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From: hans@umd5.umd.edu (Hans Breitenlohner)
Newsgroups: sci.electronics
Subject: Re: TTL Questions
Message-ID: <1795@umd5.umd.edu>
Date: Fri, 17-Jul-87 14:22:04 EDT
Article-I.D.: umd5.1795
Posted: Fri Jul 17 14:22:04 1987
Date-Received: Sat, 18-Jul-87 16:57:47 EDT
References: <1395@crash.CTS.COM>
Reply-To: hans@umd5.umd.edu (Hans Breitenlohner)
Organization: University of Maryland, College Park
Lines: 12

In article <1395@crash.CTS.COM> rpluth@pnet01.CTS.COM (Ron Pluth) writes:
>
>    1.  What's the easiest way to go about interfacing a TTL
>output (from, say, a standard S or LS AND gate) to a relay, for
>controlling anything from automobile (12VDC) to house (120VAC)
> ...

One effective way to convert from logic levels (including LS and CMOS)
to power levels appropriate for driving relays is to use VMOS transistors.
Like CMOS logic they do not require any extraneous drive current in either
the 'on' or the 'off' state.  Radio Shack used to carry some, I have not
checked recently.