On Thu, 22 Mar 2001 22:07:53 -0500, you wrote:

>Can you make a power supply that outputs 5V at 50-100ma that connects to=
 120AC line with no transformer, the idea needed is for a very cheap =
device. It would need to be at least CSA/UL approvable.
>
>What comes to mind is a cheap 100ma 78L05 5V reg, but whats needed =
between it and the AC?
>
>What about isolation issues?
>
>Lots of issues here I am sure.
>
>Thanks,
>Richard.
At this current level a transformerless PSU is not really practical -
small transformers are very cheap, and will be cheaper than any other
method except maybe a HUGE resistor and a lot of heat.
Using a transformer will also save a lot of approval costs.

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