How do I make this switch work?

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j

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Nov 9, 2003, 1:11:01 PM11/9/03
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Sorry for the cross posting, wasn't sure where to put this. I am a
woodworker and I have a table saw and a dust collector the saw is
220volts and the collector is 110volts. When I turn the saw on I want
the dust colector to automaticaly come on. Sears sells a switch that is
the right idea but it only works for 2 tools on the same 110volt circuit

http://www.sears.com/sr/javasr/product.do?BV_SessionID=@@@@1411227950.1068401263@@@@&BV_EngineID=ccdladcjlgihhfhcehgcemgdffmdflg.0&vertical=TOOL&pid=00924031000&bidsite=CRAFT

I don't think that it can be very difficult. can someone point me in the
right direction to start figuring outhow to make one that is more flexable?

tia
jw

jw_nyc at yahoo dot com

Michael

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Nov 9, 2003, 5:53:33 PM11/9/03
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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.

j <j...@nospam.yea> wrote in message news:<Vqvrb.19754$9M3....@newsread2.news.atl.earthlink.net>...

j

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Nov 9, 2003, 6:37:05 PM11/9/03
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Michael wrote:
> Why cant you use dust collectors and tools of the same voltage?

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.


>
> 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.


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
10 amps or so

jw

N. Thornton

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Nov 9, 2003, 7:31:49 PM11/9/03
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j <j...@nospam.yea> wrote in message news:<Vqvrb.19754$9M3....@newsread2.news.atl.earthlink.net>...

> Sorry for the cross posting, wasn't sure where to put this. I am a

> woodworker and I have a table saw and a dust collector the saw is
> 220volts and the collector is 110volts. When I turn the saw on I want
> the dust colector to automaticaly come on.

> I don't think that it can be very difficult. can someone point me in the

> right direction to start figuring outhow to make one that is more flexable?

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

Jim Thompson

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Nov 9, 2003, 7:37:02 PM11/9/03
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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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| Phoenix, Arizona Voice:(480)460-2350 | |
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I love to cook with wine. Sometimes I even put it in the food.

Rheilly Phoull

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Nov 9, 2003, 11:19:55 PM11/9/03
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"Jim Thompson" <inv...@invalid.invalid> wrote in message
news:a9ntqvsg77vtudh6b...@4ax.com...

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

--
Regards ............... Rheilly Phoull


j

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Nov 10, 2003, 7:50:16 AM11/10/03
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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
110 and max amps of 15. That is in effect what I want to do and if I can
buy that for $5 - $7 I can wire it up myself.

thanks

Bushy

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Nov 10, 2003, 8:10:33 AM11/10/03
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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


Watson A.Name - Watt Sun, Dark Remover

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Nov 10, 2003, 10:22:24 AM11/10/03
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In article <boo2dl$aq2$1...@bunyip.cc.uq.edu.au>, ple...@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!

> Hope this helps,
> Peter

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Jeff

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Nov 10, 2003, 3:35:32 PM11/10/03
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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.


"Jim Thompson" <inv...@invalid.invalid> wrote in message
news:a9ntqvsg77vtudh6b...@4ax.com...

GPG

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Nov 10, 2003, 8:20:15 PM11/10/03
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220 V AC relay on tool motor wires. Contacts to switch dust collector.
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