Vamo Pcb for a pass-through

[BryanM]

I just ordered a Vamo pcb to play around with before going with a Nivel or dna20.

I wondered what the max input voltage would be? In the stock Vamo, you can stack 18350s to get up to 8.2V... But I've got several laptop DC supplies that are up around 16V.. Is this safe to use as an input source to the Vamo?

I'm really not quite a mod noob.. Ive made 4 mods using an lm2596 (buck) pcb. I just dont know what kind of regulator is used with the Vamo (boost, i gather).

 

[dr g]

There has to be a buck feature if it can take stacked batteries. However I wouldn't expect 16v to be within the operating range of the device, that's pretty high voltage compared to what it is designed to see (8.4vish max)

 

[BigBaby]

I remember reading that someone was playing around with stacking batteries and that a Vamo will work fine with two stacked 18650's but would not work with three or more. If the 12-13v of 3 stacked 18650's was too much, 16v will be for sure.

 

[BryanM]

Good info... Thanks.

To use the laptop supply, maybe I'll try to buck down before the Vamo pcb. Not sure how this will effect the boost circuit...

 

[Relayer1974]

I learned an interesting bit about the vamo yesterday while testing with NiMH cells. Because it has two, count 'em, two "LO V" thresholds (for one cell and two lithium cells), there's a whole area below 6.4V and above ~4.5 volts where it just won't fire. I'm guessing it's a software feature, but I wish someone had a way to disable the "LO V" cutout at 6.4V.

 

[BryanM]

Hmmm... so how does the controller chip determine how many cells you're using? Measure the internal resistance?

I was thinking... if it didn't "know"... then there's some sort of current limitation in the NiMH cells that is below the required current (that's normally available in the high drain Li-Ion cells) for the Vamo boost circuit to operate.

This is interesting information to know, if I'm to attempt using an lm2596 to step down the voltage from a laptop DC power supply. It has a current output max of 2-3A.

 

[BryanM]

Maybe it's just determining this from the input voltage...

 

[Relayer1974]

Maybe it's just determining this from the input voltage...

That's what its behavior would indicate.

... then there's some sort of current limitation in the NiMH cells that is below the required current (that's normally available in the high drain Li-Ion cells) for the Vamo boost circuit to operate.

NiMH batteries are quite capable at 2C, which is well beyond what the Vamo board is capable of pulling.

 

[Relayer1974]

Now that I think about it, I've seen the cool kids in the flashlight and RC forums running NiMH cells at 10C. You can beat them like they owe you money and they'll take it like champs.

 

[Relayer1974]

BryanM, did you do anything with that Vamo board yet?

I did some bench testing and the Vamo definitely determines the number of cells by input voltage. It does this at startup (the three screen backlight flashes) and stays in that mode until the battery (or other power source) is disconnected. I fooled it into thinking one lithium cell was connected by putting a 100 ohm resistor in series to drop voltage when the backlight LED flashes. Then I used a switched jumper to effectively cut the resistor out of the circuit. It worked for my 4xAA NiMH battery pack, so it should work with USB voltage as well. I should be putting a mod together with the Vamo board when all my parts come in.

 

[BryanM]

BryanM, did you do anything with that Vamo board yet?

I've worked the Vamo into an Altoids Box mod... and have been enjoying it for the past week, while determining it's quirks. I plan to do some tests this weekend with a buck step down regulator and external power supply. I'll post here the results.

 

[BryanM]

I've verified that I can use a buck step-down regulator before the Vamo for use with a Laptop DC Power Supply... yippie.

I've also verified that voltage range you were talking about when it's powered up... If powered up between 4.5V and 6.3V, the Vamo will read LoV when hitting the fire button.

Wasn't sure if I should try to push higher in voltage to the Vamo... my DC supply goes up to 14V (one at work up to 16V). This buck should do nicely.

 

[Relayer1974]

I have tested it as high as 9V on the bench without issue. One thing I noticed is the peak voltage of the waveform rises as the supply voltage rises above 6V.

 

[Innocuous]

There are pics out there of some guy/vendor/table whatever where they added extensions and 18650 until it was like 12' long.

 

[BryanM]

There are pics out there of some guy/vendor/table whatever where they added extensions and 18650 until it was like 12' long.

uhh.. Was it still functional? Was it full of 18650s or just metal inserts for connectivity?

 

[Innocuous]

Oh, it was full of 18650's. I have no idea what the final count was.. I'd have to guess at like maybe 12 18650's? 15? It looked as long as the vendor-table, (yee old folding picnic/church table?)

 

[BryanM]

Oh, it was full of 18650's. I have no idea what the final count was.. I'd have to guess at like maybe 12 18650's? 15? It looked as long as the vendor-table, (yee old folding picnic/church table?)

12 18650s fully charged is about 48V... Well then.. I should take a closer look at the regulators on the PCB.

 

[BryanM]

Found This post, in this thread...

Maybe 16V will be fine..

 

[dr g]

Found This post, in this thread...

Maybe 16V will be fine..

I see no evidence or claims of functionality ... be careful

 

[WarHawk-AVG]

There are pics out there of some guy/vendor/table whatever where they added extensions and 18650 until it was like 12' long.

uhh.. Was it still functional? Was it full of 18650s or just metal inserts for connectivity?

Vamo Spear of Destiny
http://www.e-cigarette-forum.com/fo...-worlds-largest-mod-e-cig-4.html#post10719977
I don't think it was functional

I will say this a wired batteryless APV would be freeking sweet...I wonder if in order to handle current spikes if the ultra capacitors could be used as high farad capacitor banks to buffer between the source and the PCB when you fire it

Awesome idea...most interesting!

How about a 9vdc 5A AC/DC converter?
AC Converter Adapter DC 9V 5A 45W Power Supply Charger DC 5 5mm US EU UK AU Plug | eBay

Or a small form factor 12vdc ->9vdc 3A
DC DC 15W Converter 12V Step Down to 9V 3A Power Supply Module Auto Recovery | eBay
Input range: 8~23v

Might be somewhere to start..subscribing