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Newbie Help. 230v LED Circuit

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Dannyb100uk

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Hello,

I am trying to design a helpful (to me) Led lighting circuit.

Idea is - I have a couple of 230v circuits that have switchs in
Now as these circuits make i would like a little led light to light up.
This telling me that part of the circuit is working.

I really am new to this so parts and website's would be extremly helpful.

Thanks in advance

Dan

Added after 25 minutes:

Here's an example of what i mean. These aint cheap so wondered if there was a cheaper way of doing it.

http://www.echandlery.co.uk/230v-green-led-for-switch-panel-453-p.asp
 

Hi Dan,

Looks like those LEDS are designed to be connected directly to 230VAC.
So it is simply a matter of connecting them in parallel with any circuits you want
monitored. Probably a good idea to just buy them, especially if you have limited electronics experience. I looked at doing it with a diode and resistor but even at 10ma the resistor would need to be 23k at 3W. Would not reccomend doing it this way. Otherwise you would need a small transformer and bridge rectifier, capacitor and resistor which is more expensive than buying those LEDS.

Cheers,
Scanman
 

A more practical value for resistor that I have used and have worked for me is 47K 1/4W, or may be use 36K resistor and a diode in series with the LED and hook it directly to the mains (I normally do not use the diode and have never encountered a problem)
 

If you simply add a resistor in series with an LED and run it on mains, the reverse polarity half of the cycle will destroy it. Either fit a diode in series with the LED or in reverse parallel with it to prevent or clamp the reverse voltage. Most LEDs will only withstand 5V or so in the backward direction.

The one in the advert will already have a diode and resistor (possibly a capacitor) to limit the current and prevent reverse voltage damage.

Brian.
 

@betwixt You are right wrt the theory.

But I 'AM' using an led with only a resistor to test AC for a very Long time. It still works.

I am also using the same configuration as indicators on a switch board.
 

So there is a possibility? I Found another site but its a neon light instead of LED. Does a LED last longer? these only have approximate life span of 20,000 hours? **broken link removed**
Might be ok and cheap enough. I do Fancy still having a shot myself if anyone wants to do the maths for me and show me sites of what i need and how to lay it out.

Thanks. Dan
 

In my experience neon bulbs last "almost" forever.

Scanman
 

scanman said:
In my experience neon bulbs last "almost" forever.

Scanman
Click to expand...

Green ones don't. They slowly dim until you cannot see them. The orange ones do seem very long lived though.

Keith
 

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