Hi all,
I'm trying to create an LED lighting system for my staircase - which will
have a row of 15 LEDs under each tread bullnose, that are switched on/off by
pressure mats located at both top and bottom of the staircase.
I intend to wire up the LEDs as 65 parallel arrays of 3 LEDs operating on
12v @15ma/3.5v using a 100 ohm resistor for each (195 in total so lots of
soldering to be done!).
The above was calculated using the this online calculator
http://led.linear1.org/led.wiz so if my description isn't clear, pop them
details into the calc' for a diagram.
What I need help with is a simple(ish) diagram to operate the toggle
function as mentioned above, eg; Switch on when someone steps on the bottom
pad and off when they step on the top pad - or vice-versa.
Any suggestions would be greatly appreciated.
Do you have the pressure mats already? If not, a cheaper alternative might
be a sharp IR sensor, like a GP2D12. Mount it facing across the step,
and you'll be able to get a voltage pulse when somebody steps on the stair.
The timer idea some people have been suggesting is nice, except that if
people decide to sit on the steps for any length of time, the lights will
go out. Also, the LEDs on the top steps will be visible for people on the
lower steps unless you shield them somehow.
I have a dark hallway leading to a bathroom and a coat closet. The hallway
has a light, but there is no switch for it; it uses a twist switch on the
lamp itself. So, in order to find the bathroom at night, you had to feel
around to the lamp. Sadly, the lamp had a glass shield that popped out if
you pushed on it. So, the only real solution was to leave the light on all
the time, which I disliked for various reasons. So, I used one of those IR
sensors to sense when somebody was coming up the hallway, so I could turn
on the light for 5 minutes, on a timer. There are several issues I have
with the current circuit, though. There is no way to simply turn on the
light and leave it on (no external switch). There is no way to adjust the
length of time (without reprogramming the microcontroller that is used to
time the delay). Also, the light flashes on unexpectedly for newcomers,
which can be startling, since it is hard to see, and if you happen to be
looking in the wrong direction, can be blinding. FYI. These are all easy
to solve problems, but I haven't gotten around to fixing them yet (it has
been a couple of years now... I post this as food for thought.
--
Regards,
Bob Monsen
I know not with what weapons World War III will be fought, but World
War IV will be fought with sticks and stones.
Albert Einstein
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