out-of-control volume control -

[jack]

My earlier post (need help with a voltage-controlled-volume-control)
went out of control with concern about my safety and ears - so maybe
worth some clarification before someone sends me a hearing aid. The 5
watt stereo amplifier is driving 3 inch loudspeakers inside the helmet.
Works and sounds fantastic but I would like to add an automatic volume
control on the output of the iPod that would adjust the volume in
relation to the wind noise. ie .. I can't eliminate the wind noise but
I can adjust the volume of the music source (10-20 DB). I've read about
voltage-controlled-resistors using FET's but I have no experience with
this technology. Is it possible to build an attenuator with sufficient
dynamic range and linearity using FET's? Any help is very much
appreciated. Thanks again - sorry for the confusion I created on my
first posting - Jack.

 

[Pooh Bear]

My earlier post (need help with a voltage-controlled-volume-control)
went out of control with concern about my safety and ears - so maybe
worth some clarification before someone sends me a hearing aid. The 5
watt stereo amplifier is driving 3 inch loudspeakers inside the helmet.
Works and sounds fantastic but I would like to add an automatic volume
control on the output of the iPod that would adjust the volume in
relation to the wind noise. ie .. I can't eliminate the wind noise but
I can adjust the volume of the music source (10-20 DB). I've read about
voltage-controlled-resistors using FET's but I have no experience with
this technology. Is it possible to build an attenuator with sufficient
dynamic range and linearity using FET's? Any help is very much
appreciated. Thanks again - sorry for the confusion I created on my
first posting - Jack.

Fets are quite tricky to get good perfromance from in this application.

I already posted a link for resistive output optocouplers. These are very easy
to use.

Graham

 

[Mark]

pay attention to riding the MC instead of listening to music...

isn't that the point of riding?

Mark

 

[Rich Grise]

My earlier post (need help with a voltage-controlled-volume-control)
went out of control with concern about my safety and ears - so maybe
worth some clarification before someone sends me a hearing aid. The 5
watt stereo amplifier is driving 3 inch loudspeakers inside the helmet.
Works and sounds fantastic but I would like to add an automatic volume
control on the output of the iPod that would adjust the volume in
relation to the wind noise. ie .. I can't eliminate the wind noise but
I can adjust the volume of the music source (10-20 DB). I've read about
voltage-controlled-resistors using FET's but I have no experience with
this technology. Is it possible to build an attenuator with sufficient
dynamic range and linearity using FET's? Any help is very much
appreciated. Thanks again - sorry for the confusion I created on my
first posting - Jack.

That's simple. Just line the helmet around the speakers with noise-
cancelling foam, like on ear defenders and quality stereophones.

Good Luck!
Rich

(I also agree that your attention should be on driving, not kicking
back listening to tunes).

 

[Mac]

My earlier post (need help with a voltage-controlled-volume-control)
went out of control with concern about my safety and ears - so maybe
worth some clarification before someone sends me a hearing aid. The 5
watt stereo amplifier is driving 3 inch loudspeakers inside the helmet.
Works and sounds fantastic but I would like to add an automatic volume
control on the output of the iPod that would adjust the volume in
relation to the wind noise. ie .. I can't eliminate the wind noise but
I can adjust the volume of the music source (10-20 DB). I've read about
voltage-controlled-resistors using FET's but I have no experience with
this technology. Is it possible to build an attenuator with sufficient
dynamic range and linearity using FET's? Any help is very much
appreciated. Thanks again - sorry for the confusion I created on my
first posting - Jack.

You might build something around the ssm2164. It's kind of pricey,
especially considering the noisy environment you'll be listening
in. You'll need some kind of op-amp after it to convert current to
Voltage. Read the datasheet.

I still think you are going to go deaf. ;-)

--Mac