Re: [APML] 2 More ST-4 questions

[Philip Perkins <philip@astrocruise.com>]

Andreas and others,

Correct - the ST-4 draws approximately 1 amp.  The mention of 2 amps must 
have been a mistaken reference from the STV spec.  One of the significant 
advantages of the ST-4 for remote stand-alone autoguiding is the relatively 
low current drain.

Also the ST-4 does not have a shutdown procedure - it does not have a high 
performance cooler such as is fitted to the high end ST-xx cameras.  These 
cameras are capable of cooling to as low as 48 C below ambient (with 
additional water cooling).  The ST-4 has a low performance unregulated 
cooler that does not experience significant thermal shock when power is 
disconnected - never enough to damage it.  This situation is no different 
from the low performance peltier coolers fitted to many other devices, 
including electronic cool boxes - these do not need a shutdown procedure 
either.

If Meade have a shutdown procedure for their (apparently equivalent) 
cameras / autoguider then the first thing to check would be whether the 
type of cooler, the electronic control circuitry, and the current drain are 
all the same.  If they are not the same, then no comparison can be made.  I 
wouldn't particularly trust the advice of Meade in this regard unless I was 
sure I was talking to an expert in this field.  In the case of SBIG, the 
whole company are experts in this field.

Regards
--Philip

At 02:17 27/04/03 +0200, you wrote:
>Hi Alan and Jim,
>
>well, as far as I remember it's more about 1 amp but I have to check it
>again. The STV needs about 2 amps as far as I know.
>
>Best regards
>Andreas


Philip Perkins - philip@astrocruise.com
Wiltshire UK & Luberon France
Astrocruise - http://www.astrocruise.com

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