Subject: Re: Timer question

From: [email-masked]
Date: Wed, 04 Dec 1996 08:11:56 -0500

Randy R. Cox wrote:
> 
> I need a timer to control my 2 1/2 gallon rock tumbler which I use for
> silica slurry for ceramic shell mold building.  Uses 1/3 horse motor, 7
> amps @ 115 volt.  Motor rated contacts would be a plus, but I have a
> small starter which I could use with a relay from timer.  Need 4 to 6
> cycles per hour with adjustment for on time. I currently run the motor
> 24 hours and this is no doubt a waste of power. I would like something
> cheap of course!  Any Ideas?
> 
> Thanks,
> Randy Cox

You might consider a timer assembly used for swimming pool pumps, or
lawn sprinkler pumps they have contacts that are rated for motors. On /
off cycles are set with adjustable trip levers. There several
manufactures of this type of timer the one that comes to mind first is
Intermatic brand sold in most hardware and home centers. This type is in
the $50 price range. To do the same thing a lamp timer powering a
suitable relay could be done for about $8 also avaliable from Intermatic
and others.

pht

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From: [email-masked] (Reg H. Beardsley)
Date: 4 Dec 1996 18:03:55 GMT

In article <[email-masked]>, Richard McBride <[email-masked]> writes:
|> Randy R. Cox wrote:
|> > 
|> > I need a timer to control my 2 1/2 gallon rock tumbler which I use for
|> > silica slurry for ceramic shell mold building.  Uses 1/3 horse motor, 7
|> > amps @ 115 volt.  Motor rated contacts would be a plus, but I have a
|> > small starter which I could use with a relay from timer.  Need 4 to 6
|> > cycles per hour with adjustment for on time. I currently run the motor
|> > 24 hours and this is no doubt a waste of power. I would like something
|> > cheap of course!  Any Ideas?
|> > 
|> > Thanks,
|> > Randy Cox
|> 
|> Randy,
|> The stepper switch found in any washing machine comes to mind here, but
|> there must be  cheap pc hardware/software combo out there somewhere that
|> would go with what you have????
|> 
|> Rich

A 555 timer and a relay.  A dual 555 if you want the on time and off times
to be asymmetric.  It's the basic circuit in the application notes.
Radio Shack used to sell a whole book of 555 circuits by Forrest Mims.

-- 

------------------------------------------------------------------------
               I am solely responsible for the contents...

Reginald H. Beardsley                                      [email-masked]

              Exploration Software Consultants Incorporated
------------------------------------------------------------------------

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From: [email-masked] (Alan Shinn)
Date: Thu, 05 Dec 1996 00:25:35 -0800

> cheap of course!  Any Ideas?

A cmos version of a 555 timer would make a good "heart" for your system,
it *would* need a relay -preferably solid state-- I bet all could be
gotten at Radio Shack.

-- 
Al Shinn   (Tinker)
alshinn@ sirius.com

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From: [email-masked] (Knut Pedersen)
Date: Thu, 5 Dec 1996 11:00:29 GMT

In article <[email-masked]> [email-masked] (Alan Shinn) writes:
>From: [email-masked] (Alan Shinn)
>Subject: Re: Timer question
>Date: Thu, 05 Dec 1996 00:25:35 -0800
The 555 is sensitive to sparks on the 115 V power line, if the duty cyclus 
is finished, and you start an other motor the 555 will usualy start a new 
cycle. 
Knut

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From: "Randy R. Cox" <[email-masked]>
Date: Tue, 03 Dec 1996 18:08:59 -0600

Thanks,
Randy Cox