Proximity sensor

Hello !
I'm not very good at electronic and I need you to help me. I got a projector on which I disassemble the proximity sensor for the purpose of my project home alarm.
Here are the pictures of the sensors in question:



Can you tell me how I should manage to connect on my Arduino? Must I use an adoptator or anything to connect on sector ? In the best case, it is possible to connect directly to the card?
Note: The color code my threads is that of France (I do not know if that changes anything).

It looks like a PIR.
What is it doing on a projector?

(En francais, si tu veux)

Dès que quelqu'un passait devant, le projecteur s'allumait. Le model, c'est "RP500" 230V 50Hz ; MAX 500W.

Ah!
OK. "Projector" in English usually means something like a video or movie projector.
This is more of a security light.
Unless it has a convenient relay, or obvious logic level outputs, you're going to find a schematic.

The colors of your wires are supposed to be the same all over Europe, but for sure are in Germany and BeNeLux.
Brown is Live, Blue is Neutral, Black is switched Live.
Your sensor switches 230 V AC to your floodlight "light projector".
You cannot use that to directly interface to your Arduino.

There are 2 PCB's visible in your pictures.
The second PCB, which is only visible in the 3rd. picture might have a relay (relais) on the invisible side.
You can probably alter the PCB so that that relay will not be connected to the 230 volts DC anymore.
Then you can use those contacts to switch your Arduino.
This still will require you to power the PIR sensor from 230 V, and i'm hesitating to advise you to do so (because you have to ask this question).

The pics also show there are 3 wires (in 1 flatcable) between the 2 PCB's.
It might be so that the second PCB works on 5 volts or can be changed to do so.
But to know this for sure, your webcam pics aren't clear enough to tell us anything more.

Thanks for answers :slight_smile:
I do not know how to put ... Here are two new photos of the PCB. If it still need a better quality I'll go get my camera.

What's written on the chip and on the "transistor" ?

Chip:
OM3
HA17324

Is this a transistor :
If yes, I'm not sure but it must be:
S9994
331

I surrounded colored parts of the circuit which was connected to the wire color surrounded:

crocoscore:
Is this a transistor :

That is what i meant by "transistor", as that is the most common part in that (TO92) casing but it really can be anything that requires 3 wires.
The number S9994 on it doesn't turn up anything identifying it so i don't know what it is or is supposed to do.
Somehow i missed the fact that there are 2 of these parts on the PCB.
Do both of them have the same written on it ?

The HA17324 is a quad opamp (an amplifier), which makes sense.

Oh ok, I note that !
There is same part of the composant name erased on the 2 transistor (I think, but I'm not sure, that they are same)... I could be "S9...14" or "SW14" or "S9914". It realy difficult to read, even with wen.

I forgot to say to you that there is written "rs8w2" on the 2 PCB.

MAS3:
There are 2 PCB's visible in your pictures.
The second PCB, which is only visible in the 3rd. picture might have a relay (relais) on the invisible side.
You can probably alter the PCB so that that relay will not be connected to the 230 volts DC anymore.
Then you can use those contacts to switch your Arduino.
This still will require you to power the PIR sensor from 230 V, and i'm hesitating to advise you to do so (because you have to ask this question).

Having for the moment no alternative, is there a risk if I branch (fiddling) sensor on my arduino board via the 3-wire without using external power?

I finally forced a bit and I cut the wires. These new photos to learn more:


I hope that someone can help me now :slight_smile:

Ok, here is somethig you can do.
But first i'll issue a warning.
Keep in mind that you are working with 230 volts, and this can have serious consequences if you make an error.
That includes personal injury.
So really, take care !

Having said that, i just looked up that relay in there.
It is a jzc-22f-s-a, and you'll find the footprint of that relay in that link.
Based on that and your pictures, i did a little editing of one of those pics.
See attached pic.
Cut at the red line, and cut at least 3 mm away from the part you marked in the brown color.
Remove the capacitor (the brown cushion like part between the black, blue and brown wire, the smaller one).
The part left from the red line and your black marked pins are the switch of the relay.
Check again to see there is no connetion left to the 230 volts (either live or neutral and don't think "neutral" means safe) to these black and left from red solder points.

Once you are sure this is really disconnected, you can connect some wires to those points and use that as a contact for whatever you want to do with it.

After soldering, consider plasticspray to cover the soldering points and the just cut copper in order to get some extra protection.