3 level PT Apex WITHOUT 5mm LEDs!

Since getting into Luxeon LEDs, I've never thought 5mm LEDs were any good for high power outputs.

(Blah, blah, blah ON)
Recently I got a PT Apex headlamp (thanks Brooks ) and wasn't too pleased to realized that the 5mm high mode was brighter than the main LED low mode. Besides that, the main beam sucked. (IMHO)

Of course, I went ahead and did the Seoul (USVOH) mode with a cut down 20 mm Kathod reflector. The output was outstanding with the brightest mode a tad dimmer than my Q5 moded L2D on turbo. I still wasn't satisfied... (Are we ever?)

Today, I had nothing to do so opened up the apex again and checked weather all the 5mm LEDs +ve and -ve leads were connected together (parallel). The continuity meter said that they were though I couldn't visually verify. I removed one LED and made the checks again and got the same results. I also checked voltage and as expected, voltage across the 5mm LEDs were always higher than voltage across the Seoul (current regulated).

Polking around in there, I also discovered that +ve to the 5mm LEDs was the same as +ve to the Seoul while -ve to the Seoul, 5mm LEDs and ground were all different. (No continuity)

I decided to take the plunge :sick2: and remove all four 5mm LEDs (checking continuity again) and connect via one wire -ve from the 5mm LED circuit to -ve of the Seoul.

When putting in the last cell :candle: , I looked for any evil puffs of smoke but saw none. Pressing the main switch, (spot) the LED lit up! :huh: Pressing it again, the LED dimmed as before. When I pressed the 5mm switch, the Seoul lit up! Eureka! Pressing it again, the Seould dimmed considerably and a thrid press made it strobe. :rock:
(Blah, blah, blah OFF)

NOTE: I'll refer to the (former)5mm LED modes as '5high' and '5low' while I'll refer to the Seoul LED modes as 'spot high' and 'spot low'.

With this mod, 5high is very slightly brighter (I'd guess 10-15%) than spot low so effectively, they are the same brightness giving this moded light three levels plus strobe.

In comparison to my moded EOS (Seould USVOH, 17mm IMS), EOS high is the same brightness as the Apex's 5high and the Apex 5low is in between the EOS's med and low modes.

WRT durability, I've had the Apex on 5high for a full hour without any effects and used it for another 20 mins after that on 5low problem free.

Again, all I did was remove the four 5mm LEDs and connected a wire from 5mm -ve to Seoul -ve and that's it!

I'm super happy with this mod.

eebowler

Hello eebowler
Your mod of the apex is IceHot dude!
Would you know the current drain now for all the levels.
\ I have not seen any apex current drain data for the various
modes.
Mostly curious about current drain of 5low now in your mod'd Apex.
thinking about how many night hiking hours it'll give...

The light would not come on if I used the mA scale, so all readings were made with the 10A scale. I trust meter 2 more than meter 1.

Current draw readings with two meters.

5low: Meter1=0.03A Meter2=0.04A

5high: Meter1=0.2A Meter2=0.21A

spot low: Meter1= 0.16A Meter2=0.17A

spot high: Meter1=0.72A Meter2=0.73A

Thanks eebowler!
Looks good for plenty of runtime on 5lo ='30-40ma'
The meter problem you encountered is not unique.
Kind of the opposite though,
With a Rayovac 3watt 2AA handheld: a runtime
test to shutoff- (no light out) , then removed the endcap and measured
current and the light came back on! -dimmer but on!
Quickly removed the meter and tried the paperclip turn-on trick and nothing!
Put the meter back on and got dim light!

Anyway good values for the Apex. You got improved runtime now which
is always a plus.
Any comment on why PT lists the runtime spec of hi(spot) as
Burn times (hours): Maxbright High (72); ???
Your measurement indicate the batteries would drain in 3 hours or
so to regulation cutoff. ??

Sway's runtime charts for the Apex (Just realized that this thread was created in 2005! )

The silly 72 hrs PT mentions is total runtime which includes regulated runtime AND unregulated runtime.