Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: Marks DTM Calib on 11 January 2009, 15:45:39
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.....which might be of interest to some.
Wondered where the lack of light output on the projector lamps was and why it was occuring.
Today I made some measurements on the electrical feed to the bulbs with the engine not running (lower voltage so worst case scenario)
Battery voltage - 12.6V
Bulb Voltage - 11.1V
Bulb resistance - 3 ohm
Calculated watage - 41W!
Its clear that we need to address these volt drops to get max light output as the bulbs are running at 23% less than thier rated amount!!
So, on the 0v side I found a volt drop of 470mV when measured between the bulb body and 0V terminal of the battery. I looked further and 300mV of this is lot across the lucas style terminal that connects the 0V feed to the bulb mount!
So I soldered the terminal to the body and we got:
Battery voltage - 12.6V
Bulb Voltage - 11.4V
Bulb resistance - 3 ohm
Calculated wattage - 43.3W!
Next stop was to look at the positive side.....the volt drop here was close to 1V!
Again, 200mV of this was across the lucas type connector to the back of the bulb.
This cant be soldered as it would affect the ability to change the bulb so I removed the connector and fitted a nice tight new one.
Battery voltage - 12.6V
Bulb Voltage - 11.6V
Bulb resistance - 3 ohm
Calculated wattage - 45W
The rest of the volt drop is clearly a result of the wiring and switch so I may try adding a relay switched feed to the headlights.
Key thing here is though that a small amount of work has yielded a 10% increase in theoretical light ouptut!
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:y
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without having to fit overated illegal bulbs :y nice one
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i got some ov them, 100 watters :o is that common practice?
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i got some ov them, 100 watters :o is that common practice?
No & it's very naughty!
-
.....which might be of interest to some.
Wondered where the lack of light output on the projector lamps was and why it was occuring.
Today I made some measurements on the electrical feed to the bulbs with the engine not running (lower voltage so worst case scenario)
Battery voltage - 12.6V
Bulb Voltage - 11.1V
Bulb resistance - 4 ohm
Calculated watage - 44.4W!
Its clear that we need to address these volt drops to get max light output as the bulbs are running at 10% less than thier rated amount!!
So, on the 0v side I found a volt drop of 470mV when measured between the bulb body and 0V terminal of the battery. I looked further and 300mV of this is lot across the lucas style terminal that connects the 0V feed to the bulb mount!
So I soldered the terminal to the body and we got:
Battery voltage - 12.6V
Bulb Voltage - 11.4V
Bulb resistance - 4 ohm
Calculated wattage - 45.6W!
Next stop was to look at the positive side.....the volt drop here was close to 1V!
Again, 200mV of this was across the lucas type connector to the back of the bulb.
This cant be soldered as it would affect the ability to change the bulb so I removed the connector and fitted a nice tight new one.
Battery voltage - 12.6V
Bulb Voltage - 11.6V
Bulb resistance - 4 ohm
Calculated wattage - 46.4W
The rest of the volt drop is clearly a result of the wiring and switch so I amy try adding a relay switched feed to the headlights.
Key thing here is though that a small amount of work has yielded a 5% increase in theoretical light ouptut!
please correct me if wrong ,,, but would you not gain more wattage if the volts were at alternator output, i.e 13v ish? :-?
-
.....which might be of interest to some.
Wondered where the lack of light output on the projector lamps was and why it was occuring.
Today I made some measurements on the electrical feed to the bulbs with the engine not running (lower voltage so worst case scenario)
Battery voltage - 12.6V
Bulb Voltage - 11.1V
Bulb resistance - 4 ohm
Calculated watage - 44.4W!
Its clear that we need to address these volt drops to get max light output as the bulbs are running at 10% less than thier rated amount!!
So, on the 0v side I found a volt drop of 470mV when measured between the bulb body and 0V terminal of the battery. I looked further and 300mV of this is lot across the lucas style terminal that connects the 0V feed to the bulb mount!
So I soldered the terminal to the body and we got:
Battery voltage - 12.6V
Bulb Voltage - 11.4V
Bulb resistance - 4 ohm
Calculated wattage - 45.6W!
Next stop was to look at the positive side.....the volt drop here was close to 1V!
Again, 200mV of this was across the lucas type connector to the back of the bulb.
This cant be soldered as it would affect the ability to change the bulb so I removed the connector and fitted a nice tight new one.
Battery voltage - 12.6V
Bulb Voltage - 11.6V
Bulb resistance - 4 ohm
Calculated wattage - 46.4W
The rest of the volt drop is clearly a result of the wiring and switch so I amy try adding a relay switched feed to the headlights.
Key thing here is though that a small amount of work has yielded a 5% increase in theoretical light ouptut!
please correct me if wrong ,,, but would you not gain more wattage if the volts were at alternator output, i.e 13v ish? :-?
I think the reason he has done the test without the engine running is to highlight the areas with voltage drop. Obviously with the engine running the voltage drop will still occur, but will be more difficult to identify the problem areas.
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I need to work with a minimum number of variables.
The resistance of the wires will be constant and wont change with the engine running (which is what we are checking effectively here).
It would appear from the measurements that to get max rated wattage out the bulbs you need about 13V across them.....we are still a little short of this!
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I need to work with a minimum number of variables.
