human detector

hi friends,

I don’t know if I can say me mean correctly or not, but I need for a kind of circuit or sensor that could detect human presence ,in other words a circuit or sensor that becomes active when a human is near it ,it should be sensitive to humam or animals only not to other things

I thought about motion detector sensors but what I need has to be active when a human is near it even if he/she does not do any motion

Sorry but it is very important for me to solve this problem so any help would be very appreciated

hi

hi
u should search for some laser transmitter & reciever circuits
they r simple and efficient

try hooking up a piece of wire to the input of a CMOS inverter gate, or a MOSFET, and putting an LED on the output, and seeing what happens when you wave your hand near it.

not sure how many other things it would be sensitive to though.

another option would be a PIR detector that would detect body heat.

epilot said:

hi friends,

I don’t know if I can say me mean correctly or not, but I need for a kind of circuit or sensor that could detect human presence ,in other words a circuit or sensor that becomes active when a human is near it ,it should be sensitive to humam or animals only not to other things

I thought about motion detector sensors but what I need has to be active when a human is near it even if he/she does not do any motion

Sorry but it is very important for me to solve this problem so any help would be very appreciated

Click to expand...

an IR detector (kept at a height) will do ur job , u need to adjust it's sensitivity .

epilot said:

hi friends,

I don’t know if I can say me mean correctly or not, but I need for a kind of circuit or sensor that could detect human presence ,in other words a circuit or sensor that becomes active when a human is near it ,it should be sensitive to humam or animals only not to other things

I thought about motion detector sensors but what I need has to be active when a human is near it even if he/she does not do any motion

Sorry but it is very important for me to solve this problem so any help would be very appreciated

Click to expand...

search for Pyroelectric sensor. Works on IR field (heat) and not capacitive coupling.

Even a pyroelectric sensor won't have a lot of luck unless the conditions are well controlled. A sunbeam coming through a window can be warmer than a person. A person wearing a jacket may be little warmer than, or even colder than, the room. A pyro sensor also only has one reading (unless it's a camera) so you either have to focus it as a beam on one area or spread it out over a larger area in which case the temp is averaged out and that may make body heat less detectable since the field of view may see 40% body and 60% background.

The IR motion detectors are generally the best solution to date, but they do require the target to be moving. Being able to reliably detect a person who is not moving has no practical solution I know of. A camera, preferrably thermal camera, with machine vision to try to identify a person's outline can do that but it's generally not practical. Not alltogether reliable either since a person can change their shape easily.

What do you actually need to do? I'd think that the requirements can be changed and still do the job.

Get a dog. They can detect that a person is present even when you can't.

How much range do you need? A couple feet? 50 feet?

Russlk said:

Get a dog. They can detect that a person is present even when you can't.

Click to expand...

You could also try a mosquito - very sensitive to human presence. All you need then is a microphone and a circuit that is tuned to the specific mosquito 'whine', which triggers your application of person sensing.
Klaus

hi friends and thanks so much for your comments,

i want to do a project for a house, really for electrical devices(lights, fans,radio..)the owner would likes his devices be active when he is at the room or sitting room and become inactivewhen he leaves the room.
i thought about motion switchs but such as i know they are good for garages and passageways where a person is traveling thrugh them,
they are not good for a 20x10ft room where a human might be sitting down and listening a song or studying..
IR sensors and PIR sensors are not a good choice for this job i think,
i wish PIR's were as only human or animal detectors but suppose a cold day and you need to to turn on your heater,

please let me know if anyone have seens any special ready device for rooms such as a sitting room?

hehe, o yes i can rent some of mosquitos and a honeyed IR detector sensor, i tie them with a cotton and get it with my handd and when i want to go out i let them go and they will find their target,lol :roll:

epilot said:

please let me know if anyone have seens any special ready device for rooms such as a sitting room?

hehe, o yes i can rent some of mosquitos and a honeyed IR detector sensor, i tie them with a cotton and get it with my handd and when i want to go out i let them go and they will find their target,lol :roll:

Click to expand...

this is a concept from smart homes.
the persons carry low range rfid tags , so that the reader in the room can detect his(er) personal settings .and adjsu the lighting and so on..

akg said:

epilot said:

please let me know if anyone have seens any special ready device for rooms such as a sitting room?

hehe, o yes i can rent some of mosquitos and a honeyed IR detector sensor, i tie them with a cotton and get it with my handd and when i want to go out i let them go and they will find their target,lol :roll:

Click to expand...

this is a concept from smart homes.
the persons carry low range rfid tags , so that the reader in the room can detect his(er) personal settings .and adjsu the lighting and so on..

Click to expand...

what is a rfid? do you mean RF ID (a radio freq identification?)

it is very cool idea a special lable for every person,
but will happens if 2 persons come to home?2 lable and then?

do you have any link for more info pplease?


P.s do you think that device will turn off the devices when no one is in the home?

Here's an overview of RFID tags:

https://cq.cx/prox.pl

yes i mean RF ID

it is very cool idea a special lable for every person,
but will happens if 2 persons come to home?2 lable and then?

do you have any link for more info pplease?


P.s do you think that device will turn off the devices when no one is in the home?

Click to expand...

these things , and how should be the action under different conditions are to be done in communication protocol and h/w+s/w

so it seems i have no way to do this project!?

i am in doubt why there is no ready device for sitting rooms?
anyway electronics can solve alot of problems,and this is a small problem so?

.. it seems i have no way to do this project!?

Click to expand...

no one can say like that..
there should be some method and solution.
actualy some time ago, i was also thinking something like that,but couldn't find something simple .

the thing close to what i reqd was the rfid, but that was not simple

Just an idea.

Two photocells and some logic circuit (or MCU) could do the job. One photocell can be placed just outside and the other just inside the door to the room.
When the outside photocell is activated first and the inside photocell next, then someone enters the room. Counter is incremented.
Conversely, when the inside photocell is activated first, then someone leaves the room: counter decremented.
If the counter is zero, switch off all appliances in the room. It it is nonzero switch them on.

However, there are restrictions to use:
People must always enter the room one by one, and leave one by one.
To simplify the logic circuit people should not stop and turn back in the door.
Owner should never quit through the window. (Hope the room is on 15th floor...).
Etc.
A reset button outside the room (which resets the counter to zero) always comes handy, just in case the above rules are violated...

When there is more than one door to the room, it makes more cabling work to connect all photocells to the counter logic.