Re: Stepped lighting.


<bill.sloman@xxxxxxxx> wrote in message
news:1175331105.085268.136430@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Mar 31, 4:15 am, "John Barrett" <ke5c...@xxxxxxxxxxx> wrote:
<bill.slo...@xxxxxxxx> wrote in message

news:1175296706.003283.54200@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx





On Mar 30, 11:45 pm, martin griffith <mart_in_medina@xxxxxxxx> wrote:
On Fri, 30 Mar 2007 21:30:20 GMT, in sci.electronics.design "John

Barrett" <ke5c...@xxxxxxxxxxx> wrote:

"I.P.off10" <La casa d'ayer ria> wrote in message
news:IZSdnb47VcO17JDbnZ2dnUVZ8qugnZ2d@xxxxxxxxxxxxxxx
a request for a circuit/layout for light switching that will turn on

low level lights 2 or 3 steps in front & 1 behind as a person walks

along a corridor or up/down stairs. Component list & values would
also

be required if possible. My thanks for your consideration.

--------------= Posted using GrabIt =----------------
------= Binary Usenet downloading made easy =---------
-= Get GrabIt for free fromhttp://www.shemes.com/=-

Option 1.. low power laser range finder at one end of the area to be
covered, with microcontroller to read the range and control the
lights
(low
level ?? perhaps LED ??) .. this setup would be able to determine
direction
of travel and do the 1 behind and 2 in front requested.. practically
speaking, this setup would be limited to 4-6 lights due to cabling
considerations

Option 2.. ultrasonic or laser sensor at each light -- with wiring
between
the lights to allow one light's trigger circuit to also enable the
adjacent
lights -- this could be done without a microcontroller by activating
2
in
front and 2 behind, or with a microcontroller at each light.. this
system
can be modular... extensible to any length of light string with no
more
than
4-8 wires between each module -- CAT5 cable and connectors would be
optimal.

if you are talking more of a strip light than a series of wide angle
point
sources... the same techiques can be applied with the lights in
banks,
or
with more extensive microcontroller control to actually turn on
individual
closely spaced sources in sequence.

You are welcome to contact me via email if any of these options
address
your
problem.

hmm, force sensing resistor, 5 or so diodes, couple of logic gates,
and of course a 555, just to annoy Bill Sloman

I'm more anoyed that you didn't notice that this is actually a job for
an off-the-shelf person sensing circuit, that you can buy in any
lighting shop.

IIRR the fittings contain an infra-red sensor which picks up human
body warmth - spread a couple of them along the corridor and the job
is done. No need for logic or a 555.

--
Bill Sloman, Nijmegen

ummm really ?? they make on that will turn on several banks at a time ??
for
instance, if you have 8 light sources , it will turn on 123, then 234,
then
345, etc as you walk down the hall ?? and conversly 876, 765, 654, etc as
you walk the other way ?? always with 2 banks on in front of you ??
Person
sensors that I'm aware of only control one circuit.

I was envisioning something more along the lines of a strip that could be
installed along the base molding of a hall way, powered by a single wall
wart... and if the OP is interested in the modular approach, one that
could
daisy-chain for a hallway of any length.. say in 2-4 ft sections.

An IR sensor would certainly be a viable technique also.. but some logic
is
going to be needed for the "feed forward" to turn on lights ahead of the
person walking no matter which way they are walking -- logic gates or an
8
pin PIC/AVR -- doesnt really matter much.... If I put some more thought
into
it -- I could probably figure out a way to do it with no more than 8
wires
between stations and discreet logic only -- or 4 wires (2 power, 2
differential data) and a MCU...

dozens of ways to solve this one -- need some more info to pick the one
that
best fits the OPs intentions.

The logic is a red herring. The OP just wants to walk in a pool of
light, and having the lights stay on few feet behind him (which he
doesn't need) is a cheap price to pay for having them come on a few
feet in front of him, and greatly simplifies the task.

It is always as well to keep in mind that you want to provide what the
customer needs, rather than what they think they want.

--
Bill Sloman, Nijmegen


hmmmm you are a mind reader ?? you can figure out the complete details of
what the customer wants based on an incomplete description ?? The original
post didnt specify anything more than "low level lighting" -- thats easy --
LEDs.... what was not specified was how many LEDs, what spacing, total
length of the LED array, desired form of the lighting array -- the circuitry
in general is simple enough, but choosing a specific implementation to match
the target hardware requires a bit more information than we have gotten so
far.


.

Relevant Pages

  • Re: Stepped lighting.
    ... with microcontroller to read the range and control the lights ... person walking no matter which way they are walking -- logic gates or an 8 ...
    (sci.electronics.design)
  • Re: Stepped lighting.
    ... this setup would be limited to 4-6 lights due to cabling ... lights -- this could be done without a microcontroller by activating ... customer needs, rather than what they think they want. ... what was not specified was how many LEDs, what spacing, total ...
    (sci.electronics.design)
  • Re: Stepped lighting.
    ... with microcontroller to read the range and control the lights (low ... this setup would be limited to 4-6 lights due to cabling ...
    (sci.electronics.design)
  • Re: Stepped lighting.
    ... with microcontroller to read the range and control the lights ... this setup would be limited to 4-6 lights due to cabling ...
    (sci.electronics.design)
  • Grow-Tron, For Sale!
    ... Uses less power than two 100W incandescent bulbs with the ... The idea here is still to fit the lights into the tank. ... So I'm thinking some hundreds of LEDs would go into the tank. ... Reds again should be all over. ...
    (rec.gardens)