ODP: 3rd Re: ODP: optical pots 2

[Paul Perry]

>strip?
>> > If you push your tumb and indicator of the strip adjacent to the >
>poles
>> > of the battery, a chemical reaction starts an colors the strip >
>yellow.

surely this is a heating reaction?
the battery current (if any) heats a strip and a temperature
sensitive pigment changes color...
I always buy $2 batteries which dont come with these frills..
anyone with a soldering iron want to try one out?

paul perry melb australia