There are four people who work in our district’s technology office, and I"m the first to arrive at 6 am. Since I’m the first, I’m alone and sitting in my cubicle reading and responding to work orders, messing with you guys, etc. The motion sensor doesn’t register me, so it decides to turn the lights off. This happens every 10 minutes without interruption. It turns them off, I turn them on, it - off, me - on, ad infinitum. Now, you would think that the arrival of the other tech assistant at 7 am would solve the problem but, no, same bullshit. The data guy arrives next. That’s three of us sitting and working in three different cubicles, so that solves the problem, right? Nope!
Now to my point and question. When the lights go off, I have a very hard time getting them on. I often have to raise my arms and wave them wildly about or, on occasion, actually stand up and step out into main area. However - and this is what I simply can’t understand - if I just raise my arms and clap my hands loudly 2 or 3 times, the lights go on immediately. Why? It’s a MOTION sensor, not a sound sensor. What gives? Does it detect the shock waves from my clapping? Is it haunted? What?
I usually trigger those annoying motion sensors by raising my arms and waving them around. I bet when you clap you put your hand through one of its sensors.
Do the lights turn on if you clap your hands from a spot you know it can’t see you? Is it possible it also has a microphone and reacts to sound as well? Maybe just putting a radio next to it will keep the lights on.
I asked, but no one knows If so, I’d better watch what I say. LOL
Just had an idea. The next time it happens, I’ll put my hands under my desk and clap loudly. No way it could “see” that. If it reacts to the sound, then it must have a mic somewhere.
Never heard of a mic for an occupancy sensor. The other thing you could try is to make the motion of clapping your hands but “miss” by passing your hands in front/behind each other. I suspect that the motion you’re generating by clapping has a slightly different profile than just waving, possibly faster and more abrupt, and that difference is what trips the sensor.
My understanding on how these inexpensive motion-activated light switches work is they take an infrared “picture” of the area and if that “picture” changes, they consider it to be motion.
Now I put picture in quotes because it is much more a signal than a actual image. That is, it is not focused and cannot detect any specific shapes. Think more of one of those non-contact thermometers (the one with the laser pointer built-in), except it is not focused on a spot like the thermometer is. So, what it is detecting is a temperature change in the surroundings.
Perhaps when you are waving your hands wildly, you are moving them so quickly it doesn’t react because you are moving them too quickly for the temperature change to register, but when you clap, you hold your arms still long enough to get them noticed.
Think of it more of a temperature detector than a motion detector. Just raise your arms and hold them still until the lights turn on again.
The ones that I have seen use PIR (passive infra-red) and ultrasound. The PIR portion looks for a change in infra-red light. For the sound portion, they aren’t listening to what you say, they just have some very simple circuitry to detect the presence of absence of sound waves. So if you want to say naughty stuff in the office, you don’t have to worry about your light switch ratting you out.
Designs vary, but look for little grates either on the switch or on a sensor mounted on the ceiling.
Hopefully you can see this image:
Ceiling sensor:
If you can’t see these then do a google image search for “PIR ultrasonic light switch”.
This has gotten very interesting! Nope, ours look just like the picture but without the grills. So, the posters who said it probably isn’t the clapping sound that is doing the job have to be right, and I thank you for helping me verify that. I’ll research a motion toy.
One curious angle of this is: Do I infer correctly from the OP that you need more motion to retrigger the lights than what you needed to switch them on on first entering the office?
Have you tried running a small fan, or placing a drinking bird near the motion detector?
Well, when I walk into the office, it turns on the lights, but not until I’ve taken 2 or 3 strides. I guess it isn’t very sensitive for a motion sensor.
I might bring a colored t-shirt to work with me, and try waving it around (probably over my head) like a matador when TPTB decide you’re too sedentary to merit artificial illumination
