Multi-level driver for SSC P7 under $8 ?

[TorchBoy]

when Vbat < Vf + 0.6V the driver is out regulation and switches in direct drive mode ; but with a 0.6V drop out added ...

For normal Vf LEDs the out-of-regulation condition is Vbat < Vf + 0.12V. For low Vf LEDs there's an extra condition if the AMC7135 Vdd pin is fed through a diode, which is Vf < 3.3V, or the 2.7V needed by the AMC7135 to stay in regulation plus the 0.6V for the diode. The P7 doesn't meet that condition.

(And remember that the Vf is question is the Vf needed at the current for all the AMC7135s being used at that particular moment, not the LED's Vf at 330-350 mA for a single AMC7135.)

Are you thinking of switching in an extra AMC7135 when they fall out of regulation or having it there the whole time?

 

[freedom2000]

Are you thinking of switching in an extra AMC7135 when they fall out of regulation or having it there the whole time?

Correct me if I am wrong, but switching in an extra AMC when they fall out of regulation will not solve any problem... you will still be in "direct drive" mode... no more juice from the battery !

BTW I did a mistake the drop out of the AMC7135 is 0.12V and not 0.6V as stated in my previous message...

JP

 

[TorchBoy]

no more juice from the battery !

It should give slightly more juice, but after they all drop out of regulation it would be like trying to sweep water uphill. You'd be using a slightly bigger broom but you'd still be fighting a losing battle.

 

[X_Marine]

just out of curiousity, do any of you guys know what your doing?

i'm taking electrical engineering, and thought i might built a high ampere voltage booster from scratch for the p7 to a) test what i've learned b) make a single wafer voltage booster for p7 and beyond and c) have somthing to show come graduation.

anyways, i've been reading over what eveyone is saying it sounds like most of you are useing a trial and error approch.

so back to my previous question. do any of you have any knowlege of what your doing? either self taught or institutional, or are learning from trial and error?

i'm not trying to be rude, just inquisitive.

I think that would be a great idea and of course you can always run it by your instructor for opinions and possible improvements.
Why not put a schematic together and let us see what you come up with. There are some pretty good circuits already on the forums if you do some searching.

Best with your class
X/BillyD..

 

[rizky_p]

is it possible to build 3 seperate boost driver in 1 board? and run them in paralel to achieve 3A output?

 

[TorchBoy]

is it possible to build 3 seperate boost driver in 1 board? and run them in paralel to achieve 3A output?

I don't see why not. Your board might end up three times the normal size though.

 

[rizky_p]

I don't see why not. Your board might end up three times the normal size though.

any problem when combining boost driver output?

 

[darkzero]

is it possible to build 3 seperate boost driver in 1 board? and run them in paralel to achieve 3A output?

Yes possible. Except for having it all on one PCB that's pretty much what I did here. That was expensive!

 

[rizky_p]

Yes possible. Except for having it all on one PCB that's pretty much what I did here. That was expensive!

that is one expensive solution

Is it possible to run GD3000 with 2xD NiMh cells?

thanks.

 

[Changchung]

Hi there, I am a little confused, in the first pic you show, the controller and the driver, but in the second one you show to drivers with 8 AMC7135 total, if I add this 8 to the 3 AMC7135 wich is in the driver we have 11 AMC7135 total, I am correct??? Or I need just 7 AMC7135? 4 wich is in circuit board and 3 in the controller or driver???

I have everything now to make the mod, I just want to be sure before I started...

 

[kanarie]

If I want to use two of these multi mode drivers were do I bypass the mode IC on the second board

 

[StefanFS]

If I want to use two of these multi mode drivers were do I bypass the mode IC on the second board

Like this, you really need to remove the IC for it to work:
https://www.candlepowerforums.com/posts/2612230&postcount=94

 

[Kihlstrand]

Nice thread everyone. I will use these drivers in my MAG P7 mod.

Regards
Johan Kihlstrand

 

[Kihlstrand]

By the way. How much voltage do you feed these PCB:s with? Is a single lithium 3.7v battery enough? or will it need more juice to produce 2.4mA?

Regards
Johan

 

[javiole]

cheap and it works great!!! cheers

 

[bbgobie]

When using this method, how do the modes work?
Is it 100%/35%.... etc of the total AMC7135 output?
Or is it 100%/35%.... etc of the output of the controller board + 100% of the 2nd board?

Also any reason this wouldn't work with Downloads multi led 7135 setup?
https://www.candlepowerforums.com/threads/201392

I'm thinking MCE 2S2P setup, 1400mA output and 2x 18650s for a simple efficient setup.

Thanks!

 

[VidPro]

By the way. How much voltage do you feed these PCB:s with? Is a single lithium 3.7v battery enough? or will it need more juice to produce 2.4mA?

Regards
Johan

the ones with that particular chip in them, current regulate by clipping and wasting the voltage that goes over what is needed to make it to the current (to drive the led) .
so say your LED Voltage (Vf) is at 3.7 (at the current) and your battery is at 4.0v these things will just burn up the extra power (so to speak) and keep the voltage right for the ammount of current.

so say your battery is at 3.5V , your led will be at or below that (due to the slight resistance of the curcuit) which means it will fall out of regulation, and Basically be Direct drive.

so its all about the voltage of your battery and the voltage your led runs at (when at that current).
when the battery is Above the LED voltage , it will clip it off to maintain the current , if its below that voltage it will do NOTHING but sit there basically

So in short, it is Resistance when the battery voltage is too high.

on MOST white led stuff this will mean when your battery is fully charged the LED will be at its full current, and as soon as the battery goes below about 3.6-3.9 the output will start to dwindle.

its a good "answer" to direct driving, without breaking something, but it will NOT boost the voltage when the battery goes to low.

so its all about the VOLTAGE of your LED at that amperage, and the battery voltage at that load.

because the 1xli-ion or 3xNimhy or 3xalkaline or 3x1.7v lithium is very CLOSE to the voltage of the leds were using, it clips great for those items.

and it will still clip well for 4x1.5v too, wasting a bit more, but staying in "regulation" longer.

but NOT for batteries over ~5.5volts (under load), because then it has to waste to much juice resisting, and the part will heat up.

it was best said once by a member here, its a Glorified resister , it acts as needed ONLY when the voltage is TO HIGH for the LED (at that current level)

 

[JimZinVT]

Could this combo of driver boards be made to run at ~1400mA? Remove some IC chips from one board or the other? Thanks.

JZ

 

[NetKidz]

Could this combo of driver boards be made to run at ~1400mA? Remove some IC chips from one board or the other? Thanks.

JZ

Yes.

But there're already 4x7135 boards and will push about 1.2~1.4A.

PS. There's also 8x7135 in one 17mm board (double sided). I've asked DX to source it. Let's wait and see. :devil:

 

[kwarwick]

Yes.

But there're already 4x7135 boards and will push about 1.2~1.4A.

I've been looking for a 4 x AMC7135 board with modes like the 16 mode 3x AMC7135 boards, but haven't found any. Would you be so kind as to tell if that one has similar modes and where you found it?

Karl