On 01/02/2014 20:51, fred wrote:



Now consider dissipation in the res with led on:

You have gone for a 470nF dropper which gives a hefty 35mA rms current.
This will be pushing 5W in each resistor which is really too much (even
with a 10W res, it would be too hot to touch). In addition, you will be
running at a peak led operating current of 50mA which again is too much.



4. IMO, it would not be safe to mount the LEDs in a metal panel (even if
earthed), the insulation will not have been specified for mains use. Use
a plastic panel and mount so that even if damaged, the LED junction
would be some way behind the front face of the panel.


Are you sure you don't want to scrap it all and use some skinny neons ;-)



Box will be all fully insulated nylon ...


Never use neons ... what would cct look like with these .... although I
would prefer to use what I just bought .... (if it is possible)

The whole reason for going to capacitor dropper was to avoid dissipating
heat in resistors which many of the simple ccts do.

Just so annoying I followed the design as per here ....
http://www.marcspages.co.uk/tech/6103.htm

(I have had contact from page owner he insists with 220R it works fine,
but for additional reliability it could be increased to 680R )

--
UK SelfBuild: http://uk.groups.yahoo.com/group/UK_Selfbuild/