The resistance of the wires will be constant and wont change with the engine running (which is what we are checking effectively here).
It would appear from the measurements that to get max rated wattage out the bulbs you need about 13V across them.....we are still a little short of this!
Even at running voltage of 14ish, your not going to be much over 12v at the bulb, which isn't that great.
I'm guessing that as most 12v cars are going to be running at 14v, the bulbs are actually designed for 14v running?
Anything to get less loses in the wiring and better voltages at the bulb have got to be :y
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i got some ov them, 100 watters :o is that common practice?
No & it's very naughty!
;) oh well ::) ::)
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I need to work with a minimum number of variables.
The resistance of the wires will be constant and wont change with the engine running (which is what we are checking effectively here).
It would appear from the measurements that to get max rated wattage out the bulbs you need about 13V across them.....we are still a little short of this!
Even at running voltage of 14ish, your not going to be much over 12v at the bulb, which isn't that great.
I'm guessing that as most 12v cars are going to be running at 14v, the bulbs are actually designed for 14v running?
Anything to get less loses in the wiring and better voltages at the bulb have got to be :y
my thoughts too, - im thinking there designed to operate at typical running voltages, and the designes resistance, i.e wire diameter/fuse rating
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i got some ov them, 100 watters :o is that common practice?
No & it's very naughty!
Maybe so. But before HID etc police sars used to fit 130 watt bulbs, so I dont understand, if it's ok for plod, then why not for all road users.
Lets face it, rules is rules. :-X
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well done mark, i might have to have a look at doing mine too.
cheers :y
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For info....it would appear that most manufacturers use a test voltage of 13.2V....this also ties in with the measured resistance!
So you only get 55W output at 13.2V at the bulb terminals
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Here is a little graph to show how a small drop in supply voltage has a big effect on bulb operating wattage (I2R)
(http://i23.photobucket.com/albums/b394/Marks_DTM_Calib/Wattagegraph.jpg)
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So making the connections and wiring very low resistance - eg thicj cables, and switched with a quality relay, does this mean you will drastically shorten bulb life (if you could get near to 14v across bulb?
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Possibly.....the bulbs as stated appear to be rated at 13.2V....so this would be about the optimum I would say.
Not an issue with HID's as they use a stabilised supply thanks to the use of a DC-DC converter
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i got some ov them, 100 watters :o is that common practice?
No & it's very naughty!
Maybe so. But before HID etc police sars used to fit 130 watt bulbs, so I dont understand, if it's ok for plod, then why not for all road users.
Lets face it, rules is rules. :-X
100w or 130W is approx twice the current. Will the relay, wiring & fuse stand that?
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Possibly.....the bulbs as stated appear to be rated at 13.2V....so this would be about the optimum I would say.
Not an issue with HID's as they use a stabilised supply thanks to the use of a DC-DC converter
Yup, was only thinking about halogens, and not thinking about any car in particular (both mine have reasonable HIDs, and the Rover has pretty good lights), just thinking around the theories :y
Saying that, might be worth looking into improving that main beam on the Omegas, esp if I put chavvy bulbs in to match the HIDs?
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i got some ov them, 100 watters :o is that common practice?
No & it's very naughty!
Maybe so. But before HID etc police sars used to fit 130 watt bulbs, so I dont understand, if it's ok for plod, then why not for all road users.
Lets face it, rules is rules. :-X
100w or 130W is approx twice the current. Will the relay, wiring & fuse stand that?
Not tried on Omega, but never had issues with other cars...
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MDTM - as the wiring/switches/contacts/connectors etc age, is it likely the resistance will increase? Is this another reason why older Omegas seem to have poor lighting?
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Possibly.....the bulbs as stated appear to be rated at 13.2V....so this would be about the optimum I would say.
Not an issue with HID's as they use a stabilised supply thanks to the use of a DC-DC converter
Have u fitted HID's yet? ;)
Omega projectors are useless with standard filament bulbs >:(
Makes me wonder why they fit projectors really......
Ive got standard filament bulbs, non projectors on my Viano and they are great....bright....do the job fine.....so why buggar about with projector lenses?? :-/ :-/
Interesting reading btw :y
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i got some ov them, 100 watters :o is that common practice?
No & it's very naughty!
Maybe so. But before HID etc police sars used to fit 130 watt bulbs, so I dont understand, if it's ok for plod, then why not for all road users.
Lets face it, rules is rules. :-X
100w or 130W is approx twice the current. Will the relay, wiring & fuse stand that?
Not tried on Omega, but never had issues with other cars...
I agree with TB, have tried all sorts of bulbs over the years. 100/55. 100/80 and even 130/100 never had any issues.
Would be interesting to know the cable size and therefore work out what the wiring can/could cope with.
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Cable size is easy....
its 1.5mm stranded....this will take around 5 amps.....which gives just over 60 watts.
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Interesting.. :y
my ex car was weak on the lights also..after an upgrade to 100W
it became really good..
And miggy with original lights (even with new head lights-I changed to new) was a shame for that good car.. So definitely HID..
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On a previous car I had 460w on full beam with the driving lights as well
160w total dip
And I ran relays from the battery
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On a previous car I had 460w on full beam with the driving lights as well
160w total dip
And I ran relays from the battery
yep..for upgrades relays necessary..Was Bosch if I remember correct..and never had problem..