Re: HELP to make LEDs work with AC current

On Oct 8, 1:47 pm, Mark Main <em...@xxxxxxxxxxxx> wrote:
I have a transformer that is reducing the AC supply voltage down to
25.5VAC, which connects to a thermostat that connects to a Honeywell
water valve for my home boiler system, which then completes the
circuit back to the transformer. I don't see an amperage limit marked
on the transformer--it's about baseball size, so it's not small.

Only 1 of the poles of the relay is used and I would like to use the
other poles of the relay switch to power a red LED (either a standard
LED or a Bi-Polar LED).

This is my home, safety is top of the list (e.g. in my research I've
seen some people offer designs that don't use resistors with the LEDs
or they connect diodes straight across the power supply, both of which
don't seem like they maximize safety).

I want the design to still be safe when one of the parts does
eventually fail.

I need help with the design, and I'd especially like to know the
formulas that were used in the design because I eventually want to
create some LED lighting under my kitchen counter that uses 110V AC...
So if you can help me calculate how I alter the design for 110V vs.
this current 25.5V design that would be great.

I'd like to know how to do this using standard LEDs and also how to
also do it using the bi-polar LEDs.

Thanks for any help... I'm new and learning and have only done a few
basic projects so far.


From Google:

http://www.marcspages.co.uk/tech/6103.htm
http://www.turbokeu.com/myprojects/acled.htm

The usual disclaimers apply; use at your own risk; I am NOT an
electrical engineer qualified to make assessments re: electrical
safety.

Folks, any comments on the safety of those circuits? Electronic
current-limiting countermeasures recommended?

Michael
.

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