Re: infrared wall to detect an object

Hernán Sánchez wrote:

Hi.

For a project that I'm building, I need an object detector that signals
when something "cross" the virtual wall of light.

I create a virtual wall using a laser and two mirrors (one in front the
other). The laser goes to the front mirror, it reflects the light back
to the other mirror that is behind the laser, and it reflects back the
light and so on. An the end, a photorresistor sense the laser light.
When an object cross thru the light, the photorresistor change and a
comparator signals that something is passing thru the virtual wall.

The problem is the photorresistor that it is sensible to natural light
and of course the laser... it is dangerous for the eyes (an accident
can happen). Another problem is with the mirrors, they need to be
complete aligned to each other.

I want to change it to infrared light and a IR detector.. like those
used in remote controls. But I need some IR leds with a small
apperture to create a virtual wall.

Do anyone has some ideas, facts, experiences, suggestions and so on
about what to do ? Is it a good idea ? Any led reference for it ?

Thanks

Hernán Sánchez
Medellín, Colombia

Hoyt Engineering has developed just such a presence sensor which is not
yet available for public sale. What I am able to disclose is that this
sensor rejects noise orders of magnitude greater than the received
signal, including noise transmitted by other such sensors. Response time
is 20mS or less and total power dissipation is around 1 mA for a sensing
range of 1-2 meters. Component cost is less than 5 USD.

I would be happy to provide you a solution in return for your honest
application feedback. Please e-mail me directly to discuss further.

--

Steve Hoyt
Hoyt Engineering
http://www.HoytEngineering.com

.

Relevant Pages

  • Re: infrared wall to detect an object
    ... I create a virtual wall using a laser and two mirrors (one in front the ... I want to change it to infrared light and a IR detector.. ...
    (comp.arch.embedded)
  • infrared wall to detect an object
    ... when something "cross" the virtual wall of light. ... I create a virtual wall using a laser and two mirrors (one in front the ...
    (comp.arch.embedded)
  • Re: Fabry-Perot question
    ... > some signals, but they are way too small, what reason could that have? ... > We do see signals, FSR as expected, fairly easy. ... this isn't as critical as for laser resonator mirrors in the ...
    (sci.optics)
  • Re: infrared wall to detect an object
    ... For a project that I'm building, I need an object detector that signals ... when something "cross" the virtual wall of light. ...
    (comp.arch.embedded)