Convert US standard 115V to International 230V

[radiolistener]

I believe the OP is just not qualified or certified and should not be making this type of decisions.

There are too many unknown variables and the OP is, clearly, not qualified. A medical device sold professionally and for export and this is how it is being designed?  In America? Really? Nobody thinks there is something wrong in this scenario? Really?

Completely agree. I wanted to politely bring the topic to the point that this is not easy decision for medical devices, because there are too many pitfalls which is not visible for non medical devices staff, but it appears that discussion going into wrong direction and my attempt was failed. Unfortunately some users decided that since they see simple and easy solution, they can just ignore medical devices specific and advocate their solution as the best solution and fiercely rejecting and criticizing all arguments against.

[tooki]

No, the wording doesn’t say the power consumption is in the capacitor

Yes, I see, but you wrote it in that way that it looks like I was said that capacitor will consume power. But that's not true.

No, I did not say that, and neither did Zero999.

just that you thought adding the capacitor increased power consumption in total

No. I don't have that thought.

Which is something you stated in the thread over and over and over.

I didn't stated that. I was talk about different thing.

Yes, you did, and you said it repeatedly in many different ways. If what you said isn’t what you meant, then you need to be a lot more careful in what you say and how you say it.

After all, I don't understand - what is the reason to link that discussion in this topic? Could you please clarify?
I think it will be more correct to discuss it in original topic. Isn't it?

I think you’re confusing me and Zero999. They posted the link, not me. Again, you need to read carefully.

And that was the whole point: you don’t listen, you don’t read carefully. You are frustrating because you read the thread poorly, then reply with something that is not relevant and not helpful. And you do this a lot.

We could substitute “reading comprehension” for listening, and you just proved our point: you don’t listen, or in this case, read carefully. You’re seeing what you want to see, not what’s actually written.

You're just pull an owl on a globe.

I have no idea what that is supposed to mean. I think that’s a word-for-word translation of some idiom in Ukrainian (every example of it, when googled, was from Ukrainian sources), but in English it has no meaning.

It looks like you're see what you want to see, not what actually is.

So you’re just childishly pretending you can turn it around and say the same about me? “No I’m not, YOU are!” is literally what little kids say to each other. Meanwhile countless people on the forum have made the same observation about you as I did. You. Don’t. Listen. And that is super frustrating.

Really, I don't see the reason for your aggression. You are acting like a bully, trying to find a reason to quarrel. For what?

It is not aggression, it’s frustration.

Сould you please calm down and communicate on the topic instead of expressing your subjective opinion about persons?   

Somehow we need to get through to you that you have got to be more receptive to feedback and more accepting of others’ expertise, and to make a real effort to read carefully and thoroughly before responding to threads.

[radiolistener]

Somehow we need to get through to you that you have got to be more receptive to feedback and more accepting of others’ expertise, and to make a real effort to read carefully and thoroughly before responding to threads.

I don't know why you decided that I don't listen to feedback. Regarding to the point that OP uses PSU which is already compatible with both standard, I heard this argument and accepted it. But I didn't agreed that this is enough info to make decision that there is no change required for medical device. IanB tried to ague that the medical device power consumption can be checked with a cheap Chinese meter and that information can be used to decide if used power supply is enough. But I argued that such approach is not acceptable for medical devices. Then Zero999 decided to support IanB mistaken idea that there is nothing to worry about and all can be checked with cheap meter. And then you're join and support Zero999...

As I can see you're didn't listen to my feedback. Instead you're started to blame me that I don't listen.

Usually person starts to blame some other person when he don't have enough knowledge for proper argument on the subject, that's the child way for discussion. And I see that you're started to talking about persons instead of topic subject. Isn't it?

I already proposed you to talk about technical subject instead of sharing your zero-cost subjective opinion about persons. If you don't have technical arguments, then I leave that discussion.

[tooki]

Somehow we need to get through to you that you have got to be more receptive to feedback and more accepting of others’ expertise, and to make a real effort to read carefully and thoroughly before responding to threads.

