Help needed... Toggle switch for LED lighting circuit

[Chris]

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.

Lee

Hi, Lee. You're going to have some difficulty with switch bounce, and
also with people changing their minds, more than one person going down
the stairs, and lots of other things. It's not going to be pretty when
Grandma steps on the first stair, and your gizmo turns itself off.

It might be better for you to set this up with a timer, so the LEDs
will go on when someone steps on either step, delays on for a minute or
two, and then goes out. Things are complicated a little by the total
current you're switching (about an amp).

There are many kits available that will give you an intermediate time
delay. The Velleman K2579 is a good choice -- it will give you a
consistent time delay of 0 to 15 minutes. It's based on the venerable
LM555, and is a proven circuit with a circuit board and easy
instructions. Once you build the kit, you can just wire your two
pressure switches in parallel between the SW1 and the - of the power
supply, where either one could initiate the delay. The 555 drives a
relay that can switch 2 amps. Check it out before you buy:

http://www.velleman.be/ot/en/product/view/?id=8996

It's available from many hobbyist sources for around $15. And if the
trip to the store or the minimal cost doesn't appeal, just make one
yourself out of components from your junkbox.

Good luck
Chris

 

[John Fields]

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.

 

[JazzMan]

Probably not a bad idea to use an off timer too incase the
presure plate gets missed on exit, otherwise the next user
will turn the lights off when they hit the plate. Or,
if you have a metal hand rail you could use a touch sensor
in the rail to trigger the lights, or use an infrared motion
sensor as is to trigger the lights. The motion sensor can
be hidden in the tread face board or in an overhead fixture.

JazzMan
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[ehsjr]

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.

Lee

Dump the toggle idea and use PIR to sense when someone
is on the staircase. Toggle is too easily defeated by
human unpredictability.

Ed

 

[Bob Monsen]

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

 

[Rich Grise]

Probably not a bad idea to use an off timer too incase the
presure plate gets missed on exit, otherwise the next user
will turn the lights off when they hit the plate. Or,
if you have a metal hand rail you could use a touch sensor
in the rail to trigger the lights, or use an infrared motion
sensor as is to trigger the lights. The motion sensor can
be hidden in the tread face board or in an overhead fixture.

Or one of those PIR yard lights - I think the turn-off delay is adjustable.

Or, just turn it on whenever somebody steps on either of the mats, and
leave it on for, say, 3-5x the time it normally takes to go up or down
the stairs.

Or, just leave the suckers on whenever it's dark inside. (like
those photoelectric night lights.)

Good Luck!
Rich

 

[cbm5]

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.

Lee

Your idea does not account for multiple people on the stairs.

 

[Chris]

Chris, you're an absolute star!

A timer setup was my first option in mind, but I thought it would be neater
to have the light switced off by the user too, I was thinking that there
must be some way of crating a toggle circuit that could only be switched
on/off by the opposite switch... But hey, the timer idea is probably more
functional and easier to implement.
Also those Velleman kits are great and well within my scope of understanding
)

Thanks again
Lee

Hi, Lee. You've got quite a few good ideas from other posts. If you
decide to go with the Velleman kit, though, you might just want to make
a small addition when you install the circuit. Looking at the manual
for the kit, it seems the switch is just tied directly to the 555 TRIG
pin (turns on the 555 when grounded), with only a 1K pullup resistor on
board. If you actually install that circuit, electrical noise may
cause false triggering of the 555, leading to "nuisance ONs".

You can pretty much get rid of that by adding two components, commonly
available at Radio Shack or any hobbyist outlet, by tack-soldering them
on the circuit board as shown (view in fixed font or M$ Notepad):

|
| VCC
| +
| | Internal
| .-. 1K Ohm
| | | Pullup
| | |
| 22 Ohm SW1 '-'
| FSW1 FSW2 ___ | To 555
| .------o-----------|___|-o-------o--o---o-> TRIG
| | | | Pin
| | | --- .---o--o----.
| \ o \ o ,01uF --- | |
| \ \ | | |
| \. \. .------------o---' ===
| o o | GND
| | | |
| | | |
| '------o----'
|
(created by AACircuit v1.28.5 beta 02/06/05 www.tech-chat.de)

The .01uF cap and the 22 ohm resistor together will help prevent false
triggering, and the 22 ohm series resistor will also help extend the
life of the floorswitches FSW1 and FSW2.

Good luck with your project. Have fun!
Chris

 

[nibbles]

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.

Lee

 

[nibbles]

Chris, you're an absolute star!

A timer setup was my first option in mind, but I thought it would be neater
to have the light switced off by the user too, I was thinking that there
must be some way of crating a toggle circuit that could only be switched
on/off by the opposite switch... But hey, the timer idea is probably more
functional and easier to implement.
Also those Velleman kits are great and well within my scope of understanding
)

Thanks again
Lee

 

[nibbles]

Thanks everyone for all the ideas, theres a few that I hadn't considered
there - I especially like the idea of the touch sensor in the hand rail as I
will be fitting a stainless steel rail soon.
Any ideas on setting such a system up, coupled with the off timer?

 

[Jasen Betts]

Steve Gonedes explained on 1/06/2013 :

That post is 7 years old now so he has fallen down the dark stairs.
:-(
Anyway he wanted a toggle circuit to switch either way with the press
of the top or bottom switches not a simple toogle switch. :-Z

SPDT is a fairly simple switch, a bedlamp switch won't do it,
but many others will.