Hello all! I'm need a way to sense when a piece of equipment is powered on. Essentially, I'm needing to turn a servo motor 180 degrees when machinery is turned on (Table Saw, Belt Sander, Cnc Machine, etc) and turn the servo back to 0 when turned off. It has to be something that is non invasive as I don't want to cut into the power cables to separate wires. Any ideas? Thanks much!
Absolutely sure? Then use a microphone (piezo?) to listen to the device, or an LDR on its power lamp...
SCNR
Yeah without tapping in to power I guess for things like a sander, table saw... maybe sound will be the best way?
Won't a microphone pick up other machines? It is pretty loud at my shop where I'm needing these. I'm wanting to make blast gates (if that helps)
And, not all of them have power lamps.
Build a box with a plug on one end and a socket on the other. Put a sensor in the box with a lead going back to the computer. Get any of 100's of AC INPUT SENSE MODULES and wire across the Hot & Return.
OPTO-22 has a full line of modules
`
AC main detector module
Try googling "ac input sense module arduino"
They're less than $2 USD on eBay
The mike should detect vibrations (structure-borne sound), not noise in the air.
Would a hall effect sensor work?
It works when applied to a single power wire, not with a power cable.
Which is why I suggested the interface box. I have these on my Dust Collector and compressor as neither are convenient to reach. I just build out a single J box with a switch and put plug & socket on SJ stranded cables. Then I can turn off & on with a normal switch and no hacking. Replace the switch with a sensor and problem is solved.
Do you by chance have a photo of the box?
It's a standard box you find at a home center. A cord and an outlet. Knock a hole in the side to route the cable to the computer. Use a larger box if needed. They're only a few bucks.
You're making this lots more complex than it needs to be. $6.38 @ homedepot
Plus everything is UL approved. You can put different outlets on. I have a 220V 20A twist lock on the DC. You can build them with or without the outlet. You can just run the cord thru the box with your tap on the side. You can get modules that give you an on OFF or you can measure the voltage or you can CONTROL the device with a +5 signal from the arduino. Mount one of THESE in the box an you can control the world!
Machine Learning. Infared camera. Raspberry Pi. KNN (K Nearest Known Neighbour) or TensorFlow would work
Just put an overhead Infared camera in the shop. Map the camera view area when all the devices are off to get a base line cold room machine learning trained model. Next, do a few training models when each machine is on. Now one can code to detect heat blooms.
Is it correct that the ground and hot wires cancel each other out?
Hot & neutral have same current in opposite polarity. ammeter can't distinguish and reads zero.
Thanks! I know how to do some light coding with arduino, but not much about electricity