Safe sound input in bathroom

[OwainDIYer]

Even if the screens are earthed, if the power supply fails mains could be present on the internal circuitry, which would extend to the tip of the 3.5mm plug going into the i-device.

So the options would seem to be:

verify the amplifier has appropriate isolation built in;
use an appropriate isolating transformer on the audio input;
supply the amplifier from an apporpriate isolating transformer (like a shaver supply unit, but that won't be powerful enough);
just wire it up anyway as it'll probably not kill anyone.

I can't recommend the last but it's what I've done in my bathroom.

 

[Ninemill]

Thanks again for the replies. Out of interest, could you point me towards what you'd call "an appropriate isolating transformer on the audio input"?

The amplifier is one I've been given by a friend and I think it does have some kind of protection built in.

On reflection, this kind of risk must be present in any piece of home entertainment equipment. I wouldn't worry about unplugging my iPod from the hifi in the lounge and touching the metal plug - and the exact same internal circuit failure could have happened there.

 

[JohnW2]

On reflection, this kind of risk must be present in any piece of home entertainment equipment. I wouldn't worry about unplugging my iPod from the hifi in the lounge and touching the metal plug - and the exact same internal circuit failure could have happened there.

Exactly. I dare say some will argue that the risk is greater in a bathroom because you're more likely to be wet and/or in contact with earthed metalwork (e.g. taps) when you touched the iPod plug. However, I think you are far more likely to suffer injury by, say, slipping in the bath - so I personally think that some common sense is needed here.

Kind Regards, John

 

[OwainDIYer]

audio isolating transformers are readily available, but whether they'd meet the requirements for isolation for safety I couldn't say. They're usually used to stop earth loops in audio circuits.

http://www.canford.co.uk/Products/2...LATING-UNIT-Single-channel-600-ohms-XLR-inout

http://www.misco.co.uk/Product/154244/Stereo-Audio-Isolation-Transformer

http://proto-pic.co.uk/transformer-modem-600-600-ohm-pth/

 

[Ninemill]

Cheers, thanks for the links, and all the advice and feedback. Much appreciated - I'm now suitably reassured!

 

[bernardgreen]

but whether they'd meet the requirements for isolation for safety I couldn't say.

The transformer I use for this type of situation is the ETAL 1200 which has a 3.88 Kv isolation at 50Hz when correctly installed on a PCB

http://www.tscomponents.com/products/ETAL_Data_Sheets/data1200 _ETALDOC71_[1].pdf

 

[JohnW2]

The transformer I use for this type of situation is the ETAL 1200 which has a 3.88 Kv isolation at 50Hz when correctly installed on a PCB
http://www.tscomponents.com/products/ETAL_Data_Sheets/data1200 _ETALDOC71_[1].pdf[/QUOTE]
Fair enough, but would you really feel it necessary in the situation the OP described?

Kind Regards, John.

 

[bernardgreen]

Fair enough, but would you really feel it necessary in the situation the OP described?

Whether it is necessary can only be determined by knowing the quality of the build of the amplifier's mains power unit.

Remember that potential differences between "grounds" of guitar amplifiers and microphone amplifiers have given stage performers significant electrical shocks.

 

[JohnW2]

Fair enough, but would you really feel it necessary in the situation the OP described?

Whether it is necessary can only be determined by knowing the quality of the build of the amplifier's mains power unit. Remember that potential differences between "grounds" of guitar amplifiers and microphone amplifiers have given stage performers significant electrical shocks.

True (indeed, people have been killed by guitars) - but that's a general truth. I meant in the context of this thread. We are presumably talking about am amplifier which, for better or for worse, the OP and most others would be happy to use 'as is' without even dreaming of the need for any additional input isolation were the input coming from anywhere other than a bathroom.

Kind Regards, John.

 

[bernardgreen]

[the OP and most others would be happy to use 'as is' without even dreaming of the need for any additional input isolation were the input coming from anywhere other than a bathroom

I fully agree with that, lack of awareness in the general public creates that complancy but change "dreaming" to "thinking" and the potential hazards might then be seen.

 

[JohnW2]

[the OP and most others would be happy to use 'as is' without even dreaming of the need for any additional input isolation were the input coming from anywhere other than a bathroom

I fully agree with that, lack of awareness in the general public creates that complancy but change "dreaming" to "thinking" and the potential hazards might then be seen.

We obviously don't know the vintage of this amplifier, but if it had been bought in the last decade or three, I really don't think that hardly anyone would think (or dream) of the need to add a safety device between it and an input device/lead to render it safe to use!

Kind Regards, John.

 

[westie101]

But again looking at the op's plans, apart from the initial set up, who will be touching the metal pins of the 3.5mm plug?
He is planning to use a docking station for the iPod so that will merely slot in to a plastic holder!

 

[JohnW2]

But again looking at the op's plans, apart from the initial set up, who will be touching the metal pins of the 3.5mm plug? He is planning to use a docking station for the iPod so that will merely slot in to a plastic holder!

I know. I think this whole discussion is a classic illustration of how advice, practices and regulations concerning safety can get a bad name, and come to be treated with contempt (thereby undermining their important intent) - by going OTT in relation to minute hypothetical risks.

As I said a good few posts back, where has common sense gone? I still reckon that slipping in the bath is a far more likely cause of injury in the bathroom in question!

Kind Regards, John

 

[westie101]

At the end of the day I wonder how some folk live!
Going out in the street is a risk, driving a vehicle is, yet they do this day in, day out! Yet then seem to come out with the most minute hazard when someone wants to do some work or fall back to the "the book says"

Sorry but I'm rapidly getting fed up of the unprofessional way that folk act on here.
It seems that if they have quoted the book all is OK, though I suspect that after NOT getting advice on here in most cases folk are just going away and doing their own thing

THAT IS DOING ABSOLUTELY NOTHING FOR SAFETY AT ALL!
IT IS JUST FOLK COVERING THEIR OWN BACK AND IS ACTUALLY ABOUT LITIGATION RATHER THAN SAFETY.

Perhaps the next time an electrician rings me for advice I should consider it job done by referring them to BS7671 or ESQCR.

 

[matt1e]

Fair enough, but would you really feel it necessary in the situation the OP described?

Whether it is necessary can only be determined by knowing the quality of the build of the amplifier's mains power unit.

Remember that potential differences between "grounds" of guitar amplifiers and microphone amplifiers have given stage performers significant electrical shocks.

Yes bernard but that senario only happens when using multiple equiptment
The op is using only one amp

Matt