On 08/25/05 12:23 pm P.R.Brady tossed the following ingredients into the
ever-growing pot of cybersoup:

Here's one for the electrical/electronics gurus.

Our new Wayne-Dalton iDrive garage door opener operates its associated

light fitting via an IR beam: the opener proper installs right above the

door, while the light fitting can be mounted to any convenient outlet
within "view" of the opener.

The light operated correctly when it was first installed, but then
would sometimes switch on but not be able to be switched off except by
killing the power to that circuit -- and even then the light would
sometimes switch on and stay on as soon as power was restored.

I called Wayne-Dalton Customer Service. The rep. asked whether we had
fluorescent lights in the garage. I replied that we did but that the
problem existed even when the fluorescents (CF) were turned off. The
rep. then said, "We have found that fluorescent lights can interfere
with infra-red sensors even when the lights are turned off." I told
her I couldn't see how that could be, but there was no point in
arguing, because she was only reciting her official spiel.

They are going to send a new light unit and a new motor-control board
(mine is an older revision, it appears), but . . .

Please tell me that there's no way a switched-off fluorescent can
interfere with IR circuits.

I'm not sure I understand this phrase:

" operates its associated light fitting via an IR beam:"

I may be wandering down a byeway but are you saying that
- when you open the door, a light should turn on automatically?
- the 'switch' for this came with the door opening kit?
- the switch is controlled by infra-red from the main unit?
- That the light is a flourescent?

So the question might be whether the flourescent light is a suitable
load for this electronic switch, and not whether it interferes with an
IR beam?

When the door is operated, the light should come on, remain on for 5
min., then switch off again. The wall-mounted *wireless* control that
came with the whole set also has a separate button that is supposed to
operate the light, toggling it on and off -- but, again, the light is
controlled via the IR link from the opener proper: Wireless switch sends
RF signal to opener, which in turn sends IR signal to light fitting. So
the light fitting needs only a convenient outlet -- no control wires.
BTW, the IR sensor on the light fitting can be aimed fairly readily at
the opener proper.

I have used only a regular incandescent bulb in the opener-associated
light fitting: it will normally be on for only a few minutes at a time,
so the expense of a CF bulb would take years to recover. The fluorescent
lights in question are the CF ones in the original ceiling light sockets
-- but whether they are on or off makes no difference.

Perce