guide for a VV booster? or anyone know of a PCB supplier.

[Lance_Wallen]

I'm looking for the smallest package I can put together that will buck/boost a 3.7v battery from 3.0ish to 6ish. A little shy of 6 or a little over 3 is fine but I want that range. I've hunted for PCBs 'preman' but can't find anything. if there's a circuit guide that'd be great or if anyone knows of a pre made board that'd be even better

 

[lynch]

Did you try ebay ?

 

[ChaosAffect]

Only one I know of is the TI Boost Board. Hope there's something smaller, though. That one's kinda a beast.

 

[Dalton63841]

The TI ptn04050C is pretty much the only booster currently usable for our application, at least without going significantly larger. Even at that, the ptn04050C has to be "tricked" into going down to about 3.8v, as it is not meant to go below 5v.

 

[Lance_Wallen]

how does the provari and buzz pro type mods pull it off?

 

[Dalton63841]

The Buzz Pro regulates DOWN, using a 2 battery setup. It's easier to get a better range that way, but you have to have 2 batteries. The Provari uses a proprietary PWM circuit with parts that are not feasible for use by a modder(read: ridiculously TINY surface mount chips).

 

[Lance_Wallen]

hrm, guess I was hoping there was a place I could order a circuit from with the right components. I'm good with a soldering iron but not microcircuity good

 

[bradkb]

The TI board is great and pretty small, how small do you need it to be?

 

[WillyB]

The TI ptn04050C is pretty much the only booster currently usable for our application, at least without going significantly larger. Even at that, the ptn04050C has to be "tricked" into going down to about 3.8v, as it is not meant to go below 5v.

Actually the buck boosters are always meant to produce an output higher than the input.

There are some more sophisticated circuits that do both, boost and step down.

The main problem with the TI booster is it's rather low, by today's standards, amp/watts capability.

When Nuck, an early user of the TI's, built his Fistpacks it was designed around the DSE901 atty.

 

[mv2envy]

TI does make a buck booster that goes from 1.2V to 5.5V and has a 3 Amp limit but its a 14pin setup and is meant to be surface mounted. Digikey has them if you feel like messing with one to test out. Part number is TPS63020DSJR

 

[Dalton63841]

TI does make a buck booster that goes from 1.2V to 5.5V and has a 3 Amp limit but its a 14pin setup and is meant to be surface mounted. Digikey has them if you feel like messing with one to test out. Part number is TPS63020DSJR

LOL It should be pointed out that while this chip WOULD work, it is surface mount, has 14 pins and is only 3.3mm x 4.3mm in size.

 

[mv2envy]

It was pointed out! Read my post!

 

[Dalton63841]

It was pointed out! Read my post!

LOL Actually I was referring to the size. 14 pin surface mount would be painfully tiny on a 3x4mm chip.

 

[executivul]

Not to mention the external feedback network which must be designed with strict specs otherwise the controller gets unstable and voltage varies very much (you set it to 4.7 and you get from 4.2 to 5.3 fluctuating!)
The simplest way is either use a 4050c with it's 12W limit (usable on most atties) or get a step down like the ptr08100, put 2 batteries in series and with it's performance of over 90% you get from 2x14500 the same you would get from a large 18650.
Just remeber energy does not come from nowhere and does not vanish, what you draw from battery gets transformed into heat, 90% atty and the rest in the converter stage losses. So higher input voltage means less mah drawn from the battery, less stress on the batteries, longer life.


Sent from my iPad using Tapatalk.

 

[mv2envy]

Its hard to believe that there isnt a better buck/boost regulator out there that better fits our needs than the 4050C. 2.5A is just not enough to drive a DC carto to 5.2V. Thats why Ill stick to my dual batt OKR-T/6 setup.

 

[CraigHB]

Yea, it is hard to believe there isn't something out there. I guess higher power POL boost regulators are not something in high demand, they're mostly buck. I haven't noticed any buck-boost POL modules out there, let alone one powerful enough for an e-cig mod.

I'm not positive one way or the other myself, but someone said the Pro-Vari uses an LTC3785 which is a really trick buck-boost controller. Like most DC-DC converter controllers, it requires some engineering to derive component values and uses a chip package that is quite difficult to solder by hand. Definitely not something for the casual hobbyist. I've been tempted to try a mod myself with that controller, but I've decided I really have no need to buck a single cell. That controller is more complicated and harder to stabilize as well. I'm sticking with the TPS43000 in a synchronous boost configuration.

 

[mv2envy]

Yea, it is hard to believe there isn't something out there. I guess higher power POL boost regulators are not something in high demand, they're mostly buck. I haven't noticed any buck-boost POL modules out there, let alone one powerful enough for an e-cig mod.

I'm not positive one way or the other myself, but someone said the Pro-Vari uses an LTC3785 which is a really trick buck-boost controller. Like most DC-DC converter controllers, it requires some engineering to derive component values and uses a chip package that is quite difficult to solder by hand. Definitely not something for the casual hobbyist. I've been tempted to try a mod myself with that controller, but I've decided I really have no need to buck a single cell. That controller is more complicated and harder to stabilize as well. I'm sticking with the TPS43000 in a synchronous boost configuration.

that chip looks very interesting! Have you built a mod using it yet?

 

[CraigHB]

Not with the LTC3785, but I've build several mods mods with the TPS43000. It's a really nice full featured controller. I tried doing a SEPIC with it, but couldn't get the efficiency up high enough to make it worthwhile. Major fail there. So, I've been just been building boost converters with it, much higher output than the TI POL boost regulator, can drive anything up to 6V, great efficiency. Requires a high drain batt though, been using a LiPo cell.

Working on a new mod with the TPS43000 controller now. I'm trying to shrink things down a lot for this one, will use a smaller cell. Going to try using a couple MLCC output caps for the converter instead of the bulky tantalum polymers I've been using. Makes it a lot smaller, but harder to stabilize. Don't know how well that's going to work yet, haven't got that far into it, still designing everything else, some new features to work out, testing subcircuits right now. The converter has specific layout requirements (DC-DC converters are sensitive to that kind of thing) so I can't test it until I have a finished PCB. I can't just slap it on one of my sucky home brew jobs to test it, have to have a full ground plane. Need a manufactured board.

 

[ScroungerLee]

CraigHB how on earth do you solder the TPS43000? .65mm centers on the pins, wow!

Lee

 

[mv2envy]

Almost sounds like more trouble than its worth! 2S mods are so much easier, lol.