I don't know why you decided that I don't listen to feedback. […]

Because you don’t, and that entire reply is proof of this. You just bark back, but never accept responsibility for mistakes, nor accept that others are correct. Look at the part of my sentence above that is in italics. (And which was in italics in the original.)

Your first reply in this thread, long after OP had listed the part numbers of the power supplies used, you suggested 1. using a motor-generator set, and 2. to consider switching to an SMPS inside.

Both of those suggestions are completely irrelevant and useless at that point in the discussion because it had already been established that it uses two universal-input SMPSs. This shows you did NOT read the discussion before replying. When this was pointed out to you, you responded that the total power didn’t add up, even though this also had already been explained in the prior discussion. Rather than just saying “oh crap, sorry, I responded before reading everything” or “my apologies, you’re right, I missed that detail when reading” (which are things that happen to ALL of us!), you just keep digging and digging for why you can’t possibly be wrong… And that’s why people (plural) got annoyed, and expressed that.

[BeBuLamar]

IanB suggested to use the Kill-a-watt which is kind of cheap but it's not Chinese. It's Taiwanese. The Taiwanese is not pleased if you call them Chinese.

[radiolistener]

Because you don’t, and that entire reply is proof of this. You just bark back, but never accept responsibility for mistakes, nor accept that others are correct. Look at the part of my sentence above that is in italics. (And which was in italics in the original.)

Your personal subjective opinion about persons is off-topic.

Your first reply in this thread, long after OP had listed the part numbers of the power supplies used, you suggested 1. using a motor-generator set, and 2. to consider switching to an SMPS inside.

Both of those suggestions are completely irrelevant and useless at that point in the discussion because it had already been established that it uses two universal-input SMPSs.

This shows you did NOT read the discussion before replying.

When I posted my first reply in this topic I didn't seen complete list of power supplies which are used on OP device. And correct me if I'm wrong, there is still no such list. Also I noted in the first OP post that his device power consumption is about 2300 Watt. And two PSU which he later provided for example is about 750-900 Watt in total, which is just about 40% of total device power consumption. So there is no way to decide if all of his PSU are compatible with all mains standards. I already explained it, but for some reason you're didn't read it.

I don't see why my post is completely irrelevant, the second part covers SMPS with universal input.

But even if all of their PSU are compatible with all mains standards, that is not enough to claim that medical device which uses these PSU will be compatible with all mains standards.


Regarding to the mains filter mentioned by IanB, it doesn't related with 50/60 Hz at all, their goal is to remove common mode currents in order to reduce EMI. I was talked about different filter which is used on device sensors ADC and in DSP stack to reject 50 or 60 Hz carrier from measured signal which appears due to interference from mains wires and due to leakage through PSU. It is software configured depends on used user environment. In medical device some signals working range may be very close to 50/60 Hz and even may cover that frequency and needs to be carefully processed with take into account the frequency of used mains line. Because interference level from mains frequency is pretty strong and it's presence can affect measurement results. This is why using PSU with universal input is not enough to decide that device is compatible with all mains standards.

[tooki]

Your first reply in this thread, long after OP had listed the part numbers of the power supplies used, you suggested 1. using a motor-generator set, and 2. to consider switching to an SMPS inside.

Both of those suggestions are completely irrelevant and useless at that point in the discussion because it had already been established that it uses two universal-input SMPSs.

This shows you did NOT read the discussion before replying.

When I posted my first reply in this topic I didn't seen complete list of power supplies which are used on OP device. And correct me if I'm wrong, there is still no such list. Also I noted in the first OP post that his device power consumption is about 2300 Watt. And two PSU which he later provided for example is about 750-900 Watt in total, which is just about 40% of total device power consumption. So there is no way to decide if all of his PSU are compatible with all mains standards. I already explained it, but for some reason you're didn't read it.

