This is probably a niche solution to the problem, but for people who already have some home automation, it could be pretty cost-effective.
I wanted the dust extractor to trigger as soon as the saw turns on, and turn off after about 5 seconds.
This is easily done with a smart plug that can detect power running through it, but my saw is on a 32A plug, and they don't make smart switches for those
There are off the shelf solutions for monitoring either via wiring your machine through the device, or through a CT clamp - Sonoff POW or Shelly EM for example.
I was worried about the ones that 'intercept' power to the machine, on startup the current spikes to about 100A, I don't think these things were designed for induction motors.
The ones with a CT clamp still need to be wired into your mains box, I'm guessing in order to constantly read the grid voltage to accurately calculate the power consumed - they're used for monitoring power consumption, so that makes sense.
I don't really need an accurate reading, I just need to know if the thing is on, so I thought about vibration sensors, movement sensors that would look at the blade from underneath, all sorts of things, as I couldn't find an off the shelf solution with a CT clamp that doesn't need to be wired into the mains box, My saw isn't near the box and I wouldn't trust myself wiring it in, so I'd need a sparky as well and costs add up.
Then I came across this video:
It explains how to create your own current sensor that integrates into Home Assistant.
It sends the consumed power to home assistant, where I've set up an automation to turn on the dust extractor (which is on a smart plug), as soon as there is power on that CT clamp.
I've not calibrated it very well so I've set mine to turn on if the power is above 300 watts, I didn't bother dialing it in, as I don't need to know the consumption, just that it's on.
You need three things:
You need some basic soldering skills to solder some pins, but other than that, it's just some configuration in Home Assistant.
The video I linked earlier really helped, along with this one, as I've had no experience with ESP Home. I pretty much just copied the config from the first video, except I've reduced the reporting interval to half a second, instead of the default 5. I then excluded saving history for that device in Home Assistant so that it doesn't eat up storage.
The only problem I've got is that it takes around 30 minutes for the board to connect to WiFi, it should only be a few seconds.
From what I've read, the board itself could be defective, so I got in touch with the seller, but once it connects, it's solid, so not the end of the world for now.
The entire thing is tiny enough to not get in the way, I just need to build a case for it.
The earlier mentioned smart plug for the extractor is pictured below, along with a tactically placed clamp on the 'on' switch.
I wanted the dust extractor to trigger as soon as the saw turns on, and turn off after about 5 seconds.
This is easily done with a smart plug that can detect power running through it, but my saw is on a 32A plug, and they don't make smart switches for those
There are off the shelf solutions for monitoring either via wiring your machine through the device, or through a CT clamp - Sonoff POW or Shelly EM for example.
I was worried about the ones that 'intercept' power to the machine, on startup the current spikes to about 100A, I don't think these things were designed for induction motors.
The ones with a CT clamp still need to be wired into your mains box, I'm guessing in order to constantly read the grid voltage to accurately calculate the power consumed - they're used for monitoring power consumption, so that makes sense.
I don't really need an accurate reading, I just need to know if the thing is on, so I thought about vibration sensors, movement sensors that would look at the blade from underneath, all sorts of things, as I couldn't find an off the shelf solution with a CT clamp that doesn't need to be wired into the mains box, My saw isn't near the box and I wouldn't trust myself wiring it in, so I'd need a sparky as well and costs add up.
Then I came across this video:
It explains how to create your own current sensor that integrates into Home Assistant.
It sends the consumed power to home assistant, where I've set up an automation to turn on the dust extractor (which is on a smart plug), as soon as there is power on that CT clamp.
I've not calibrated it very well so I've set mine to turn on if the power is above 300 watts, I didn't bother dialing it in, as I don't need to know the consumption, just that it's on.
You need three things:
- A ct clamp
- A teeny tiny smart home computer board
- A board that converts the signal from the CT clamp to something that the tiny board understands
- This is a newer version of what is used in that video, both should work
You need some basic soldering skills to solder some pins, but other than that, it's just some configuration in Home Assistant.
The video I linked earlier really helped, along with this one, as I've had no experience with ESP Home. I pretty much just copied the config from the first video, except I've reduced the reporting interval to half a second, instead of the default 5. I then excluded saving history for that device in Home Assistant so that it doesn't eat up storage.
The only problem I've got is that it takes around 30 minutes for the board to connect to WiFi, it should only be a few seconds.
From what I've read, the board itself could be defective, so I got in touch with the seller, but once it connects, it's solid, so not the end of the world for now.
The entire thing is tiny enough to not get in the way, I just need to build a case for it.
The earlier mentioned smart plug for the extractor is pictured below, along with a tactically placed clamp on the 'on' switch.
