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.


Even simpler (no bridge rectifier):
http://www.elecfree.com/electronic/mains-voltage-indicator-with-a-led/

I recall seeing a schematic similar to the above, but I just can't
find the exact link anymore...

Michael
.

Relevant Pages

  • Re: HELP to make LEDs work with AC current
    ... circuit back to the transformer. ... 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 ... I need help with the design, and I'd especially like to know the ...
    (sci.electronics.design)
  • Re: High current LED driver circuit
    ... Does anyone have some simple circuit design that will handle 16 high ... power leds from 220V power source? ... transformer winding you just connect your LEDs via small coil. ... can be destroyed by voltage spikes in power grid. ...
    (sci.electronics.design)
  • Re: Programmable IR LED Flasher Circuit -- How to Build?
    ... death to the 9V battery. ... Design with AA cells. ... The one that I've used has 3 LEDs in it. ... so a pattern of flashing would be dumb. ...
    (sci.electronics.design)
  • Re: Programmable IR LED Flasher Circuit -- How to Build?
    ... death to the 9V battery. ... Design with AA cells. ... The one that I've used has 3 LEDs in it. ... AA cells and a boost converter instead of the 9V battery. ...
    (sci.electronics.design)
  • Re: ? on small battery operated fluorescents
    ... emmitter/collector voltages etc.) but it's still not a late design. ... flashlight and a fluorescent tube down the side, ... then the body of the light becomes the heatsink ... When it comes to implementing a driver board and LEDs, ...
    (sci.electronics.basics)