Paul TigerB6
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| posted on 17/3/08 at 08:09 PM |
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Perei 95mm LED lamps
I have a set of the above lamps as per Premier Wiring's website halfway down on this page.
Half
way down here
Now these lamps need resistor units but is it really essential to use the advertised ones at £9.95 a go??? Surely there must be a LocostBuilders
option??
cheers
Paul
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jos
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| posted on 17/3/08 at 08:12 PM |
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i havent got a resistor on mine
Who says you need a resistor?
.: Motorsport / motor racing circuit / track wall art Apex Traxs :.
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jos
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| posted on 17/3/08 at 08:14 PM |
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ah i see youre talking about the led versions arent you not the bulbed version slike wot ive got
.: Motorsport / motor racing circuit / track wall art Apex Traxs :.
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omega 24 v6
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| posted on 17/3/08 at 08:19 PM |
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looks like it's so that the flasher unit will be properly loaded. So just buy a time based unit instead of a load based unit. It'l cost
you but prolly not as much as 2 resistor units.
If it looks wrong it probably is wrong.
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JohnN
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| posted on 17/3/08 at 08:20 PM |
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Only the indicators need a resistor to use with existing flasher relay. I bought some from Maplin, can't remember the cost, but they were cheap.
High (comparatively) wattage in white ceramic blocks.... Values can be calculated to make the flashers draw the same current as 21 watt bulbs.
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Paul TigerB6
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| posted on 17/3/08 at 08:49 PM |
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quote:
Originally posted by omega 24 v6
looks like it's so that the flasher unit will be properly loaded. So just buy a time based unit instead of a load based unit. It'l cost
you but prolly not as much as 2 resistor units.
I'm an electronics / electrics numpty (just A-level physics to help me) so thats just gone straight over my head!! lol
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Paul TigerB6
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| posted on 17/3/08 at 08:54 PM |
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quote:
Originally posted by JohnN
Only the indicators need a resistor to use with existing flasher relay. I bought some from Maplin, can't remember the cost, but they were cheap.
High (comparatively) wattage in white ceramic blocks.... Values can be calculated to make the flashers draw the same current as 21 watt bulbs.
Yay - now thats the sort of answer i was hoping for off the forum. There are values on the rear of the lamps for the wiring which says the indicator
power should be 5.04 watts. Any ideas on the resistor i will therefore need??
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matt_claydon
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| posted on 17/3/08 at 09:39 PM |
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Yes, P= V*V/R
You need to dissipate another 15 Watts so
15 = 13.8*13.8/R (Assuming 13.8 volts)
So R = 190/15 = 12.7 Ohms.
I.e. you need a 12-13 (ish) ohm resistor rated to 15 watts.
Maplin do 10 watt resistors so I'd say use two of these in parallel to give 20 watt capacity. This halves the effective resistance so two of the
22R resistors in parallel giving 11 ohms would probably be near enough.
Edit: link - http://www.maplin.co.uk/module.aspx?ModuleNo=2181&doy=17m3
[Edited on 17/3/08 by matt_claydon]
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Paul TigerB6
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| posted on 17/3/08 at 09:45 PM |
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Fantastic - thanks Matt. At 40p each i guess we can afford 4 of those, 2 for each rear LED lamp.
Cheers
Paul
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RazMan
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| posted on 17/3/08 at 10:30 PM |
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Please PLEASE do not use the ballast resistors to bodge the flashing problem - use a proper LED flasher. The resistors can actually cause fires as
they often get very hot. They are simply dissipating all the power you are not using so why use the surplus power when you don't need to? (if
you see what I mean  )
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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Paul TigerB6
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| posted on 17/3/08 at 10:56 PM |
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quote:
Originally posted by RazMan
Please PLEASE do not use the ballast resistors to bodge the flashing problem - use a proper LED flasher. The resistors can actually cause fires as
they often get very hot. They are simply dissipating all the power you are not using so why use the surplus power when you don't need to? (if
you see what I mean )
So whats the solution if using standard front and side indicators with bulbs??
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omega 24 v6
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| posted on 17/3/08 at 11:47 PM |
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Ok a time based unit switches itself off and on independantly of any load applied. A normal unit has a bimetallic strip which as the load heats it up
breaks contact and as it cools down it remakes contact. etc etc. However it has to have the correct load or it will work to fast or to slow (like when
a bulb fails). The downside to a time based unit is that you DO NOT know when a bulb fails. This is a very grey area at the moment legally as you WILL
NOT have any warning of bulb failure.
That in mind you need something like this. It's not the one I was originally looking for but similar
Flasher
Do a search on here it's been discussed many times before with links to other products.
If it looks wrong it probably is wrong.
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Paul TigerB6
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| posted on 18/3/08 at 12:02 AM |
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excellent - thanks for that. Now i'm with ya and can understand more RazMans concern.
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02GF74
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| posted on 18/3/08 at 08:32 AM |
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the RazMan speaketh the truth.
see RFL3, RFL5 or RFL9
half way down this page
they are about a tenner inc VAT.
IMO rather pricey as I reckon one could make one for under a fiver; maplin do a flasher kit for that amount.
looky here - ebay cheaper still!! 
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Paul TigerB6
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| posted on 18/3/08 at 09:21 AM |
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aha - £5 from the States which is perfect (so long as the relay doesnt fail) and should get through customs without incurring VAT and duty as its such
a low value.
Thanks guys - problem solved it seems (so long as Martin has confirmed he does indeed want these lamps fitted to his car - otherwise i might just sell
them today on here)
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RazMan
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| posted on 18/3/08 at 10:40 AM |
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Yep, those led flasher units are the answer - just watch that you don't plug in normal bulbs by mistake or they will go pop.
Of course the full answer to the problem would be to fit leds all round ..... but then I would say that wouldn't I
On a cautionary note, check the pin connections are the same as the unit you are replacing - some swap around a bit and you just need to check.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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02GF74
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| posted on 18/3/08 at 12:04 PM |
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^^^^ I was astounded by how expensive these units are; a relay costs £ 2, the electronics about £ 2 if items bought seprately - mass production sould
reduce unit price to less about £ 3 yet they cost £ 10!!
(may need ot take apart a maplins £ 2 realy and see if that can be modified & have space for the electronics).
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RazMan
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| posted on 19/3/08 at 06:00 AM |
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Prices are still coming down as they become more readily available. Like anything new, there are always manufacturers keen to make a killing and move
onto the next new thing - just look how LCD TVs have plummetted in price.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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