I have an extractor fan in the bathroom.

It is controlled both by a humidistat (separate, not built in) and also
by a ceiling pull switch for manual operation. Supply splits to feed
both of these, then runs to the fan where they terminate at the same
point. Problem is if the fan is on I don't know if it has been turned on
and left on or if the humidistat has switched on. So an indicator would
be useful.

I tried a neon indicator in the switch but this doesn't work - it
light's up if the humdistat turns on anyway - I guess because there is a
current flowing back down towards the switch.

Suggestions as too how can I arrange things so the indicator light on
lights when it is switched manually would be welcome.
--
Chris French, Leeds

"chris French" wrote in message
...
I have an extractor fan in the bathroom.

It is controlled both by a humidistat (separate, not built in) and also
by a ceiling pull switch for manual operation. Supply splits to feed
both of these, then runs to the fan where they terminate at the same
point. Problem is if the fan is on I don't know if it has been turned on
and left on or if the humidistat has switched on. So an indicator would
be useful.

I tried a neon indicator in the switch but this doesn't work - it
light's up if the humdistat turns on anyway - I guess because there is a
current flowing back down towards the switch.

Suggestions as too how can I arrange things so the indicator light on
lights when it is switched manually would be welcome.
--
Chris French, Leeds

Chris,

I know it can be done but have forgotten the fine detail, and besides the
electrician sorted it out.
I have a seperate humidisat, pull switch (with indicator neon) and timer.
All these are then isolated by a switch in the airing cupboard.
So if I use the pull switch, or if the humidistat cuts in, the timer starts
the fan and keeps it going for a set period after the switch or humidistat
turns off.

Briefly:
If the pull switch is on, the neon in the switch lights brightly.
If the pull switch is off but the humidistat/timer is on, then the neon in
the switch glows dimly.
Everything off, no light.

I presume an extra wire or wires goes from the timer back to the pull switch
with some kind of additional resistance to make the light glow, but dimly.

I leave the detailed design to the theoreticians of the group.

HTH
Dave R

"Toby" wrote in message
...
snip

Isolating relay?
Switch indicator relay coil output fan
humidistat fan

Sorry it's not very elegant solution, shame they didn't put an led on the
stat.
Or 40A pull switch with an on/off mechanical indicator in the base? Quite
rare.
A plate switch outside the door?

Toby.

Homebase have a 30A pull switch with mechanical indicator by MK.
Designe for isolating power showers where it could be dodgy if the neon
went.
Under £12.
I bought one for my bathroom fan (after trying to reuse the old switch from
a power shower which was unfortunately naffed).
Looked for a lower spec one - fan draws minimal current - but this was all I
could find and time is sometimes money :-)
Less elegant than the bright/dim neon, but a good solution.

In message , Toby
writes
"chris French" wrote:
I have an extractor fan in the bathroom.

It is controlled both by a humidistat (separate, not built in) and also
by a ceiling pull switch for manual operation. Supply splits to feed
both of these, then runs to the fan where they terminate at the same
point. Problem is if the fan is on I don't know if it has been turned on
and left on or if the humidistat has switched on. So an indicator would
be useful.


Isolating relay?
Switch indicator relay coil output fan
humidistat fan

Sorry it's not very elegant solution, shame they didn't put an led on the
stat.

That's all rather more effort than I want to go to. - yes it is a shame
there isn't a led on the stat.

Or 40A pull switch with an on/off mechanical indicator in the base? Quite
rare.
A plate switch outside the door?

The ceiling switch is a possibility, though not one I really want to go
with. The landing is nicely new plastered, I don't want to disturb that.

TBH, I'm looking for a cheap and fairly easy job, otherwise I'll just
leave it alone.
--
Chris French, Leeds