On Thu, 20 Apr 2006 01:40:29 +0200, "petrus bitbyter"
wrote:


If you can get the right LEDs cheaper they are a good alternative. But LEDs
require verry low voltage and relative high currents. So a "standard" 20mA
LED will consume almost 2,5W to be dissipated in the serial resistor. I ever
made a circuit to use such a LED even at 230V but it takes quite some space
(and money). So to keep things simple, you'll have to use high efficiency
LEDs that require 2mA or even less. To make it really efficient you'll have
to add a bridge rectifier but four small general purpose diodes will do.
Sometimes someone advises to use one antiparallel diode but then you throw
away half of the light you can have for the same money.

---
Well, almost, but the three extra diodes aren't free. :-)

And then there's always:

120V----+--[LED]--+
| |
+--[LED]--+
|
120V-------[62k]---+


--
John Fields
Professional Circuit Designer