On Sat, 6 Sep 2008 05:59:07 -0600, "WJW" wrote:

:Hello...a quick question looking for a good suggestion/solution/answer,
:
:1) I have a small rural nursing school;
:2) I have a $500 electronic stethoscope (micro-battery powered) that can
:hear/play/record sounds using an I-Pod by using a direct wire/plug into the
:I-Pod external microphone jack;
:3) I-Pod sounds are very weak and you have to be within inches to hear the
sound
:during playback;
:4) I need a room full of 10 students to hear the sounds from the stethoscope;
:5) I connected it to a wall-plug store-bought powered I-Pod speaker sound
system
:and it worked great...everybody in room could hear the sounds fine!;
:6) Was then informed it could possibly be a major shock hazard (110 power from
:wall through speakers to stethoscope to person wearing (ear pieces) and to
atient's chest (diaphragm);
:7) So...now I'm back to Step 1 & 2...
:
:Any suggestions on how I could truly prevent a surge danger for under $100
bucks
:so that I can safely use the stethoscope and the powered speaker system?
:Would an automotive quick-jump power pack with 110 inverter work or would the
:danger still be present? Is there really even a danger in the first place?
:
:Thank you very much for your wisdom, advice and expertise!
:
:William in Colorado



You could buy a medical grade 120V/120V isolation transformer to power your
speakers from but that will still be fairly expensive but you will probably have
to sort out the socket outlet for the plug-pack. You would still have the
problem that somebody could unwittingly operate the system without using the
transformer. Not a problem if you are the only one looking after and using the
equipment.

Ideally, you need equipment suitable for a teaching environment.
eg. http://www.stethoscope.com/index.cfm...&ProductID=132

If the cost seems high then you will at least be supremely confident that nobody
will have their safety threatened, and that can save a lot of worry about
lawsuits.