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What ordinary relay would you suggest?
I work on site most of time and requires 110v tools
Any suitably rated contactor with an off timer module which has a coil compatible with the control voltage you select.
So is the control for your workshop that you use to support your site work?
As in as part of your business endeavour?
 
Was chatting to my neighbour he suggested that a resistor might fool the extractor to think there’s a tool being used?

Anything that draws more current than the threshold required to activate the current sensor should trigger the extraction no matter what it is.
Not sure why you would want to connect a resistor though - it will need to be quite hefty to take the power and you might be better to consider a tubular heater.
 
Anything that draws more current than the threshold required to activate the current sensor should trigger the extraction no matter what it is.
Not sure why you would want to connect a resistor though - it will need to be quite hefty to take the power and you might be better to consider a tubular heater.
I was looking for a neater solution that perhaps I could install inside the case of the extractor but as you say the resistor required would be too big after doing a few calculations
Think I might go for the set up that has the remote switch and current sensor the install inside a tstak case
 
We began with a heater pullswitch (20A?) and a pull cord run along the ceiling. Tug on, tug off, where ever you were. But not quite, so progressed to an Aldi/Lidl remote switching set up (~£10 for 4 sockets), with the remote in my pocket. The motor starter was wired up as a contactor, powered by a 3 pin plug inserted in the remote socket adapter, in turn plugged in to a 13A socket. Hand in pocket, push buton on/off, lierally wherever you are. Hay Presto!
 
I was looking for a neater solution that perhaps I could install inside the case of the extractor but as you say the resistor required would be too big after doing a few calculations
Think I might go for the set up that has the remote switch and current sensor the install inside a tstak case
Hey HDC83 - did you ever get your auto extraction working?
Reason for asking is I need to make one now.
However, I’ve decided to take a different route and plan to use an Arduino Nano clone with a current sensor. This should allow me to preset start and stop delays as well as fit a manual override switch.
I’ll keep you posted if you are interested in how it works out.
 
Hi hamsterjam
Yes I got it sorted here’s some pics
596283C1-497C-4616-8370-2D0C236DB1DC.jpeg
3DABD99D-C3C2-4478-ADA6-B95270CCC2EA.jpeg

It works great but since I sorted it, I have gone for a LPHV extractor and changed to bin type HPLV extractor using a combination of the both. The tstak is now just for the job site.
I going the full automated route using Arduino mega, remotes, sensors and actuators to open blast gates, here’s me testing it.
1D207355-6AE7-41F2-95A5-54645F252A17.jpeg

I’ve been playing with writing code. Just haven’t got round getting it up a going yet, just too dam busy with work.
 
Hi hamsterjam
Yes I got it sorted here’s some pics
View attachment 112946View attachment 112947
It works great but since I sorted it, I have gone for a LPHV extractor and changed to bin type HPLV extractor using a combination of the both. The tstak is now just for the job site.
I going the full automated route using Arduino mega, remotes, sensors and actuators to open blast gates, here’s me testing it.
View attachment 112948
I’ve been playing with writing code. Just haven’t got round getting it up a going yet, just too dam busy with work.

Oh wow! Nice one.
I’m planning to squeeze a Nano with a 5v psu plus a current sensing and a relay board into a double socket blank.
The Ardiuno parts have arrived I just need the time to build it and write the code :)
What PSU have you used? - It looks quite chunky. I might bust open a plug top unit and use the circuit board from it.
 
Used this one 12V 5A DC Universal Regulated Switching Power Supply Converter, 60W Adapter Transformers for LED Strip Light,Radio, Computer Project,Video Surveillance,Probe Signal Lamp: Amazon.co.uk: DIY & Tools
Yes the power supply is a bit overkill at 12v 5amp. The nano needs less than 1 amp so the psu only needs to be small, just make sure you have some air flow or heat sinks as the electronics can generate some heat. Since the first pics I have added a 12v computer fan to keep things cool.
 
An electronic engineer here.

You only need a 1A or less 12V PSU - a small wall-wart would do the job. The diodes you are using for the "logical OR" could be pretty much any small diode, but a 1N4001 would be just right and very cheap.

You have NO protection on this circuit. The PSU input should be fused at 1A or preferably less - maybe 500mA but use a T type (slow blow) fuse as the PSU inrush could blow a fast fuse.
The feed into the output SSR also needs appropriate overload protection. SSRs are good and avoid many of the problems inherent in electromechanical switching. Depending on the load, the SSR may require a heatsink.

I presume you are intending to use yellow commando sockets for all this. I would also use Wago 221 series (or similar) connectors for the 110V stuff (even for the 12V stuff too).

It's late and I haven't looked at your schematic closely, but will tomorrow.

Edit: I use a fair bit of Sonoff stuff which is really neat kit. E.g. my workshop lights are controlled by some of these:

https://smile.amazon.co.uk/dp/B07KYPC1RKhttps://www.amazon.co.uk/dp/B07S8BZKRQ
 
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In my opinion you are getting to complicated for a simple task, remember the basic rule in engineering "KISS". For your needs you need detection, ie something request extraction and then an output to turn the extractor on along with any gates. As for logic, think back to the days of relay logic and again for your task it is easy. Two sets relay contacts in series will give you the "AND" function and Two sets relay contacts in parallel will give the "OR" function.
 
Spectric and Nickds1,
I started looking at COTS (common off the shelf) parts but the Arduino route although overkill is working out far cheaper than the alternatives and is more flexible insofar as I can add a half second start delay to reduce the startup spike and a stop delay to keep the extraction on for a few seconds after the tool/machine stops.
In addition Arduino is arguably COTS in this day and age.
I need to add a power supply but so far it’s cost me less than tenner….,
Arduino clone is £3.90 plus £2.45 for the optoisolated relay + £3.15 for the current sensing units including delivery. I am expecting the relay to need replacing as although it is rated 10A at 240v, I have my doubts it will be happy switching the 1kW inductive load of the extractor.
 
An electronic engineer here.

You only need a 1A or less 12V PSU - a small wall-wart would do the job. The diodes you are using for the "logical OR" could be pretty much any small diode, but a 1N4001 would be just right and very cheap.

You have NO protection on this circuit. The PSU input should be fused at 1A or preferably less - maybe 500mA but use a T type (slow blow) fuse as the PSU inrush could blow a fast fuse.
The feed into the output SSR also needs appropriate overload protection. SSRs are good and avoid many of the problems inherent in electromechanical switching. Depending on the load, the SSR may require a heatsink.

I presume you are intending to use yellow commando sockets for all this. I would also use Wago 221 series (or similar) connectors for the 110V stuff (even for the 12V stuff too).

It's late and I haven't looked at your schematic closely, but will tomorrow.

Edit: I use a fair bit of Sonoff stuff which is really neat kit. E.g. my workshop lights are controlled by some of these:

Hi Nick

I had the PSU left over from another project so used what I had, I also done away with the diodes they weren’t required.
Never even thought about fuses but I will add some. One of these for the PSU
https://www.amazon.co.uk/Multicomp-PPFH-4432-Panel-Holder-250Vac/dp/B0839VJSX2Something like this but with a higher rating for the SSR

since the pics the SSR has been fitted with heat sink and have used wago fittings throughout

Thanks for your input
 

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