Bi-colour LEDs

[ge_rik]

I've been trying to track down some 5mm red/white bi-colour LEDs for the IP Engineering Lollypop railcar build I'm presently engaged-in. The idea being that the front and rear lights will change colour dependent on which direction the railcar is heading.

I found 3mm red/white LEDs without problem and eventually tracked down some 5mm ones in the USA

http://www.unique-leds.com/index.php?target=products&product_id=1973 < Link To http://www.unique-leds.co...ts&product_id=1973

They seem reasonably priced at 32p each but will cost £5.85 p&p - which I suppose isn't too bad given they'll be transatlantic

Does anyone know a more and/or cheaper local source?

Rik

 

[nicebutdim]

Some companies don't keep a full product list online, which means they won't show up in google searches. It may be worth asking a couple of specialist suppliers directly such as https://www.google.co.uk/url?sa=t&r...=mwMCcZcS0eK3stDIF_2jaQ&bvm=bv.50310824,d.d2k < Link To https://www.google.co.uk/...;bvm=bv.50310824,d.d2k and see if they can help or hold them in stock.

 

[andyspencer]

Might be worth checking LED1.de. Still outside UK though...

 

[Gizzy]

I got some from Rapid Electronics in Colchester....

http://www.rapidonline.com/

 

[DoctorM]

You could try these

http://www.dccsupplies.com/shop/product_info.php?cPath=22_260_26_146&products_id=916

Slight overkill because they are tri coloured 5mm LEDs, Red/White/Green

 

[tramcar trev]

You could try these

http://www.dccsupplies.com/shop/product_info.php?cPath=22_260_26_146&products_id=916

Slight overkill because they are tri coloured 5mm LEDs, Red/White/Green

But they are ideal for an old style Hand lantern with the revolving lenses.....

 

[ge_rik]

Thanks guys

The DCC supplies tri-colour sounds a possibility. Just worked out however that the break-even point for overall cost is two LEDs and as I need a minimum of three it's marginally cheaper to ship them from the USA. I think I'll order 6 from the USA and have three spares.

Rik

 

[ntpntpntp]

Maplin usually have them as singles.

I'd expect there to be plenty on ebay in small quantities / cheap postage if that's all you need. Can't check to find examples while I'm @ work though.

I assume these are for analogue use not DCC? for DCC you normally need the rarer common-anode LEDs to match DCC function outputs - in which case try DCC-Supplies.

 

[PhilP]

Maplin usually have them as singles.

I'd expect there to be plenty on ebay in small quantities / cheap postage if that's all you need. Can't check to find examples while I'm @ work though.

I assume these are for analogue use not DCC? for DCC you normally need the rarer common-anode LEDs to match DCC function outputs - in which case try DCC-Supplies.

Do make sure they ARE common anode if for DCC!

 

[ge_rik]

Maplin usually have them as singles.

I'd expect there to be plenty on ebay in small quantities / cheap postage if that's all you need. Can't check to find examples while I'm @ work though.

I assume these are for analogue use not DCC? for DCC you normally need the rarer common-anode LEDs to match DCC function outputs - in which case try DCC-Supplies.

Do make sure they ARE common anode if for DCC!

No - it's OK they are for a battery build - but I do need common anode for that as the outputs from the Deltang controller are only single pole.
Rik

 

[ge_rik]

Maplin usually have them as singles.
I'd expect there to be plenty on ebay in small quantities / cheap postage if that's all you need. Can't check to find examples while I'm @ work though.

Tried Maplin and eBay. All sorts of other colour combinations but no 5mm red/white as far as I could see. Contacted an eBayer who does 3mm red/white and who specialises in railway stuff (and it happens is based in Chester, just down the road from me) and he says 5mm red/white LEDs are as rare as hen's teeth - and even the 3mm red/whites are increasingly harder to come by.
Rik

 

[Gizzy]

Tried Maplin. All sorts of other colour combinations but no 5mm red/white as far as I could see. Rik

I found the same at Maplins; no red/white LEDs there which is why I went to Rapid....

http://www.rapidonline.com/SearchResults?kw=5+mm+bi+colour+leds&srb=0&dir=0&cat=6244&icl=1&pg=1

 

[ge_rik]

BTW - sent an email to Unique-LEDs in the US of A thanking them for their excellent service and mentioning what I was using the LEDs for and got this reply

Rik,
Expect shipping to take a while, it usually does… I really would love to get into railroads, time and money says otherwise… Ohh I’m also from Barnsley !!!
John

Why do I get the feeling the world is shrinking?

Rik

 

[Nodrog1826]

So what is the circuit diagram for the common annode on DCC then?

 

[ntpntpntp]

DCC function common (+) to LED common anode. LED cathodes to DCC function outputs (F1, F2 etc.) as required. Normally only need 1 resistor in the anode side if only one colour is on at a time.

btw, for DCC make sure the bi-colour LED is a 3-wire common anode variety: there are 2-wire bi-colour LEDs which light one or other colour depending on the polarity applied.

 

[PhilP]

Only one resistor, unless you want to match apparent brightness, then you can use a different value resistor to each colour.

 

[ge_rik]

Only one resistor, unless you want to match apparent brightness, then you can use a different value resistor to each colour.

That's useful info - thanks
Rik

 

[DoctorM]

..... 5mm red/white LEDs are as rare as hen's teeth .....
Rik

If my original suggestion of using 5mm Red/White/Green Tripolar LEDs from DCCsupplies.com is too expensive,
I wonder if using a transparent White 5mm LED as the lens for a 3mm Red would be a cheap viable solution.

 

[ge_rik]

If my original suggestion of using 5mm Red/White/Green Tripolar LEDs from DCCsupplies.com is too expensive,
I wonder if using a transparent White 5mm LED as the lens for a 3mm Red would be a cheap viable solution.

Nifty!

Rik