I did read your explanation, but AGAIN you missed the fact that OP clarified before your first reply that the 20A input was NOT the actual maximum input current established by some empirical means, but a mystery number from a long-gone employee. The list of power supplies shown is the entire list of loads in the device. This was already explained to you by someone else and you STILL don’t seem to grasp it.

I don't see why my post is completely irrelevant, the second part covers SMPS with universal input.

By fully understanding the thread up to the point where you first replied, you would have already known that all of the system is powered by the two SMPSs, both of which are already universal input. So you’re suggesting doing what it already did.

[soldar]

The Taiwanese is not pleased if you call them Chinese.

I could argue with that but I won't because it would lead to a sterile tangent.

[radiolistener]

IanB suggested to use the Kill-a-watt which is kind of cheap but it's not Chinese. It's Taiwanese. The Taiwanese is not pleased if you call them Chinese.

The point was is that using blind method to determine device specification with some meter is not acceptable for medical devices. Just because it don't cover all possible modes and as result it may lead to unexpected failure of device in future and as result uncontrolled risk for the patient life. In addition any measurement equipment used for medical device testing requires to be validated.

What is the risk of smartphone charger failure? It can kill the user, you probably hear about these incidents...
Medical device should not allow such kind of risk.

[radiolistener]

but AGAIN you missed the fact that OP clarified before your first reply that the 20A input was NOT the actual maximum input current established by some empirical means, but a mystery number from a long-gone employee.

Yes, when I posted my first message in this topic, I didn't notice that he don't have other power supplies and 20A is a mystery number.
And what? This is the reason you're attacking me? 

Sorry, but it looks very strange from my point of view.

By fully understanding the thread up to the point where you first replied, you would have already known that all of the system is powered by the two SMPSs, both of which are already universal input. So you’re suggesting doing what it already did.

And? I don't see a big problem here. It was clarified in the followed messages and we just follow forward. Isn't it? What is the reason to return back again and again?

And I don't see why it leads to such kind of aggression and attempt to shift discussion to persons instead of technical topics?

Don't you think you're fixated on some nonsense which makes no sense to devote so much time?

[tooki]

but AGAIN you missed the fact that OP clarified before your first reply that the 20A input was NOT the actual maximum input current established by some empirical means, but a mystery number from a long-gone employee.

Yes, when I posted my first message in this topic, I didn't notice that he don't have other power supplies and 20A is a mystery number.
And what? This is the reason you're attacking me? 

Not attacking. Explaining our frustration.

[sanleontexas]

The transformer really doesn't care if it's 50 or 60 Hz, it'll run fine either way. If it's a
50Hz transformer it'll actually run slightly cooler at 60Hz because it may have more
copper in it. And a SMPS will generally also run OK at either line frequency.
Unless there's some kind of frequency sampler circuit that wants to see a particular
line frequency(which would be rather odd), it's not worth the bother to design the
device for one or the other.

 

[TimFox]

As a practical matter, most modern electronic equipment is designed to work equally well at 50 or 60 Hz.
The more likely problem is 100 vs 120 vs. 240 V.
Possible exceptions include "Sola transformers", which are less popular now, that depend directly on the frequency, or motors whose speed depends directly on frequency.

[tooki]

The transformer really doesn't care if it's 50 or 60 Hz, it'll run fine either way. If it's a
50Hz transformer it'll actually run slightly cooler at 60Hz because it may have more
copper in it. And a SMPS will generally also run OK at either line frequency.
Unless there's some kind of frequency sampler circuit that wants to see a particular
line frequency(which would be rather odd), it's not worth the bother to design the
device for one or the other.

There is no transformer, just two SMPS.

[tooki]

As a practical matter, most modern electronic equipment is designed to work equally well at 50 or 60 Hz.
The more likely problem is 100 vs 120 vs. 240 V.

It’s already established that the device runs on two universal-input SMPSs. Model numbers much earlier in the thread.

