Strange LED Security light behaviour

[mike2016]

Couldn't find anything on google about this so thought I'd try here....

I used to have two cheap solar led lights on my shed outside and whenever a bus was parked on the road opposite they would go off despite no line of sight to the PIR. I've since retired them and have a reputable version out from covering a small nook there. A wierd thing happens when 1 particular car passes by, the light turns on, but it doesn't do this for any other car and there is a good 9-10 meter distance. I have to stand within 3-4 meters to set it off myself. 

So, question begs what sort of EMI or interference could cause this? Just curious! Thanks. 

[Gone West]

3 hours ago, mike2016 said:

So, question begs what sort of EMI or interference could cause this?

We have a similar problem. Our sensor is above our front door and out of line of sight of car headlamps. When a tractor goes past with high level lights, which are out of line of sight of the sensor, the lights come on. I traced it in the end to a reflection off a front window and onto the sensor.

[AliG]

We used to have a car and when we parked it close to a supermarket the remote control to unlock it would not work. The only thing I could see that might affect it was a light tube along the edge of the store, but I don''t know why it would affect the remote which worked on radio.

 

Maybe the car passing by has night vision and this could affect the PIR if it sends out infra red?

 

As we are talking about weird light behaviour, we haven PIR light near to the boiler flue and the steam sets it off all the time. I am about to replace it with a microwave one.

[mike2016]

Cheers - might be a reflection from the headlights of that particular car so! My grass sets off the rear PIR if I can't get it cut short enough for the winter whenever there is a heavy wind blowing. Might look into that microwave one if that is outdoor rated? Thanks all.