MOTM

>  > 1 - can i use the VTL5C3 in my TLN156, and how do i measure which 
>leg to use
>>  (the LED part seems obvious)
>
>Just leave the middle wire open.
>AFAIK, the VTL5C3/2 is just a center tapped VTL5C3.
>
>You can also just use one half of the cell (leave
>one of the outer wires open) and get 1/2 the resistance,
>or even connect the two halves in parallel (short the
>two outer wires together) and get 1/4 the resistance.
>As these devices have rather high tolerance, you might
>try the different options and see what fits best into your
>application.

These are good ideas, thanks JH. I didn't realize the VTL5C3 was 
difficult to get in Europe. Nice to know there's an option.

I just looked at the spec sheets for the 5C3 and 5C3/2 and, like the 
man says, the 5C3/2 is pretty much a 5C3 with center tap. You should 
be able to clip out the middle wire and solder it onto the board.