Question about AC infrared motion sensor

Hi everyone, I need a little help with a project.

I have a an AC infrared motion sensor, it's powered by 220V AC, it has a single signal cable that also outputs 220V AC, the plan is to use that signal to activate other modules an functions.

That's the idea, but I'm still wondering how to turn that 220V signal into a signal that can be read as a digital input by an Arduino Uno digital pin (I only need HIGH and LOW values), an how to conect it to the Arduino.
Is this possible? Can I use a transformer and a rectifier?
Thanks for reading.

The AC motion sensors I know use a capacitive supply that is directly connected to mains power.
Dangerous, unless you switch some power supply on/off with the sensor.
A 5volt cellphone charger could work.

I would forget about it, and use a $2 5volt PIR sensor from ebay.
Leo..

The problem is that using a less porwerful sensor, mea, my group and I are building a prototype for a system that has to work in thens that the project won't work Andes near the desertic zones, is solar powered because there's no other way to power it there, the sensor has to endure heavy conditions, the Arduino will be protected, but the sensor has to be outside. We don't think a $2 5volt pir sensor will be capable of surviving the extreme conditions.

Are we going to help you with the assumption that your premises about how your pir sensor works, and possibly after giving you a solution it doesn't work because you were wrong starting off? How confident are you in your conclusion? Have a datasheet available for those of us who can't trust your claims?

  1. the supply voltage doesn't say much or anything about the "power" of a sensor.
  2. you didn't specify working conditions, not even the range it's supposed to work at, or what kind of objects it's to detect.
  3. I don't think your basic off-the-shelf PIR detector is going to be sufficiently ruggedised for you, too.
    4( when using solar it's generally more efficient to stick to DC, rather than convert to AC.
    With the conditions you describe, you're going to need a good enclosure for your sensor, any sensor. When that's taken care of, 1) and 2) determine whether the $2 sensor is suitable. Fair chance the 220V AC sensor is also not suitable for that reason (by the way, the sensor may be switching 220V and be powered by 220V, but does it internally also work on 220V AC or a lot lower voltage DC? I expect the latter!).

Well, finally in worked, the sensor is a 0.48W 200 V AC infrared sensor, the voltage of the signal was lowered and rectified with a cellphone charger to 5V DC, the sensor detects little movements at 12 mts in a 180° angle sensor, so it has behaved pretty well, its function will be to detect pumas near cattle and set off different signals to keep the pumas away. Thank you for your help :smiley:

Cattle and pumas? You were worried about PIR sensor in 'extreme conditions'?
Put a $2-5 PIR sensor alongside cattle and my money goes to the former on 'who can survive extreme conditions'.

for llamas is easy to survive in the Chilean Andes near Atacama desert, the sensor selected is the same that has worked in other projects in the zone, the idea is a portable system because the llamas don´t stay in the same place always, because there are not farms in a conventional way, “Arrieros”(which is how we call here people who work like this) have little packs of animals, llamas mostly, and they take their animals to eat the new grass in the Andes during specific seasons.
During these periods, during day they let the animals free, because there’s not mayor threat but during night they keep their animals in “pircas” which are little corrals made by 1 meter high rock fences, they circle an area around 100 m2, they are not big, arrieros don’t keep their animal in the same pirca every night, that’s why the system has to be portable, there’s plenty of sun there, we have the batteries and the portable solar panels, to power this thing, which consists in a series of posts that can be easily installed and removed, they work independently, they weight less than 1kg each, so the whole system can be easily transported by horse or by llama which is what we call cattle.

Maxbotix makes some very nice ultrasonic sensors that may be a good fit with your project.