Re: [APML] Auto Guiders.

["William R. Mattil" <wrmattil@ix.netcom.com>]

Alan Voetsch wrote:

>Hey Bill,
>
>--- "William R. Mattil" <wrmattil@ix.netcom.com> wrote:
>  
>
>>Take the relay closure provided by the alarm relay and some +12 volts
>>    
>>
>
>  
>
>>(I'm you have some of that around right ? :^) ) And wire up a louder
>>alarm.
>>Mine provides a closure that I bring into the house so if I happen to
>>be  in there I can hear the alarm.
>>    
>>
>
>I've heard of this being done before. But I'm the kind of guy who, if I
>started messing around un-necessarily inside the box, would blow
>something up. Think I'll leave well enough alone.
>  
>

Because it is only a relay closure there is nothing you can do to damage 
it unless you tried to switch extremely high voltage or current with it. 
Even then you would only weld the contacts or pit them. Wouldn't 
actually damage the ST-4 itself.

>Incidentally, is there any way to tell if one of the relays stops
>working other than excessive trails on the shots?
>

This would be the worst method of making that decision. Its much more 
likely that there was some flexure causing problems than a relay.

> Will there be
>calibration failures? Something else to look for?
>  
>

Bingo ! this would be the first place it would show up I would think. 
You could actually test the relays by removing them and then testing 
them by applying the proper voltage and checking for closures and opens. 
but you would have to use short pulses I would think.  I have a plethora 
of spare relays for the ST-4 and have yet to actually need to use one. 
The relays seem to be pretty robust in my experience.


Regards

Bill

-- 

William R. Mattil  :  http://www.celestial-images.com


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