Kai's driver 5025

[Mitica]

I have this driver from Kai (http://www.kaidomain.com/ProductDetails.aspx?ProductId=1845) SKU: S005025, and from what I've read here is quit uncertain what this can perform. I have to say that I'm using it with a 3xD body and a P7
From my measurements, with 3xD regular batteries I get only 0.9 A on tailcap. With 3 rechargables AA the results are the same. If the voltage drops so is the A, for example now I have only 4V on 3xD cells and the draw is only 0.5 A on high. However if I directly connect the cells to LED I'm able to squeze 1.6 A from 3 rechargeable AA.
From this thread I understand that nailbender is able to get 3 A on tailcap
I'm a litle bit confused about my results..
If this driver is a Direct drive (which I guess it is good for efficiency) why I'm not able to get 1.6 A, as much as I get for connecting the led directly to batteries? Should I assume that I have some high resistance component on path? The only thin wires that I have are the one from driver to led, those are from an ethernet cable, but they are short (5 cm?) and made from cooper.
Do you think that better batteries will bring more power or this is limited by the driver? I would be happy if I could send 1.5 A to led, since I'm using the flash in campings, where I could carry to many rechargables
Thanks

 

[Linger]

:welcome: I'm sorry your torch doesn't work. It does sound like you made some good choices at the beginning.

What kind of 'D' batteries are you using? Nimh? Nicd? Alkaline batteries only have so much power and expecting 1.5A from them won't work too well for too long.
I really like that driver, but mainly for 18650 (lithium) cells. As that driver cannot boost voltage, as your alkaline cells are depleted you'll loose output. I understand you want 1.5A, but if you continue to have problems, consider a buck / boost driver from KD / DX
http://www.dealextreme.com/details.dx/sku.15880
This driver is excellent for 1.0 - 1.2A and it will hold that out-put level down to ~.9v from the cell. I know that 1A output is not very much for a P7, but if you can't get the original set-up to work, 1.2A is a lot better than the 500ma you are currently getting!
http://www.candlepowerforums.com/vb/showthread.php?t=258679
------------------------

Are you sure it is in 'high' mode? 600ma sounds about 'medium' drive level: have you checked readings for other modes to confirm?

If it is in 'high,' this could be the emitter, the driver, the wiring, or the power source.

Do you have a lithium cell to test it? If you can get a decent reading (1.8A from an AW 18650) then you'll have isolated issue with power supply.

Good idea trying with 3x AA batteries. What happens with 4x 'D' or 4x AA batteries? (driver should be OK up to 6v even though it says 4.5v, just don't exceed that. I have fried one accidentally connecting two rcr123's in series instead of in parrallel to it )

I've used many copies of that same driver. While many people will say that quality control is not guarenteed from KD, all of my drivers have performed about the same.

A pic of your wiring may be helpful. I'm don't like the sound of the internet cable part, but you have made some good choices so maybe that one was a good choice as well.

Welcome! :wave:You'll get this one going soon I'm sure.

 

[old4570]

Which P7 ... J-bin or I-bin

A J-bin will draw less current with this driver ...
Also very dependent on battery ..

Yes check with a 18650 !!!! If its a J-bin expect 1.8 to 2A
If its a I-bin expect more than 2A current draw . [ 18650 ]

Fully charged nicads might give you close to 4v total ..

I have used Dry cells in my SSC P7 and output is down to just over 300Lumen and current around 0.6A .... with a fair bit of voltage sag ... [ 9 x AA ]

 

[Mitica]

First of all, thank you for your responses. My P7 is a CSXOI, and until now I had used Zinc Carbon D size batteries until now for test.
Unfortunately I don't have a 18650 . My idea was to build a flash that will benefit from the superior randament of leds but to use regular batteries that are common and you cand find anywhere. Meanwhile seems that i was infected by flashcoholic virus
Evening news: I've tested the setup with 4 AA rechargeable, 5.2 V. The draw was 1.6 A.:naughty:
But with 3 AA, 3,88 V, the draw on high is only 0.6 A (the same chargeables)
So I guess I did not chose the right driver, I have to buy a buck/bust driver like Linger suggested
@old457.. you are usind the 12 AA in s or p?

 

[Techjunkie]

That driver isn't really a "driver" in the true meaning of the name. It is a PWM dimmer only. Even when it is on high mode, it adds some resistance to the circuit, so it will never be as bright as your torch without it in straight direct drive.

 

[Mitica]

Sorry but I don't understand... 1.6 A draw, DD with 3 AA. The draw from the same 3 AA with driver is just 0,6 A. Isn't it quite a big diference for PWM dimming??

 

[old4570]

Remember its a voltage thing as well ... The driver/controller was designed for 4.2v use , so will put out until the voltage drops bellow a certain point , usually the voltage ratting of the emitter or driver .

Also the driver/controller is direct drive to a point ......

It will allow up to 2.8A current flow , and limit voltage to [ forget now ] a certain point as long as the batteries are above that point .. Once the batteries fall bellow that point output will drop . [ could be 3.7v ]

This is not a boost driver , nor a buck driver ..
KD has a boost/buck driver for 2.5A if I remember , but its only single mode .

With SSC P7 its important to chose batteries and driver combination carefully , so as to keep the SSC P7 emitter powered up .

Mine is 9xAA or 3D mag with 3 x AA carriers , I chose this combination to keep the voltage higher than the Vf of the emitter , for good regulated output .

3 x D cell will = 4.5v ...
But the batteries may suffer some voltage sag and running dry or alkaline will limit the Watts available [ Voltage x Amps ]

To get a really good 3 x D light , you may want to try XP-G R4/5 emitter rather than a SSC P7 , if you want to run dry/alkaline .

That driver would work well with 18650 ... [ which it was designed for ]
+ The voltage sag will not help ...

You have a multimeter , so when you measure current draw , set it to measure voltage , and see how much sag there is under load [ measure the same way as amps ] .. measure for 30 seconds or more to see how much they sag ...

+ Dont worry to much , its all about learning stuff , and having a bit of fun , the fun part is important !

If you bye pass the driver/controller , then your working with the vF of the emitter [ voltage rating ] Lets say its 3.4v for arguments sake ...
As long as your batteries are above that voltage , you should see good output , + dependent on how much current can be delivered .
So going without a driver/controller is not the end of the world when using dry cells or nicads .. Could be a problem with Li-ion .. [ but your not using them ]

Its a lot to take in I guess , and I hope I haven't confused you .