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Pegleg



Member Since: 15 Apr 2010
Location: Deep in mid Wales
Posts: 3114

Wales 2008 Freelander 2 TD4 GS Manual Santorini Black
Bulb failure warning

Does anyone now if FL2 has bulb failure warning?

Some bulbs are FET driven and i'd have thought bulb failure monitoring would be a doddle.

Post #67811 5th May 2010 2:25 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4642

The current sensing / open circuit of the BTS443 FET transistors is not used in this application (FL2 circuits).
So the answer is NO, there is no bulb failure warning.

Post #67817 5th May 2010 4:45 pm
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Pegleg



Member Since: 15 Apr 2010
Location: Deep in mid Wales
Posts: 3114

Wales 2008 Freelander 2 TD4 GS Manual Santorini Black

Alex,
Thanks for your reply. It's rather sad that L/R didn't include bulb failure, it would have cost next to nothing and is a very useful and safe feature. Even my old R75 has bulb failure.
I think they've missed a trick here.

Post #67820 5th May 2010 5:17 pm
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Udash



Member Since: 23 Apr 2009
Location: manchester
Posts: 195

United Kingdom 2009 Freelander 2 TD4 HSE Auto Zermatt Silver

On the positive side it allows us to fit LEDs and xenons without worrying about errors. Freelander 2 TD4 HSE Auto
Zermatt Silver
Side Steps & Mud flaps

Post #67822 5th May 2010 6:54 pm
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W.D.C.A.P.H.



Member Since: 19 Feb 2010
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United Kingdom 2008 Freelander 2 TD4 S Manual Stornoway Grey

Always a silver lining to the cloud Thumbs Up We Don't Care About Pot Holes !!

Post #67826 5th May 2010 7:30 pm
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npinks



Member Since: 28 Jun 2007
Location: Ls25
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United Kingdom 

What's the reason for the small current that's goes round the lighting circuit?

It's been refered to as interior LEDs have a slight glow due to it even when not used Confused Former Mod/Member, with the most post & Chicken George Arch nemesis

Post #67827 5th May 2010 7:40 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4642

The interior lights have a "slow dim" feature.
For sure you've seen it: they didn't turn off suddenly, but slowly during 2-3 seconds.
This is also achieved by the use of a FET transistor which, when turning the lights off, slowly bring the GND (ground) connections of the interior lights up to the +12V power rail.
But because of the nature of the electronics and a few other things, that GND connection of the interior lights can't be brought up to the +12V (battery level) but about 0.7-0.8 volts lower (i.e. for a +12V battery level, to a 11.2-11.3V).
This voltage difference will make the LEDs shine very, very dim, while for a normal bulb, that 0.7-0.8V is way to low for shine.

Post #67833 5th May 2010 8:37 pm
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Pegleg



Member Since: 15 Apr 2010
Location: Deep in mid Wales
Posts: 3114

Wales 2008 Freelander 2 TD4 GS Manual Santorini Black

Alex,
I assume that the slow dimming of the interior light is achieved by using pulse width modulation?

Post #67836 5th May 2010 9:48 pm
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npinks



Member Since: 28 Jun 2007
Location: Ls25
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I knew the answer would be well explained

alex your worth a Bow down
Very Happy Former Mod/Member, with the most post & Chicken George Arch nemesis

Post #67837 5th May 2010 9:49 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4642

Pegleg wrote:
I assume that the slow dimming of the interior light is achieved by using pulse width modulation?

Yes. But to be honest, I've seen automotive dimming systems that use a plain and simple voltage regulation instead of a PWM.
Here, because the use of a FET with low ON resistance, is more easily to implement a PWM. Not to mention that the filament of a normal light bulb has a great luminous inertia and therefore there is no need for an LC filter.

Post #67896 6th May 2010 6:50 pm
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Udash



Member Since: 23 Apr 2009
Location: manchester
Posts: 195

United Kingdom 2009 Freelander 2 TD4 HSE Auto Zermatt Silver

With LEDs I thought that I might see bit of flickering during the dimming due to PWM but could not notice it, looks like its implmented well with very high rate PWM. Thumbs Up Freelander 2 TD4 HSE Auto
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Post #67960 7th May 2010 11:49 am
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xtattsbox



Member Since: 26 Jan 2010
Location: Suffolk
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United Kingdom 2008 Freelander 2 TD4 HSE Auto Stornoway Grey

Shocked

That is what I thought..... Hi Darling, I'll be home in 10 mins. If I'm not back, please read this message again...

Post #67966 7th May 2010 1:18 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4642

Over 60Hz you will hardly notice the flickering...
I know because I've made some signboards and over 60Hz you'll only notice the flickering in exceptional cases.

Post #67968 7th May 2010 1:33 pm
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Pegleg



Member Since: 15 Apr 2010
Location: Deep in mid Wales
Posts: 3114

Wales 2008 Freelander 2 TD4 GS Manual Santorini Black

In the next few weeks i'm going to investigate adding bulb failure to my FL2. I would really like to use a 'chime' from the I/P rather than a W/L. Think i'm gonna need some help from my old collegues at Gaydon to do this professionally.

Post #68753 18th May 2010 10:09 pm
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