screw-holes and the screw is recessed. etc... maybe on some sets if you grab and move the radio with it plugged in you can get a shock, but that can be adressed mechanically (covering exposed screws underneath if they protrude) but usually that is taken care by the radio manufacturer. also there are certain situations were neutral can shock you too, lets say the neutral wire to the grid has a bad connection and you touch it, whatever current wants to flow throught the circuit will flow through you and to earth instead of the neutral, sometimes if you have wet feet etc you can feel a zap in the neutral.Your differential breaker should trip but it often doesnt.... i did a lot of domestic wiring for a company and during that time i took some neutral zaps. happens even more easily when there is lots of current flowing trough the wires for example when an electric heater is on etc etc. if the neutral offers resistance, if there is too much currint going through that wire and you touch it some of it will find a good path to earth trough your body
Personally i must have my vintage stuff with vintage plugs, i have a big radio that the wife uses but its a power transformer set, the rest of radios and tvs are only used by me and MORE IMPORTANT on vintage gear, ALWAYS unplug when not in use and never leave them on unatended, those are the golden rules for me. Cheers!
the main problem here is that the phono input ground is directly connected to the chassis, so if you connect something in there, ....
@@electronicsoldandnew on that radio its not 100% safe to use the phono input even if chassis is neutral..well, its better than live but still.....ideal situation would be a small 1:1 coupling transformer maybe???
No need for a bridge rectifier, just an anti-parallel diode connected to the LED. No need for any high voltage rating for the diode, a 1N4148 will do.
I prefer the bridge so that the diode does not flicker with the half-wave that results from the alternative solution.
@@electronicsoldandnew , you might want to edit the video to include that statement. Again, wonderful video...throughly enjoyed it!
You won't see any flicker (50Hz)
The flicker - if visible - doesn´t matter, because the plug has to be plugged in so that the LED doesn´t light and we have no permanent flicker; only for alarm. BTW, the antiparallel diode could be a second LED antiparallel and could be mounted on the other side of the plug so that at least one LED is always visible
Very good point. Thanks.
I was stationed in South Korea for a few years and they have the same plugs and voltage as Portugal. While living off-base, I got shocked once at 230V when I touched my American microwave with one hand and my kitchen faucet with the other. Turned out the step-down transformer that I was using, and which I'd bought in the Base eXchange along with the microwave, was faulty. It had a three-pronged outlet to fit American appliances but the maker had literally pulled the ground receptacle out so only the hot and neutral sockets were present. That was bad enough, and is actually "normal procedure" for Korea, but the fault in this case was present in the transformer windings. The shock hazard didn't go away until I replaced the whole transformer unit. Two tips for my American compatriots: 1. Watch out for those cheapie BX step-down transformers, many of them are death-traps, and 2. for those of you living in the US, you can pick up a cheap outlet tester in any big-box store for about 8 bucks and it will tell you immediately if your three-pronged 120V outlets are wired correctly. Mine was made by Commercial Electric and it was well worth the investment.
Many cheapie step down transformers are autotransformers, same issue as this Grundig.
@@rossthompson1635 Understand. So was mine. When I returned home from Korea I rewound it and converted it into a 1:1 isolation transformer (115V). It works well enough, but the 14 awg aluminum wire it had originally, and that I used to rewind it, makes it rather inefficient. Fortunately, I only need it to work intermittently until I can build the isolation-dim-bulb-variac device that I'm now collecting parts for.
👍
I would have put black heatshrink on instead of red as black is neutral on black red cables
Colour coding varies by country, so it’s just the colour at hand.
Just a danger setup... I hope nobody else than you is using that radio! In some old installations in PT we don't have even sockets with earth 😆. If you wanna save and use this nice radio, make it safe, replace the autotransformer!
Yes, Portuguese house wiring is not for the weak. But... I have this one and a few more that are risky, and I’m keeping them 😊
53 views and I see Dick the Troll has been here. Great video Manuel, as always.
Dick the Troll. I like that 😊
Hi, good idea and well done. Thumbs up (-;
thanks
This sort of circuit should be in every non-polarised plug.
