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Re: 7 inch budget lucas-style round headlights

Posted: 27 Nov 2014, 22:04
by CJH
itchyfeet wrote:I like the daytime look of the lights you got :ok

Yes, it's quite a nice look, although I haven't actually tried them in the daylight yet - that was a night time photo. They're very low powered - there's two semi-circular light pipes, with an LED at each end, so each lamp has only four LEDs. If they show up in the daylight I might be tempted to wire them up as DRLs. I don't think it would cause a problem to have an ignition-controlled live AND the switched live connected up at the same time, would it? I guess it would mean the switched side of the dashboard switch would be live whenever the engine was running, but I don't believe that would cause a problem.

Re: 7 inch budget lucas-style round headlights

Posted: 27 Nov 2014, 22:20
by CovKid
Strangely I was looking at LED strips for sidelights this morning. I do like using them as they consume so little and the light carries a long way - ideal in Winter months. The only downside with LEDs is although they reportedly last a long time I've seen several burn out prematurely and if the unit is sealed, you're a bit stuffed. Can you get into those ones Chris or are they totally sealed? I was going to go for strips as they're replaceable.

Re: 7 inch budget lucas-style round headlights

Posted: 27 Nov 2014, 22:36
by CJH
Totally sealed as far as I can see Ralph. Yes, it's not like a replaceable bulb. I guess if the LEDs fail I might be tempted to try the oven or hairdryer trick to soften the glue, although with everything made of plastic that could end in tears! If they'd come apart, then I'm sure there are brighter halo rings on the market that could be transplanted in there.

Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 06:20
by itchyfeet
What I meant ws I like the daytime look of the lamps without the sidelights on, although I hadn't realised they were LED
You can see right inside, gives them depth..

What kills LEDs (and thier current limiting circuit) appart from poor quality manufacture is surges caused by overvoltate in one direction or reverse polarity, I know quite a bit about mains connected LEDs surge sources but in a vehicle my guess is this could be caused by many things including static and induced spikes from ignition.

With mains surge protection is largely down to Metal Oxide Varistors, I cant see why you should not fit them, they basically short on over voltage, you would only need one on a dc system in differential mode i.e. between 12v and chassis

Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 07:03
by CovKid
Exactly. Even in normal running, 12.5v can be much more than that at times and I'm not sure that does LEds much good.Like they say though, nothing lasts forever. In any event the lights you chose look great Chris. Let us know how they fare in the dark.

Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 08:42
by ghost123uk
Or a 15V Zener diode.

Florescent light circuits and cheap inverters can introduce high voltage spikes on vehicle wiring.

At one time I used a home made (LM3914 based) LED bar graph type voltmeter in the van. Whenever I switched the florescent light on (long since replaced with warm white LED strip) it sent the meter off the scale.


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Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 08:44
by CJH
itchyfeet wrote: With mains surge protection is largely down to Metal Oxide Varistors, I cant see why you should not fit them, they basically short on over voltage, you would only need one on a dc system in differential mode i.e. between 12v and chassis
Any idea how I would go about selecting the right specification?

CovKid wrote:Exactly. Even in normal running, 12.5v can be much more than that at times and I'm not sure that does LEds much good.Like they say though, nothing lasts forever. In any event the lights you chose look great Chris. Let us know how they fare in the dark.

This sounds like a good reason NOT to wire them up as DRLs after all (to avoid starting surges) although I think during starting I'd get under-voltage rather than over-voltage. And even if I leave them to work only from the dashboard switch there's no guarantee that I won't start the van with them already turned on. I know it's not fully light yet, but they still look good as DRLs.

I measured the current draw, and each side draws only 50mA (less than a sixth of the 4W sidelight bulbs in the originals - not bad given how similar they look in brightness), so between them they'll only draw 0.1A. That means I could leave them on for at least a week before the battery would start to feel the strain. So maybe I'll leave them as 'manual' DRLs, safe in the knowledge that if I forget to switch them off it's not going to be a problem for one day.

Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 09:51
by itchyfeet
I will have a look for a MOV, Maybe Ghost can help too if he is reading?
you need a working voltage greater than an alternator charging voltage.

As for DLR wire them to the x relay track which gets switched off for starting.

Surges can be caused when motors switch
These are transient very short duration voltage spikes caused when magnetic fields collapse ( the same principle used to generate sparks in a coil), having the engine at the back helps as the wires impedance is greater.

Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 10:09
by ghost123uk
Here is a suitable Zener that will safely dissipate any Voltage over 15 Volts in your system = http://uk.rs-online.com/web/p/zener-diodes/2265221/" onclick="window.open(this.href);return false;


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Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 10:19
by itchyfeet
How is that connected John?
will that protect against voltage spikes in both directions as I think a MOV does?

Re: 7 inch budget lucas-style round headlights

Posted: 28 Nov 2014, 11:19
by ghost123uk
Simply bolts to a nice bit of earth (bodywork) and a live feed to the top (then shrink wrap insulated).

Any voltage over 15V gets shunted to earth.

I see what you're getting at re possible negative high voltage spikes though.
I suppose that could happen, and then you would be right, a Metal Oxide transient suppressor would be more appropriate :ok

Re: 7 inch budget lucas-style round headlights

Posted: 29 Nov 2014, 01:10
by CJH
itchyfeet wrote: Have been looking for a circular flat ring that you can screw to the adjuster ring, you can then drill holes and mount defender bezels unmodified, seen some candidates but nothing certain yet.

Not a cheap option by any means, but I've just stumbled upon this aftermarket frame from GoWesty.

It's not easy to tell from the photos, but it looks as though it includes a chrome bezel as well as a new galvanised mounting frame. I can't see whether the adjuster ring has the recesses for the Lucas lugs.
Image
Image There's a better version of this photo on the web page linked above.

Re: 7 inch budget lucas-style round headlights

Posted: 29 Nov 2014, 07:23
by CovKid
Bit of a sledgehammer to crack a nut though. :D

Re: 7 inch budget lucas-style round headlights

Posted: 29 Nov 2014, 08:35
by nicktennear
Is it necessary to fit relays before upgrading to h4 bulbs? If I do I'll probably use the Landy kit but if I can get away without it I will. Which is easier? Relay upgrade or replacing melted switch? :wink:

Re: 7 inch budget lucas-style round headlights

Posted: 29 Nov 2014, 09:11
by ghost123uk
nicktennear wrote:Is it necessary to fit relays before upgrading to h4 bulbs? If I do I'll probably use the Landy kit but if I can get away without it I will

It's not "necessary" but it is highly recommended.

And as for "Relay upgrade or replacing melted switch? " it's not "or" is it, the melted switch has to be replaced, the relay is optional (and will prevent any future problems with the switch as well as improving the lights).

Note :- If buying new H4 bulbs, go for the "NightBreaker" ones Like these, they are better than the standard H4 and not much dearer.