17 Jul 2003, 18:13, Jasen Betts (3:640/1042), wrote to JAY EMRIE:

Hi Jasen.

 JE>> Tore (literally - the screws that held it together were imbedded 
 JE>> 1 1/4" deep and had a head that matched  nothing I had) the old 
 JE>> one apart. The idiots had hard wired the input of the voltage 
 JE>> dropping transformer directly tp the 110 V AC input. The on/off 
 JE>> switch only switched the 12V output! No wonder it hummed when 
 JE>> turned off or on!

 JB> 12V switches must have been cheaper....

Cost probably wasn't a factor.  Over here low voltage stuff, like the
output from a wall-wart, isn't subject to UL fire underwriters testing and
approval.  The wall-wart itself must pass inspection, but nothing attached
to it falls under those rules.

In Jay's case, the transformer was built-into the lamp, so the whole thing
had to be 'approved' anyway.  Doesn't make much sense.

I'll throw out a few possibilities:  

A line voltage switch would need to handle switching the inductive load of
the transformer, would need better flashover protection at shutoff, and be
made with high voltage insulating plastic.

A low voltage switch would need heavier contacts to handle the higher
current, but could be made with any old plastic, and could be smaller due
to less airspace needed for flashover protection.

Then again, it could have been a rather simple design integration from an
earlier model that did use an external wall-wart.

????????

     Good luck...  M.

--- Msged/386 TE 06 (pre)