Halcyon Scout / UK SL4 voltage questions...

[DNAXdiver]

battery tests not done under load are pretty useless since batteries return to there rrated volatage of as near as they can get when the load is taken off but put a load on and they drop right back down. you really want to test batteries figure out a way to read the voltage while they are under load.

leadweight once bubbled...
I took out the batteries on the SL4 and they tested at 1.4 v. Bulb was sllightly off center in the reflector, so I gently bent it back. This produced some improvement. What I am mainly noticing is this light is putting out a warmer color temperature than I remember it in the past.

Initially I thought the batteries were OK, but a fresh set cleared up everything. This leads me to believe that alkaline batteries producing nearly full voltage can have greatly decreased current if old.

 

[leadweight]

Dnax,

I think you solved my mystery.

 

[cadet diver]

Thought this might be relevant. I emailed UK a while back. This is the response I got.

Overdrive is a relative term.
Lamp Life, Color temperature, Brightness, Voltage and Current are are all
tied together or a mathmaticians say, "mutually dependent"
If you change one the other values change.

Lamps are really just a glowing piect of tungsten wire. You can change the
diameter and the length of the wire. The larger the diamerter, the more
current required to reach maximum brightness. The longer the wire, the more
voltage needed to meet maximum brightness. Maximum brightness occurs when
the wire finally gets so hot that it melts.

High Color Temperature comes at the expense of Lamp Life.
Long Lamp life comes at the expense of High Color temperature.

Raising the voltage decreases the lamp life and increases color temperature.

Generally lights with high color temperature sell better than lamps with low
color temperature. The are perceived as brighter.
Bright sells.

Only in the world of safety lighting is low color temperature and long lamp
life acceptable.

Underwater Kinetics wants to sell more lights than its competition. We
design lights withabout a 20-30 hour average life which allows us to have
Color temperatures in the range to 3000 to 3200 degrees Kelvin.

Is that over driving? Relative to what? Yes it is overdriving relative to
a 100 hour lamp of lower color temperature..

That is where the practice of connecting one of our SL4 lamps to 3 cells
rather than 4 cells began.
By lowering the voltage from 4 cells to 3 cells one extends the lamp life
considerably at the expense of brightness and color temperature.

Other manufactures have been know to really crank up the voltage on a lamp
for extreme brightness and color temperature. Lamp life has fallen to less
than 5 hours.

I hope this makes sense without going into the math of lamp design.

Just remember you can't get something for nothing.

Fred
Underwater Kinetics

 

[leadweight]

Interesting info from UK. I believe 3200K is roughly the color temperature of incandescent home lighting. Since our eyes are used to this level of somewhat amber color temperature, the light would not be preceived as not being blue enough.

Now does anyone know what the output of a SL4 bulb is on 4.5 volts?

 

[Scuba]

"Light sources with a lower color temperature (3500K or less) have a warm or red-yellow/orangish-white appearance. The light is saturated in red and orange wavelengths, bringing out warmer object colors such as red and orange more richly.

Light sources with a mid-range color temperature (3500K to 4000K) have a neutral or white appearance. The light is more balanced in its color wavelengths.

Light sources with a higher color temperature (4000K or higher) have a cool or bluish-white appearance. Summer sunlight has a very cool appearance at about 5500K. The light is saturated in green and blue wavelengths, bringing out cooler object colors such as green and blue more richly."*

*LightingfortheHome.com, provided as reference for quote.