What can happen if a Wall Adapter Fails?

[royalmp2001]

For safety reasons, I need to know what are the REALISTIC chances of
120V appearing at the output of a failed basic 12V wall adapter.

I would have thought most likely the secondary or primary winding would
most likely go open-circuit, or the smoothing electrolytic cap or
bridge rectifier go open or short circuit....so I'm hoping that at
worst you get 0V at the output.

Can someone tell me the chances of a dangerous situation occuring.
What safeguard could I incorporate? Would a GFCI protector do the job?
Could I build a discreet GFCI into my circuit? Any ideas?

I intend to produce a commercial project powered with a wall adapter
that connects upto the human body.

Thanks

 

[Rich Grise]

On Wed, 16 Feb 2005 07:26:04 -0800, royalmp2001 wrote:

For safety reasons, I need to know what are the REALISTIC chances of
120V appearing at the output of a failed basic 12V wall adapter.

I would have thought most likely the secondary or primary winding would
most likely go open-circuit, or the smoothing electrolytic cap or
bridge rectifier go open or short circuit....so I'm hoping that at
worst you get 0V at the output.

Can someone tell me the chances of a dangerous situation occuring.
What safeguard could I incorporate? Would a GFCI protector do the job?
Could I build a discreet GFCI into my circuit? Any ideas?

I intend to produce a commercial project powered with a wall adapter
that connects upto the human body.

If I do your research for you, do I get paid commensurately?

Thanks,
Rich

 

[dB]

"royalmp2001" <royalmp2001@hotpop.com> wrote in message news:<1108567564.629415.104940@z14g2000cwz.googlegroups.com>...

For safety reasons, I need to know what are the REALISTIC chances of
120V appearing at the output of a failed basic 12V wall adapter.

I would have thought most likely the secondary or primary winding would
most likely go open-circuit, or the smoothing electrolytic cap or
bridge rectifier go open or short circuit....so I'm hoping that at
worst you get 0V at the output.

Can someone tell me the chances of a dangerous situation occuring.
What safeguard could I incorporate? Would a GFCI protector do the job?
Could I build a discreet GFCI into my circuit? Any ideas?

I intend to produce a commercial project powered with a wall adapter
that connects upto the human body.

Thanks

The regulations applicable to mains powered equipment for medical use
are very stringent, at least in the U.K.
Check your local regulations.
I doubt very much that an ordinary wall adapter would meet the
requirements.

 

[Lord Garth]

"royalmp2001" <royalmp2001@hotpop.com> wrote in message
news:1108567564.629415.104940@z14g2000cwz.googlegroups.com...

For safety reasons, I need to know what are the REALISTIC chances of
120V appearing at the output of a failed basic 12V wall adapter.

I would have thought most likely the secondary or primary winding would
most likely go open-circuit, or the smoothing electrolytic cap or
bridge rectifier go open or short circuit....so I'm hoping that at
worst you get 0V at the output.

Can someone tell me the chances of a dangerous situation occuring.
What safeguard could I incorporate? Would a GFCI protector do the job?
Could I build a discreet GFCI into my circuit? Any ideas?

I intend to produce a commercial project powered with a wall adapter
that connects upto the human body.

Thanks

Years ago, the phone company supplied some AC output wall warts to run
the dial lights in certain models of their phones. A recall occured because
these molded wall warts were, in some cases, overheating and becoming
potential fire starters.