Elly v Elly CREE v Elly Seoul v L1P RT's

[abvidledUK]

Very easy mod to do, replacing standard Elly led with Cree / Seoul star, both as supplied by Dealextreme.

Only thing to watch out for, negative wire also needs to wrap around holding screw, or be soldered to underside of Cree / Seoul Star.

The mod produces brighter light, and also a tighter spot, with no height modification at all with CREE Star.

With the Seoul, I had to unscrew the Elly reflector head approx 1.25 turns to get best spot & focus, as the Seoul sits higher when mounted in the Elly.

The head is thus very loose, and was held with tape for testing.

With the head tightened up against the body, Seoul was floody.

The original led mount is not thermal mounted to housing, I thermal pasted Cree / Seoul Star to housing, after confirming working ok.

Used 2,000 mah nimh AA's for rt's.

Initial measurements...

Original Elly LED:
Current to LED 130ma, current from battery 650ma

Cree'd Elly:
Current to LED 250ma, current from battery 1,100ma

SSC Seoul'd Elly:
Current to LED 230ma, current from battery 920ma

This pretty much is what you'd expect, approx twice the current, for twice (or more) the output.

Output approx two stops brighter for most of the 120 mins RT with Cree.

Similar for 180 mins of Seoul.

So CREE, higher curent, higher output, lower RT than Seoul.

A very welcome mod.

Two interesting details.

The CREE runs brighter, for similar duration as original Elly.

The Seoul runs brighter, for longer than original Elly.

The Cree'd Elly gets slightly warmer, but not so you'd really notice. Lukewarm.

Seoul, not really warm at all.

I also encountered the low voltage "problem" when turning torch on again.

When at low output, after 2/3 hours, the torch would not switch on again, with the depleted battery, at around 0.9v.

No problem really, down to electronics I suspect, battery exhausted anyway.


As usual, lightmeter reading are EV's (Exposure Values) with a reading of 8 being what I consider minimum useful illumination level

Horizontal X axis in 30 minute grads.

 

[glire]

Re: Elly v Elly CREE v L1P RT's

Thanks for posting this.

But I don't understand where is the Cree benefit here. Shouldn't the mod just give more brightness without sacrifying runtime ?

 

[abvidledUK]

Re: Elly v Elly CREE v L1P RT's

Thanks for posting this.

But I don't understand where is the Vree benefit here. Shouldn't the mod just give more brightness without sacrifying runtime ?

I think you get double benefit...

Lot more than twice the output, logarithmically.

2 EV is much greater than twice, for twice the current.

(4x)

And I don't think it can be direct comparison, because there's an electric circuit involved, which at greater current, may affect figure as per a simple direct drive comparison.

Perhaps others can go into more technical detail.

 

[aljsk8]

Re: Elly v Elly CREE v L1P RT's

ill be trying this with a seoul when it arives

thanks for the info

Alex

 

[protein_man]

Re: Elly v Elly CREE v L1P RT's

I just recieved my stock elly in the mail for dealextreme, with a fresh alk battery mine only pulls 450mA from the AA cell. The beam is very very blue but at least I'll have good runtime, about 5 hours or so on a nimh.

Going to put a cree in the sucka when they arrive!

 

[abvidledUK]

Re: Elly v Elly CREE v L1P RT's

I just recieved my stock elly in the mail for dealextreme, with a fresh alk battery mine only pulls 450mA from the AA cell. The beam is very very blue but at least I'll have good runtime, about 5 hours or so on a nimh.

Going to put a cree in the sucka when they arrive!

As usual, alkalines have higher internal resistance, so in general, for most torches, the current draw (and illumination ) is less than with nimh's, all other things being equal.

Note, on my RT graph, the grads are 30 mins, so RT only 2.5 hours. (5 grads)

I have several Elly's, some are slightly blue, some whitish.

I mod the blueish ones.

Now, what to do with the old emitters ?

