AS312 Mini Pyro-elektrische PIR Menselijke Sensor Module PIR Infrarood IR Sensor Body Handleiding Motion Infrarood IR Detector 3 stks

Not tried it in a circuit yet. Don’t try and put up to 12v into it. The data sheet, for an AS312, clearly says max value of 3.6v.

Wired one into circuit At 4v dc did not work dead used another at 3v gave up put a switch in load of rubbish n on t buy any more

My original intention was to use Microwave radar sensors in my application - but that ran into problems (see * below). So, I ordered some of these and they work well - they have a good range and - provided you ignore the specs and only run them on 3.3 volts (they cook if you go up much higher) taken from my MCU board they work very well.There is one issue I encountered - which was easily overcome. My project uses a NODE MCU ESP-12F microcontroller which has built in Wi-Fi. Originally, I mounted the sensor back-to-back with the MCU - meaning they were just few mm apart inside a small project box. In that configuration the sensor was giving me almost continual false triggers. I added a second small box and put the sensor in that - with just using Dupont cables for the 3-wire power plus signal interconnection between boxes. With the MCU and the sensor now about 60mm apart the problem went away, and the project works exactly as it should.* Using microwave radar sensors: Those devices are incredibly sensitive and can be totally enclosed in a plastic box which makes them visually undetectable. BUT, their incredible sensitivity is also a problem in some applications because they can "see" moevement through stud (and possibly block) walls! I wanted an entranceway sensor to turn on lights so that a person entering a building could see their way to the main space. That worked fine, but the radar sensor also triggered when there was movement in the main space - meaning that the entranceway lights stayed on all the time. As a general intruder alarm sensor those sensors would be excellent - however for localised detection these little PIR sensors are a better match.

Putting 9volts into these warms them, then they melt. Rubbish dont buy