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Re: Electronics help - Sp3500 project

To: "Michael D. Nugent, Ph.D." <nugentmd@gte.net>
Subject: Re: Electronics help - Sp3500 project
From: "Paul Cartwright" <pcart@willinet.net>
Date: Thu, 26 Oct 2000 23:19:55 -0700
I have made an error in terminology in my previous post.  I believe that
"normal" state is without the coil being energized.  Therefore the relays
that are needed  are a 12v normally open (NO) and a 12v normally closed time
delay (NCTD).
Time delay relays come in two flavors, "on" delay and "off" delay.  Off the
top of my head, I do not remember the correct terminology, however you want
the kind that has a delay before opening the contacts.

One further thought.
If the ignition switch can handle the 20 amps, the 12v NO relay can be
iliminated.  Energize the coil of the 12v NCTD from the ignition and connect
the ignition to one side of the NC contacts.  Connect the load to the other
contact and you should be good to go.
Paul
>
> I believe I have a solution that would be easier to implement.  It
involves
> using a 12v normally closed (NC) relay and a 12v normally open, time delay
> relay (NOTD).  The coils on both relays are powered by the ignition.  To
> supply the power for the load connect the source to one of the contacts on
> the 12v NC relay and the other contact to one of the contacts on the 12v
> NOTD  relay.  Connect the load to the other contact on the 12v NOTD.
>
> When the ignition is turned on the power will be supplied because the 12v
NC
> relay close right away and the 12v NOTD will be closed until the time
delay
> is reached.  When the time delay is reached the 12v NOTD will open,
stopping
> current from flowing to the load.
>
> If needed I could draw the circuit and email it to you.
>
> Please note: I am not an electrical engineer, use at your own risk. 'Nuf
> Said.
>
> Paul Cartwright
>
> > >I need help figuring out what parts I need to do this:
> > >- initially pass current (12v, <20amps)
> > >- stop the flow of current after 5-10 seconds
> > >- preferably not flow again until power is turned off and back on
> > >(staying off for 5-10 seconds would be okay).
> > >
> > >I'm thinking of a slow, silent turn signal flasher (but preferably one
> > >that would only flash once without a reset).
> > >
> > >Easy to do, hard to do?  What parts do I need and how must they be
> > >arranged?
>
>
>


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