Hella Micro DE's - Conversion to HID and Driving

[dlevett]

I'm in the process of 'moding' my Hella Micro DE's to HID (requires maken a new bulb holder since the HID H3's are different at the back to the standard Halogen H3's) - I'll post some details when I've succeeded.

On looking inside the Micro DE's, I notice that there is a 'plate'inside which blocks off 1/2 of the lens - hence why they are fog lights, and have such a good, sharp cut-off. The question is, has anyone tried removing this to convert them to driving lights?

I know what the first reply is going to be "if you want driving lights, buy driving lights" - but I have these fitted to the bike (touratech versions), and I don't want to buy some different ones and have to make up different brackets - then there's the cost (I am a Yorkshireman after all!).

 

[snoopy]

You're not the first to think of this, I was going to do it for the DR650 before I kept the GS. Problem is the units are welded so it would be immensely difficult - especially given they are magnesium.

 

[rc mad]

I've looked at doing the same thing. There is no way to get into the unit that i can see, short of taking a grinder to it

 

[Wizard]

You're not the first to think of this, I was going to do it for the DR650 before I kept the GS. Problem is the units are welded so it would be immensely difficult - especially given they are magnesium.

I've looked at doing the same thing. There is no way to get into the unit that i can see, short of taking a grinder to it

Oxy-acetylene torch should sort it

 

[ballistic]

Oxy-acetylene torch should sort it

Magnesium... Oxy-acetylene torch...?
Wasn't magnesium the stuff that burst into bright flames when I was at school?

 

[Wizard]

Magnesium... Oxy-acetylene torch...?
Wasn't magnesium the stuff that burst into bright flames when I was at school?

 

[dirtydog]

Magnesium... Oxy-acetylene torch...?
Wasn't magnesium the stuff that burst into bright flames when I was at school?

Magnesium oxide certainly did...

 

[dlevett]

I'll have a close look, it looks like I'll be sticking with the 'fog' pattern then!

I'm quite happy with that, as I use them in tandem with the dipped beam for people to see me, rather than me to see them, in traffic.

 

[snoopy]

You could always electrician tape them

 

[dlevett]

I've finished the mods to the first one to hold the HID lamp. It turned out not to be too bad a job really - other than the Torx bit to remove the existing lamp holder (3 screws), all I needed were drills, tin snips, a bench gringer and a dremel.

I used 0.5mm stainless steel (because that was what I had), but it may be better to use 1mm aluminium.

My mod involved making 3 pieces:
- one to replace the existing lamp holder
- one as a spacer for the thickness of the HID lamp base
- one to go behind the base to hold the lamp in

The existing 3 screws hold all 3 pieces in, and everything appears absolutely secure.

I've only got to duplicate the arrangement for the other one.

I'm still in two minds whether to go 50W HID or 35W HID.

With the 50W HID in, the Micro DE seemed to be getting hot (though I've never 'felt it'after the 55W Halogen has been running for a while). To test, I was running it from one of those 'jump start'units - therefore only 12V at most - and measured the current at about 4.3A (51.6W if it was truely 12V - more likely to be about 11.6V by the time I got the ammeter set up). The base of the 50W HID bulb is plastic - but I suppose it is made to 'take the heat'.

 

[bonox]

50 watts is 50 watts - doesn't matter where you get it. The difference with the HID setups is that you get more lumens for the same input power - a 50 watt HID capsule will dissipate the same heat as a 50 watt filament lamp. (correct for the energy consumption by the ballast which is outside the lamp)

 

[dlevett]

No arguement that 50W is 50W. I checked the current to ensure that the HID Lamp was drawing approx. 50W.

My concern with the HID lamp is that the base of the bulb is plastic whereas the base of a 55W Halogen is metal (it has to be since this is the negative contact for the bulb) which will both dissipate and withstand the heat better.

Once tested to ensure that the current draw equated to 50W, I didn't have a concern with the construction of the Hella Micro DE's, only with the lamp base which, because I used stainless steel to make the new lamp holder, will get to the same temperature as the housing.

