Re: [CAD_CAM_EDM_DRO] Re: coolant pump control questions

Hi guys;

Most folks don't even think of it, but a 555 chip makes a dandy small relay
driver. You can configure it to take either a high or low input signal, and
render either a high or low control signal. Anti-ringing diodes/caps needed, of
course.

Bill

On Wed Jan 29 05:57:05 2003 James Cullins wrote:

>Most solid state relays will work from 3 to at least 12 many higher. If you
>cooling system
>is 110vac then the reed relay would not drive it anyway. If you check
>www.jameco.com
>search for 139053 part#. It is a 240D25 relay up to 240vac and 25 amps
>operates from 3 to 32 volts. It doesn't list the drive current but I would
>recommend that you use a transistor to drive it with. Put a 1k resistor in
>series with the driving pin and the base of the transistor. wire the emitter
>to ground and the collector to the - pin on the relay and the + pin to 5v.
>This is assuming you have 5v available.
>Hope this helps.
>Jim
>----- Original Message -----
>From: <mabw@...>
>To: <CAD_CAM_EDM_DRO@yahoogroups.com>
>Sent: Tuesday, January 28, 2003 11:12 PM
>Subject: [CAD_CAM_EDM_DRO] Re: coolant pump control questions
>
>
>>
>>
>> Yes , the problem I have is the control side of things, I don't know
>> the range of the PC . By "switching" on the coolant in the software I
>> get a 5 volt reading on pin 1 of the parallel port but it will not
>> switch the relay which is a 5 volt 10 ma. When I connect the relay to
>> pin 1 and the other side to earth the volts drop off to almost zero I
>> am guessing here at saying there is not enough current? this is the
>> smallest rated relay I could find (it is a reed relay) I could not
>> find a solid state relay in 5 volts.
>> help please!!!!!!!!
>> thanks
>> Mark
>> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude
>> <davemucha@j...>" <davemucha@j...> wrote:
>> > Hi MArk,
>> >
>> > Not sure if I understand yoru question fully.
>> >
>> > relay must be sized to or above the motor volts and amps. should
>> be
>> > just that simple. 1hp motor, you need to get a relay that can
>> handle
>> > a 1hp load, not just any 10 map relay.
>> >
>> > Relays are usually rated for Amps DC, Amps AC, and Inductive loads
>> or
>> > in hp.
>> >
>> > If you are asking about the control wiring of the relay, just look
>> > for a solid state relay in the 5 volt range of the PC, if you are
>> > driving from a PC.
>> >
>> > if you cannot find a realy with a good fit, you may considder using
>> a
>> > mini 1/4 amp relay and allow that to drive the coil of a larger
>> relay.
>> >
>> > Dave
>> >
>> >
>> >
>> >
>> >
>> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "markpowerplus <mabw@b...>"
>> > <mabw@b...> wrote:
>> > > Hi Guys!,
>> > > How do I set up the coolant pump on my 4 axis cnc mill? I am
>> using
>> > > cncpro. Do I use pin 1 and an earth to a relay switching power to
>> > the
>> > > pump? If so what would be a suitable relay specification wise re
>> > > volts and current for the relay? If not ,how? I know how to do
>> the
>> > > software side of things just not the physical side of it.
>> > > thanks
>> > > Mark

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