Wall warts - test-drb@ccmp.vtda.org

21 Jan 2009

Message: 26
Date: Tue, 20 Jan 2009 22:01:00 +0000 (GMT)
From: ard at p850ug1.demon.co.uk (Tony Duell)
Subject: Re: Wall warts; was: hams on classiccmp
To: cctalk at classiccmp.org
Message-ID: <m1LPOef-000J3QC at p850ug1>
Content-Type: text/plain

Tony Duell wrote:

...
  I feel these standard, or at least the 'CE
mark' is part of the  
 problem,
 and here's why....

 It would apperar there are either loopholes in the standard, or  
 plenty of
 cheap electrical devices (including wall-warts) that have invalid CE
 marks on them, in that I've seem enough devices that I don't consider
 safe. The problem is that if the wall-wart carries the CE mark, then  
 as
 you said, the certification for the whole product becomes a lot  
 easier,
 and if there are any problems later, a large part of the defence is  
 'But
 the wall wart met the appropriate CE standards'. 
Specifically, what do you consider unsafe about current wall-warts?  
I've found all the devices I've been in of late to be well designed  
and quite safe - cheap, yes. Perhaps you have been expecting  
accessible fuses. For some time the fuses have been located next to  
the core under the windings and act both as current and thermal  
protection devices. Most of the ones I've opened up have both the  
primary and secondary fused. I have yet to find one with the turns  
actually fused open. Granted, it's a bit more work to repair one, but  
well worth the time it takes to unwind the primary and secondary,  
replace the fuses, and rewind same. ;=)

...
  But when manufacturers were entirely responsible for
what their  
 devices
 did, they made darn sure they were safe. Said manufacturers did not  
 want
 to end up paying out large amounts of damages. SO th products really
 _were_ safe. 
And in so many cases the manufacturer's concept of what was safe was  
not that of the court. Consequently, the certification standards.

...
  I offer as an example the PSU brick for the Philips
G7000 video game.
 It's a bit like awall-wart, except it has a mains input cable that you
 wire to a suitale plug. But inside that brick (which is nicely screwed
 together), there are no fewer than 3 protective devices. A mains-side
 fuse, a secondary fuse, and a thermal fuse (on the mains side). 
And the reason the warts are now sealed is that some bright person,  
having no idea of what he/she/it was doing, opened one and (chose one)  
1. set it ablaze, 2. caused some sort of laceration on a sharp edge,  
or 3. left it open and plugged in and fried fido. We now have a  
mentality that disallows Darwinism and hence the large number of  
people developing standards to guide and protect the designer/ 
manufacturer. Again, what you might consider safe might not be what  
others consider safe.

	CRC