relays

Archiver

Hi all. I am building a security alarm for my car using the Basic Stamp II.
I'm wondering what type of relays (specs) I should use to interface the
stamp with my auto accessories (parking lights, horn, dome light, starter
disable). Any info would be appreciated.

Tyson
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Archiver

I needed a headlight relay for one of our vehicles in a hurry. The Radio
Shack 275-226 relay worked fine. The contacts, (SPST), are rated 30 amps,
and the coil is 12 volts @ ~180 ma. Since the contacts are normally open,
you would have to activate it for normal vehicle operation. You could
easily drive it with a mosfet or power transistor operated from the stamp.

Ray McArthur

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Original Message

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From: Tyson Whitt <tysonwhitt@h...>
To: <basicstamps@egroups.com>
Sent: Monday, April 10, 2000 8:45 PM
Subject: [noparse][[/noparse]basicstamps] relays


> Hi all. I am building a security alarm for my car using the Basic Stamp
II.
> I'm wondering what type of relays (specs) I should use to interface the
> stamp with my auto accessories (parking lights, horn, dome light, starter
> disable). Any info would be appreciated.
>
> Tyson
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
>
>
>
>

Archiver

>From: "Tyson Whitt" <tysonwhitt@h...>
>Reply-To: basicstamps@egroups.com
>To: basicstamps@egroups.com
>Subject: [noparse][[/noparse]basicstamps] (unknown)
>Date: Mon, 17 Apr 2000 16:23:55 PDT
>
>Hi all. I am building a security alarm for my car using the Basic Stamp
>II.
>I'm wondering what type of relays (specs) I should use to interface the
>stamp with my auto accessories (parking lights, horn, dome light, starter
>disable). Any info would be appreciated.
>
>Tyson
>
>______________________________________________________
>Get Your Private, Free Email at http://www.hotmail.com
>
>
>
>

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

Archiver

Stampers,

How is a solid state relay different from an optoisolator and/or
mosfet? Will it hurt a solid state relay to turn it off and on with PWM
like it would a mechanical relay?

David Fixemer
fixemerd@a...

Archiver

This had come up a few weeks ago....
From my perspective, SSR's are the more expensive (lazy) way to go if you
want to integrate your design at a higher level. To explain, it's easy to go
to a catalog and select an SSR for controlling an AC load by searching specs
for your input logic level and your output requirement as zero-cross or
random firing and your speed needs. For DC loads, you may only need to find
one sized for your load. Using SSR's can thus save time in a design cycle.
Another benefit is that many are made to be easily replaceable in the field.

You can find a variety of input and output type combinations in
opto-isolators, and known quantities allow you to do more precise control if
you roll your own. You can select from a wide range of silicon devices to
switch your load. The component cost is typically considerably less, but
you'll need to integrate the parts onto a board, and will have to use DIPs
in sockets if you want field serviceability. A little more design work is
traded for significant cost savings in hardware in most cases.

Beware, however because many SSR designers have done good engineering in
support circuitry for both input and output protection which would keep the
beginner at the breadboard for a while longer than he might have expected.
Also, if you select an SSR, then have problems with it, plugging in another
won't solve anything. On the other hand, you can be sure of results when you
work at improving your own isolation circuit.

Either way, this goes along with one of my favorite thoughts: "If at all
possible optically isolate it"
Chris.

>

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Original Message

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> From: Production Technology, L.L.C. [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=7YCw8JO4ablIeIfdDWBZhk-49zwtOAhEGG62wFU-4K9CD76fuzgURobk-3GGLe2BvrEAwmEGGcNg-eMo]fixemerd@a...[/url
> Sent: Tuesday, October 30, 2001 11:47 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] RELAYS
>
>
> Stampers,
>
> How is a solid state relay different from an optoisolator and/or
> mosfet? Will it hurt a solid state relay to turn it off and
> on with PWM
> like it would a mechanical relay?
>
> David Fixemer
> fixemerd@a...
>
>
>
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