dust extraction remote turn on

[wizer]

Sorry Mark, but it is bloody clever!

 

[kityuser]

Yes thanks Tom, it does work well, and was very cheap to put together, about £25 IRC plus the blastgates.

I've been meaning to post about this for ages so I'll take the opportunity now.

I can't take much of the credit for it. The idea was mercilessly nicked from the system Axminster used to sell a few years ago (which like the current one was hideously expensive for what it was), and all the clever stuff was done down the road at a local electrical supplier.
It's basically a box with a 13A socket a flylead witha plug on, kind of an overgrown extension cable.


Inside there are only 2 things: a big relay which turns the power to the socket on and off, and a transformer which provides the 12v for the switching side of things.


Stick 'em in the box,

Run some bell wire to microswitches on the blastgates (wire them in parallel obviously)


Attach switches to blastgates using any arrangement you like that works for you. I drilled holes like this to allow the necessary movement of the actuator.


With hindsight I should have chosen anothr arragement, as this one turns the extractor off when the gate is almost fully shut, forcing it to run against a sealed system for a second or so. It also has the disadvantage that should there be any obstruction that prevents the gate closing completely then the switch doesn't actuate.

very clever and very impressed.

can I have the RS part numbers for the transformer and relay PlEaSe... :wink:
by my eyes it looks like
349-327
805-675

Steve

 

[wizer]

Mark is the roller arrangement on top of the micro switch your addition or did they come like this? I have a bag full without that bit.

 

[Racers]

Hi,

They come like that but you can bend a inverted U shape in the arm if it is a long one.


Pete

 

[WellsWood]

Mark is the roller arrangement on top of the micro switch your addition or did they come like this? I have a bag full without that bit.

I had a couple without rollers from the same local place as the relay etc. but I found them tricky to mount. The ones with rollers came from Maplins for about £1.50 each. They're clever because you can wire them either way - normally off or normally on - which gives a lot of scope for mounting.

Steve, tranny is RS 805-675, and relay is 349-327.

 

[wizer]

cheers, Mine where out of a arcade machine so you wouldn't need that bit.

 

[Shultzy]

Check out the LetsAutomate site, it has all sorts of remote control units many that run through the mains circuits.

http://www.letsautomate.com/index.cfm?

 

[mpooley]

Well I have the pull cord system in the middle of the shop - its never far to walk and you cant lose it!

I dont like the idea of a sensor for the motors switching on as some jobs eg a small cut on a chop saw will have the extractor winding up and down over and over again and if you are only chopping one bit then you will have cut it before the extractor gets going!

its a much better idea to put switches on the blast gates but you mentioned worrying about the extractor still running with the gate shut.
well dont worry as the motor works LESS with no air running through it :shock:

Mike

 

[SeanG]

How do the automatic switches work with extractors with start/stop switch boxes?

If I controlled the power to the plug with the auto switch the unit still wouldn't come on unless I pressed the start button.

Probably a simple and stupid question to you lads who understand electrical stuff, but a complete mystery to me!!

 

[ivan]

Any extractor bigger than a domestic vacuum (and even they are hard on 20A rated switches) needs a proper starter with a contactor; running currents may be modest. but motors can start up with a big surge (too short to blow fuse, but hard on switches)

I uses to have a 45A (shower) pull switch rigged up with a thin wire (multistrand galv'd) across the workshop just under ceiling level. Wire, because although an extractor fire is not very liklely, I did not want to find an unexpected air assisted blast of flame burning through a bit of string....Doubting Thomas can check the HSE website for lively pictures of succesful spark ignition of dust stream and ensuing bag fire.

I have come to prefer the radio controlled effort I got from Lidl - a small remote and 4 3 pin sockets, for a tenner. The extractor starter's contactor is energised by a cable plugged into one of the remote controlled sockets (see wiring diagram inside starter box)

Such remote controlled sockets are not suitable for directly switching heavy inductive loads (ie motors). If this sounds more than you want to do yourself, wiring up an existing starter to a radio socket shoudn't take a sparks more than 15 mins.