Olin Lathrop wrote:

>William Bross wrote:
>  
>
>>And yes, the test unit passed all the
>>hipot tests in the lab, it's just line testing every unit I've
>>challenged.
>>    
>>
>
>So apparently this unit provides either isolation or insulation from the
>input power to something else.  That sounds like a important spec that could
>have bad consequences when others rely on it but it fails.  It seems to me
>that a quick hi-pot test on every unit in production makes sense.  Two
>minutes might be excessive, but you need some way to verify each unit is
>being produced with the isolation promised.  How do you otherwise propose to
>find accidental dirt or solder or whatever accross the isolation barrier?
>
>
>********************************************************************
>Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
>(978) 742-9014.  Gold level PIC consultants since 2000.
>  
>
Good question Olin.  All completed units get at least a 72 hr. extended 
temp. burn-in.  Then the bad product gets weeded out in the final test / 
calibration / certification phase.  The automated tester will kick out a 
unit even if it calibrates but the zero and span offsets end up outside 
our calculated normal range.  Then all failures get a thorough visual 
inspection and then corrective action.  That takes care of any isolated 
input side problems.  The DC power input gets impedence checked and then 
input current is measured.

Also, each isolated section has A/D channels monitoring VDD and 
regulator output current.  Wouldn't any breach of any of the isolation 
barriers throw the measured current for each section off?  But I can see 
the argument to still do the testing too.  We'll wait for the ruling by 
the authorities.

Bill
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