We have never had the issue in Australia even with two pin plugs as our Live and Neutral pins are at an angle so it can only go in one way. That said, I have known plugs and even sockets to be wired incorrectly
That is a problem you can't get around, unless you get a tester and check your entire house.
And which way you would indicate the danger on modern equipment? Toss a coin? This is a very specific modification for very specific application, nothing more.
@@okaro6595 if modern equipment is wired CORRECTLY there would be no issue.
Incorrectly wired devices we cannot compensate for, and these would not pass any tests or certification anyway.
This plug modification is perfect for polarisation, which is all it was ever designed for
That is what it’s presented as.
@@EsotericArctos Yes, it is a good option for this problem. It is a good hobbyist solution, not for a layman as it still requires activity form the user and it also is not to the code. Polarization is really issue only on lamps and it would make more sense to mandate a double pole switch. If you want to ensure your lamps are connected so that the switch is on live, use a non-contact voltage tester to test that there is no voltage when the switch is off.
You could use an RCD plug and wire 6,8 kohm resistor between the ground and the neutral. This would ensure it is corrected the right way. Too bad could also trip the RCD in the panel.
That's KISS at its best.
😃
I am also natural cowherd... But I like your solution
👍
Yes, US and Canada have the same voltage, frequency and socket/plug formats. Modern single-phase sockets are *always* 3 prong and plugs can be 2 prong (polarized) or 3 prong (with earth). Older 2 prong plugs may not be polarized, I see them on vintage radios and replace them with polarized as part of a restoration.
No guarantee that some idiot did not wire the house up wrong though...
I like the plug, cool idea.. I can see you making a business out of it (maybe :) ). It's more credible than those 5G radio wave traps (USB flash drives)
Regarding the 1 dislike dude... well at least he is consistent. And there is only one of them on the entire planet.
Cheers,
always a good idea to play it safe.
You really cannot make a business of it not allowed to use a schuko plug on a class 0 equipment. The sockets are specifically designed not to allow the plugging for safety reasons. While such a thing is reasonable for personal use selling it is not possible.
Agreed.
Always nice videos, would it not be nicer to mount the LED on the cable side, so you have a better view of the LED.;-)
Definitely going into version 2 :)
Very valid circuit for your predicament.
😊
Excellent, but sure glad this isn't a problem in the US!
The guy that dislikes, must *NOT* know how to spell electronics! *WHAT* *A* *JERK !!!!*
😊
We have the same type of plug in Turkey. It is a very outdated and unsafe plug as you explained why. Some clever guy somewhere came up with an un-reversible version of it long time ago but I still don't see them used anywhere (maybe some applications where a UPS line is integrated in the building) It is a simple and effective design and it think it must be made mandatory by law in all countries that use this type of reversible plugs. Here is a pic:
www.worldstandards.eu/wp-content/uploads/electricity-tiles-type-E-200-px.jpg
Yes, that is what they use in France as standard, I believe. We need them here too.
There is nothing wrong with the plug. It is the radio that is outdated.You are trying to dictate had of the world to change plugs. It is not going to happen. Note in Europe you cannot plug such a radio on modern grounded sockets. In the US with their superior plugs you could do it without realizing any problem.
@@okaro6595 You didn't get what I was talking about.
wow the plugs u r forced to use there, OH My, they have an additional FLAW, in other places (Canada) the EARTH or Ground is ALWAYS the Longest Pin, that means whatever u connect anything it is GROUNDED FIRST before Power is applied, the plugs there the ground is the SHORTEST Pin that's really DANGEROUS.
Actually the holes for L and N are so far recessed in the socket that the Earth always connects first. I admit that the polarization is a design flaw in the "Schukostecker" how we call it in german, but everything else is very good about it. The plugs are sitting very stable in the sockets. I don't like it when the plugs hanging on an angle in the wall outlets in North America.
It seems that wherever you are, there are issues, so being careful is the ultimate safety check.
I’ll need to dislike more often then😂
As often as you like 😊
Electronics Old and New by M Caldeira, the problem is.....my Mom taught me that if you can’t say something nice, don’t say anything at all 😜 thanks for your videos!
That's KISS at its best.
true