How do I make this switch work?

Why cant you use dust collectors and tools of the same voltage?

If the sears device you are describing is a device which detects when a tool is drawing current, and then switches on a vacuume, then there is no reason why you cant run as many tools as you like from it providing you dont overload it by using too many tools at once.

I suppose I could get a new dust collector that would run on 220 volts but then because of the amount of amps these tools draw I wouldn't want to run them on the same circuit anyway.

yes, but you've hit the nail on the head. The tools I want to use draw too much current to run on one circuit. In addition there is a limit to the number of amps you can run through the Sears defice, I think it is

jw

A current relay in the supply to the power tool can switch your 110v when tool is powered. A small number of turns of thick wire on a standard relay would do it, long as its contacts are suitably rated.

Regards, NT

Pondering my navel here... I wonder if you couldn't drive a low-voltage relay via a current transformer? That would save you having to try to put a winding on a relay bobbin that you probably can't get your fingers into.

...Jim Thompson

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flexable?

How about a 110vac relay powered by one of the switched outlets ??

OK so there is something called a current relay that I might be able to use. Is this something I should be able to find at an el;ectronicds supply house? Maybe someplace on the internet? Any recomendations?

How are current relays rated and how do they work. The relay is an on/off switch activated by the rise and fall of current. Are they rated for switched and switching volts and current? Can I say I want a current relay that that will sence the current in a 220 volt appliance, the max current on the appliance will be 15 amps and I want the switch activated at threshold of 2 amps. The appliacne being switched will have voltage

thanks

jw

jw_nyc at yahoo dot com

Have not tried with AC but would probably work. Someone else may have more experience and may post extra info.

There is a device called a reed relay that is a simple set of contacts in a glass bulb that is often used inside a specialised coil. The reed relay itself is only a couple of dollars for both parts and they are often available separately.

The reed contact can be used in a coil of your own design, and a dozen turns of one of the wires to your machine with about 15 amps should cause the reed contacts to close. (Note I have only used this with DC but AC may work just as well) The reed contacts can then be used to operate a larger relay that can handle the current required for your dust collector.

As you can see I don't know for sure if this will operate with the Ac but suspect it will. Be careful with your wiring. For the couple of bucks it will cost to get a reed relay and the time to insert in a couple of turns of the active supply line it might be a worthwhile experiment.

Hope this helps, Peter

In article , snipped-for-privacy@reply.to.group mentioned...

Problem is that the reed relay contacts are so light that they will probably open and close 120 times a second, once for each half cycle of the AC line. I don't know if they are rated for millions of cycles, but this would be a good way to find out!

I saw a shop set up like this a long time ago - the main feed for the machine breaker box panel had a little current transformer on it. A hall effect sensor would also work.

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flexable?