Re: Hearing aids, Inductive loops question

martin griffith scrobe on the papyrus:

On 1 Jul 2006 10:31:16 -0700, in sci.electronics.design "Mark"
<makolber@xxxxxxxxx> wrote:


martin griffith wrote:
My partially deaf neighbour cant afford to install an inductive
loop >> in her living room so she can hear the TV through the T
position on >> her hearing aids.

I've offered to see if I can make one, in exchange for home cooked
food. This seems like a fair exchange

A bit of googling suggests that a 25way cable, wired as a coil,
fitted >> around the ceiling edge will suffice.( approx 3m by 4m)

Any idea how much drive is required for the loop. I was thinking
of a >> 741 and a T0220 npn/pnp output pair, run off +- 15V as a
starting >> point.

Any comments, better configuration info, bandwidth limits. etc.
would >> be appreciated


martin

the folks over at rec.audio.pro may be able to help you..

My GUESS is it would take at least a several Watt ampllifier...


Mark
well, RAP does have a couple of experts, but there is generally more
chaff than wheat there, I'll go with what Nico suggested.

I'll probably scale it down to cover the sofa area to start off with


martin

It depends on how much spare time you've got, but you might do better
to buy the amplifier and cable here:

<http://www.applesoundshop.co.uk/acatalog/AVX_Loop_Amplifiers.html>

They even sell tape to fit under carpets.

--
John B
.