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From: "Michael A. Terrell"
Subject: Re: I can't find the solution for such "simple" problem. Motorized
Date: Sun, 05 Jan 2003 00:56:44 -0500
Organization: Have you seen my bench? No, really! Where is it?
X-Mailer: Mozilla 4.61 [en]C-CCK-MCD (Win95; U)
> I have motorized the drapes on my living room and was going to install
> one microswitch at each end of the travel.
> The switch would operate a dpdt relay that invert the motor sense and
> at the same time would switch power off.
> A push ON switch would reestablish the power and the cycle would be
> repeated at the other end. Simple isn't ?
> I can't design a circuit that can do the desired action without using
> at list one more relay , a special type of relay ( ratchet ) or other
> mechanical operating system.
> Can you ?
Find one of the old C-band satellite antenna controllers. they drove
24 volt DC motors, and used a pair of limit switches to limit travel by
paralleling a large diode across each switch so you had to reverse the
current flow before the motor would move. then you can either use the
East / West buttons, or program two positions (or more, if you want to
open them part way. Then just push the button for the desired position.
Michael A. Terrell
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