[soldar]

The transformer really doesn't care if it's 50 or 60 Hz, it'll run fine either way. If it's a
50Hz transformer it'll actually run slightly cooler at 60Hz because it may have more
copper in it. And a SMPS will generally also run OK at either line frequency.
Unless there's some kind of frequency sampler circuit that wants to see a particular
line frequency(which would be rather odd), it's not worth the bother to design the
device for one or the other.

If you bother to read the thread you will learn that this is not relevant or applicable.

And, as a general statement it is also wrong.

[Jwillis]

The transformer really doesn't care if it's 50 or 60 Hz, it'll run fine either way. If it's a
50Hz transformer it'll actually run slightly cooler at 60Hz because it may have more
copper in it. And a SMPS will generally also run OK at either line frequency.
Unless there's some kind of frequency sampler circuit that wants to see a particular
line frequency(which would be rather odd), it's not worth the bother to design the
device for one or the other.

On a SMPS, frequency of the mains voltage doesn't matter because the mains power is rectified to DC then the frequency is set by the PWM for the transformer.

[soldar]

On a SMPS, frequency of the mains voltage doesn't matter because the mains power is rectified to DC then the frequency is set to a by the PWM for the transformer.

You have to be very careful when making such very general statements. A SMPS designed for 60 Hz will have greater ripple at the capacitor when connected to 50 Hz. Most of the time the capacitor will have enough margin but if the capacitor is very tight initially or if it loses some of its capacitance it could lead to problems.

[Jwillis]

On a SMPS, frequency of the mains voltage doesn't matter because the mains power is rectified to DC then the frequency is set to a by the PWM for the transformer.

You have to be very careful when making such very general statements. A SMPS designed for 60 Hz will have greater ripple at the capacitor when connected to 50 Hz. Most of the time the capacitor will have enough margin but if the capacitor is very tight initially or if it loses some of its capacitance it could lead to problems.

I agree that the statement is a simplified explanation of how a SMPS works. But if you look at main stream switching power supplies on the market they are designed for a broad range of frequencies and input voltages. You need to choose a power supply rated for the application to which it is intended. There are SMPS's rated for medical applications. So why reinvent the wheel just get a power supply rated for your application.
Electrolytic's  standard testing is between 100Hz 20C^o and 120Hz at 25C^o. The DC ripple in a SMPS after rectification is either 100Hz or 120Hz.
Electrolytic capacitors show very little change to behaviour between 10Hz and 1kHz depending on temperature. So to say that there would be any significant change in behaviour between 50Hz and 60Hz at an ambient temperature of 20C^o to 25C^o is over thinking that a problem can occur. https://www.cde.com/resources/technical-papers/AEappGuide.pdf

[soldar]

I agree that the statement is a simplified explanation of how a SMPS works. But if you look at main stream switching power supplies on the market they are designed for a broad range of frequencies and input voltages. You need to choose a power supply rated for the application to which it is intended. There are SMPS's rated for medical applications. So why reinvent the wheel just get a power supply rated for your application.
Electrolytic's  standard testing is between 100Hz 20C^o and 120Hz at 25C^o. The DC ripple in a SMPS after rectification is either 100Hz or 120Hz.
Electrolytic capacitors show very little change to behaviour between 10Hz and 1kHz depending on temperature. So to say that there would be any significant change in behaviour between 50Hz and 60Hz at an ambient temperature of 20C^o to 25C^o is over thinking that a problem can occur. https://www.cde.com/resources/technical-papers/AEappGuide.pdf

You are missing my point. It has nothing to do with SMPS. The point is that a bridge rectifier followed by a capacitor is highly dependent on frequency because the capacitor needs to hold enough energy to power whatever it powers during a longer time, until the next pulse to recharge it comes along. Lower the input frequency and you increase the   ripple, decreasing the voltage level to which it falls. If you reduce the frequency by 50% you need to double the capacitance in order to maintain ripple and not increase voltage drop. It does not matter what follows, SMPS, linear or whatever.  I have dealt with adapting 120 V, 60 Hz machines to 220 V 50 Hz, including linear PSU, motors and transformers and I am quite familiar with the issues. That was long time ago, in a previous life.