Dashboard LED's

Brian Oblivion · Post by **Brian Oblivion** » 25 Feb 2004, 16:45

Hi,
Rossnum mentioned in a previous article about using LED's to replace blown dash bulbs, does anyone know where can you buy these?
Thanks
BTW now into my second week of zx ownership and I am blown away; best car I have ever driven and that includes my previous 306. So comfy, surefooted, quiet, quick Ahhhhhhhhh Bliss. Why aren't the roads full of them? I'm glad I'm one in the know.[8D][8D]
Only negative thing I can think of at the moment is the cack radio/cassette.

ActivaV6uk · Post by **ActivaV6uk** » 25 Feb 2004, 19:41

maplin for the LED's and you will need a correct resistor... i think those of us who are interested should group together and buy the LED's to bring the price down who would be interested in such a venture?
Andy

ZXturbo_Aura · Post by **ZXturbo_Aura** » 25 Feb 2004, 19:43

LED's arent that expensive, probably do the dash for £3, easily. CPC in Preston is cheap aswell, or Electronic supplier JPR, or RAPID. will the led's plug into the existing bulb holders?i weill get some and do mine and post all required info, work out the resistor value(s) by using the formula : V=IR V being voltage supplied, I current supplied and R resistance rearrange it to R=V/I simply divide the voltage supplied by the current
Dan

ActivaV6uk · Post by **ActivaV6uk** » 25 Feb 2004, 20:19

depends on the color of LED white ones are not cheep by any strech of the imagenation (£3 each!)

AndersDK · Post by **AndersDK** » 25 Feb 2004, 21:19

We had a discussion lately here :
http://citroenz.com/forum/viewtopic.php?t=502
Daylight/coloured LED's with adequate light intensity for dashboard should'nt be that expensive ???

rossnunn · Post by **rossnunn** » 25 Feb 2004, 22:07

Yeh Maplin is a good place to buy or CPC.
We put white LED's in a ZX and the dials are like a minty colour - look alwight tho as we've done the heater controls too.
I'm looking at converting mine to use Green LED's but am going to wait till some of the bulbs have blown.
Brian > come to Boston, Lincolnshire the place is crawling with them - still haven't sold mine tho.....reduced down to £450 now!!

Brian Oblivion · Post by **Brian Oblivion** » 25 Feb 2004, 22:29

Thanks rossnun, do you need a convertor for the bulb holder, and something to regulate the voltage for the LED or are they 12v dc compatible?
I can see two zx's in the car park next to me, perhaps when you buy a particular model you begin to see more and more of them?

davey · Post by **davey** » 25 Feb 2004, 22:56

LEDs....
you can buy allsorts... most colours, sizes, shapes, flashing and even viewing angle.
they norminally operate at 1.5 - 4v but ... you can get 12v ones with an integral resistor.
as mentioned earlier you need to put a series resistor in with most otherwise they will pop. when you buy, check out the spec ... maplin & the likes of cpc always give the maximum current rating for the device - typically about 20mA.
Therefore if the led max voltage is 1.5v ... and you car is 12v
then for above example: the voltage drop is 12v-1.5v =10.5v divide that by 20mA (0.02A)
=525. You need a 525ohm resistor (or nearest available size up).
LEDs are also polarity sensitive.
enjoy

uhn113x · Post by **uhn113x** » 26 Feb 2004, 00:15

A couple of points - we are talking about 14.5 volts, not 12. It is a good idea to put an 'ordinary' diode in series to prevent reverse polarity, which can kill a LED instantly. Most blue and white ones have a forward voltage of about 3.2 - you need to add 0.7 for the diode, say 4v.
14.5-4 = 10.5
10.5 / .020a = 525 ohms - 510ohms is neaarest preferred value

davey · Post by **davey** » 26 Feb 2004, 02:54

uhn,
no need for additional diode - as long as you have the series resisitor in place you will not blow LED, if u connect it wrong way round - it just wont work ....
....to clarify any confusion
the previous was only an example - use the diode specifications ie voltage and current rating given for the specific diode, and check whatever voltage u are going to drive it with in the cars case (i stand corrected 14.5v max) - always a good idea to go higher on resistor rather than lower - the light output lost aint much for a small increase in rsistor value and it gives u a margin of protection if the vehicle voltage creeps higher for any reason.
also may just save u taking that dash out again to replace all your nice shiny LEDs....