I have a few Xenons on standby, along with some CR123 spacers.

 

[Aepoc]

Re: Elly v Elly CREE v L1P RT's

Are you going to use a star or any other board for the Soeul? If so what are you going to use and where are you getting it from? I have only found one emitter star combo for sale at dealextreme and they are sold out. This doesn't bother me too much since i heard that they were just mounted on cheapo luxeon stars. Are there any boards specifically designed for the Souel P4?

 

[abvidledUK]

Re: Elly v Elly CREE v L1P RT's

DX Star for Seoul.

 

[abvidledUK]

Re: Elly v Elly CREE v L1P RT's

Updated: First Post in this thread.

I have added the RT's for the Seoul Star, as well as the CREE Star, to the Elly RT's.

All items supplied by Dealextreme.

 

[kanarie]

humm the Seoul seems to outperform the Cree quite a bit

 

[abvidledUK]

humm the Seoul seems to outperform the Cree quite a bit

I didn't like the need to undo the reflector though to get best beam.

I think it only outperforms it in that it takes less current through the electronics, giving longer RT.

The actual light level / output I measured is a little less.

 

[Led_Blind]

I prefer the seul output as well. As for the wobbly threads, just add a fatter o-ring. If thats not enough, wrap plumbers tape round the threads to prefrence

 

[Aepoc]

I recently got a USWOH Seoul and it is deffinately way brighter then the XR-E mod that I completed earlier. I am waiting on some wizard 2's and then the real comparison will be visible.

 

[abvidledUK]

I noticed tonight that my Seoul SSC P4'd Elly didn't switch on for a few seconds using Alkaline AA, after having been on for a short while.

I measured the AA volts, it was 1.15v, off Elly load.

Switching on, after a few seconds rest, the Elly then continued to stay lit, and bright for another hour.

Of course, after this hour, it would not switch on at all, AA volts 1.08v.

It was still bright, would probably have stayed lit for a good while longer, if not switched off.

So, quite a good AA sucker then.

It was a part used Alkaline, so no idea what total RT was, amazing.

 

[MorePower]

Running my Cree-modded Elly off a power supply, the lowest Vin I could use to get it to turn on was 1.12V. I think there's probably more than a bit of variation in the startup voltage for the boost circuit, but it looks to be fairly high. Not a problem usually for alkalines, even when fairly deeply discharged.

 

[mzzj]

Running my Cree-modded Elly off a power supply, the lowest Vin I could use to get it to turn on was 1.12V. I think there's probably more than a bit of variation in the startup voltage for the boost circuit, but it looks to be fairly high. Not a problem usually for alkalines, even when fairly deeply discharged.

Yeah, turn-on voltage varies from unit to unit because Elly uses mosfet as a switch and mosfet gate treshold voltage is always bit "random". I have one that starts at 0.9v and another starting at 1.1v.

There is a trick to modify Elly driverboard to start reliably every time with less than 0.8v input, all you need is NPN-transistor and one 1k resistor...

 

[Bertrik]

mzzj, can you please explain the trick with the NPN-transistor and the 1k resistor?

 

[joedm]

There is a trick to modify Elly driverboard to start reliably every time with less than 0.8v input, all you need is NPN-transistor and one 1k resistor...

C'mon tell us!!!!

 

[mzzj]

C'mon tell us!!!!

Connect NPN transistor parallei to Q1. It's very difficult if not impossible to manufacture mosfets with gate treshold voltages below 1v, but ordinary NPN transistor works already with 0.7v!

Emitter goes to Q1 upper pin. (Hold driverboard with inductor upwards.)
Collector goes to Q1 middle pin.
Base connected with 1k resistor in series to Q1 lowest pin

I used BC337-40 transistor but any fairly similar transistor should work. Something "around" 10-100v, 50ma-1A and HFE more than 100.

 

[joedm]

thanks mzzj,

If I manage to resurrect my current Elly I'll give it a go.