 

[bonox]

proper plastics are pretty good with temps higher than we can touch. Most people are just used to the superlightweight polypropylene type plastics that food containers are made from.

If the lamp came with a plastic base, I fail to see the problem...

What am i missing?

 

[dlevett]

Bonox,

I don't think you are missing anything. My only concern is around the plastic base and the mod I have fabricated to hold the lamp.

With a standard H3 lamp, the 'front' of the base rests against a metal plate (for the -ve return) and the lamp is held in with a 'spring clip' hence the base is not fully enclosed.

The modification I have made 'sandwiches' the HID lamp base between 2 stainless steel plates (with a 3rd as a 'spacer' to account for the thickness of the base and to stop the lamp rotating).

Therefore my only concern is that there is no 'air-flow' around the plastic base, with the possible issue of heat degredation but, is you said, if it is made like that, it should be up to the job.

 

[bonox]

ahh - by far and away the vast portion of heat comes from the region of the capsule where the arc lies. Thermal transfer over the plastic base would contribute sod all imo. What heat there is, the lamp base will tolerate based on my experience of the same.

*thumbsup*

 

[Cole]

50 watts is 50 watts - doesn't matter where you get it. The difference with the HID setups is that you get more lumens for the same input power - a 50 watt HID capsule will dissipate the same heat as a 50 watt filament lamp. (correct for the energy consumption by the ballast which is outside the lamp)

I believe thats not quite right ... 50 watts is 50 watts of ENERGY, not 50 watts of heat. A HID light turns more of the 50 watts of energy into light (than a halogen), ergo it turns LESS of that energy into heat (the amount of energy is fixed - only into what forms it is transformed varies. The more that goes into light, the less that goes into heat)

A filament is a pretty inefficient system of turning 50 watts of energy into light, because it uses most of that energy to produce wasted heat. A HID uses more of the energy to produce light, and as a result less is wasted as heat.

So a 50 watt HID does produce less heat than a 50 watt filament as a byproduct of the light making process.

Similarly inside your house, a 50 watt flourescent light is also dramatically more efficient than a 50 watt filament lamp at creating light rather than heat, so that too would be a lot cooler.

How hot exactly obviously depends on the cooling afforded by the lamp, but I have seen figures that imply the temp inside a lamp housing with a HID in it is approximately half that of a similar wattage Halogen bulb

 

[bonox]

while HID is more efficient than filament lamps, they are still fairly lousy overall. As a first approximation, it is safe to say that any lamp housing designed for a 50w filament lamp is safe for a 50w lamp of any description.

One might also add that the HID lamps move a significant portion of total energy consumption outside the lamp housing - the ballast for a 35W lamp often consumes another 7watts - it's just moving the heat source elsewhere.

 

[dlevett]

Energy can neither be created nor destroyed - or so my Physics Teacher said (I think, it's a long time ago!).

Therefore 50W is 50W is 50W and it is all dissipated somewhere.

With a Halogen Lamp (assume 50W), a large portion is dissipated as heat and some is used to produce light which is then dissipated outside of the light fitting.

With a HID, the total energy consumed is split up. Some is consumed in the ballast as losses (equates to heat), some is dissipated as heat in the lamp(/to the sorroundings - i.e. light fitting) which is, in turn, dissipated to the surroundings, and some is converted to light and is dissipated outside of the fitting as light (obviously a higher proportion of the total energy produces light - hence the higher light output and cooler running) = greater efficiency.

This is why you get a similar light output from a 15W compact fluorescent as you do out of a 60W incandescent lamp (more of the energy is converted to light) and why you can touch a compact flourescent lamp, but you'd only touch an incandescent lamp once! LED's are approximating the ideal light source (that we've found so far) - all the energy consumed is converted to light, and virtually none as heat (unless you size the resistor incorrectly and then you only generate heat for a very short time!)

I am not entirely sure whether a 50W HID is 50W total power (including ballast losses) or 50W lamp power i.e. say 55W total power.

 

[snoopy]

Did you have any luck drilling them for running lights?