ZXturbo_Aura · Post by **ZXturbo_Aura** » 26 Feb 2004, 03:16

just a small note to uhn, an LED is a diode, like davey said, it simply wont work, its a right pain in the arse that they are polarity sensitive, keep makin mistakes in my Electronics A-Level work! lol!
Dan

Post by **martyhopkirk** » 26 Feb 2004, 03:45

Been reading this with interest, and other similar string.
Did a replo job on my last Ford using blue LED from CPC (dont live to far away and father in law has a trade account, so worked out reasonably cheap at £0.80 per led).
Now in the ford dash i wired all my LEDs in parallell from a switched live and fused them, but ran them through a 1kohm linear pot, which i mounted on the dash with a nice brushed alloy knob. whilst i could have popped them by winding the pot down to nil, i didnt (suppose in hind sight i should have just bunged in a 200ohm to be safe) but it made for quite a nice dash with variable brightness.
Whats put me off sorting the lamps on the citroen was it was a beach (phon) of a job to do the Fiesta dashboard, and the wiring looked like a plate of spaggetti, i gather the ZX dash doesnt come apart that easily also.
Still, may try it, may not. Currently running an external blue LED focused on the speedo which does the job ok, though external wires taped to dash with black insulation tape not to everybodys liking.

uhn113x · Post by **uhn113x** » 26 Feb 2004, 12:56

<blockquote id="quote">quote:<hr height="1" noshade id="quote">
just a small note to uhn, an LED is a diode, like davey said, it simply wont work <hr height="1" noshade id="quote"></blockquote id="quote">
Sorry, Dan and Davey - have to disagree here. If you look at the specs of LEDs, most have maximum reverse voltage ratings of about 5 or 6 volts. Some are as low as 0.5. If you connect an LED the wrong way round, it will be subjected to about 12.8 volts, as no current will flow initially. It may not blow instantly, but at best you will shorten its life.
I have done this many times and got away with it, but there again, you could cross a road blindfolded many times and not get killed - this does not mean that it is a safe thing to do!

Mike

uhn113x · Post by **uhn113x** » 26 Feb 2004, 12:58

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Now in the ford dash i wired all my LEDs in parallell from a switched live and fused them, but ran them through a 1kohm linear pot, which i mounted on the dash with a nice brushed alloy knob. whilst i could have popped them by winding the pot down to nil, i didnt (suppose in hind sight i should have just bunged in a 200ohm to be safe) but it made for quite a nice dash with variable brightness.
<hr height="1" noshade id="quote"></blockquote id="quote">
If anyone is doing this, you need a series resistor for each LED because of differences in Vf, they will draw different currents

Post by **martyhopkirk** » 26 Feb 2004, 23:52

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by uhn113x

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Now in the ford dash i wired all my LEDs in parallell from a switched live and fused them, but ran them through a 1kohm linear pot, which i mounted on the dash with a nice brushed alloy knob. whilst i could have popped them by winding the pot down to nil, i didnt (suppose in hind sight i should have just bunged in a 200ohm to be safe) but it made for quite a nice dash with variable brightness.
<hr height="1" noshade id="quote"></blockquote id="quote">
If anyone is doing this, you need a series resistor for each LED because of differences in Vf, they will draw different currents
<hr height="1" noshade id="quote"></blockquote id="quote">
Didnt think thst was an issue when using LEDs of the same type? (ie all 5mm Hyperbrite Blues in this case) Not that i mind, like i said, it worked but was fiddly and there was a lot of wiring.[:)]