At 8:45 +1000 3/10/97, Peter Zaborski wrote:
>Thanks Jeff. I will try the multimeter this weekend and see what I can
>come up with. Just curious (and I know very little about electronics)
>why would I need a "wire wound" pot? What are the other types?
>
>Thanks again!
>
>Peter Zaborski
>76 TR6 (CF58310 UO)
>Calgary AB Canada
>
Peter
The other common type is built from carbon film rather than wire and it
cannot handle as much current and generally comes in higher (too high for
this purpose) values of resistance. It is usually possible to pick the
difference by turning the shaft - the feel of the slider travelling over
the wire is quite distinctive.
By my estimate (very approximate) the dashboard lighting requires about 20
Watt (10 x 2W bulbs) or about 1.5 to 2.0 Amps and the rheostat would have
to be able to handle similar current and probably a bit less power. Does
anyone have a new rheostat that could be used to measure the proper
resistance?
Keep going with this exercise, as I have exactly the same problem and you
have already determined that the problem is the rheostat and not the
cleanliness of the optical path in the instruments.
I am starting to wonder whether I really want a rheostat to vary the level
of instrument illumination - the rheostat position looks like a great place
to put a 2 inch Smiths vacuum gauge which I have somewhere in the garage.
If a rheostat is necessary, a concealed pot under the dash would be
satisfactory - it is hardly subject to constant adjustment. Sorry if this
offends the purists!
Trevor Jordan
74 TR6 CF29281U
|