Nameless - my ugly VV

[shortyjacobs]

So I quickly tired of my first mod, the Dupblow. It was a great first try, but has some issues. For one, I'm worried about snapping off the carto /atty when I shove it in my pocket. Also, it's heavy, I can't control the voltage, and it's heavy....pretty damn heavy.

So here's nameless. I still have no idea how to make a case for it. Duplo blocks won't fit over it. Any square tubing is big and klunky. I'm thinking I'll have to fashion a metal sheath for it, but don't know how to secure it on there...

Anyway, until it gets a case, it still works. It's two 14500 lithium ions in series, with a TI PTR08100 stepping regulator chip and thumbwheel pot for adjusting voltage, (based on the Evercool circuit). The carto/atty is recessed halfway into the body, so it's nice and stable. Pushbutton fire, slide switch safety. It's ugly, but it fires! (And it was my first time soldering on a PCB, boy is that tiny).

(all pics click for bigger, oh and that's a "mega" carto in there...a "standard" carto only sticks out about 1.5 cm, and an atty sticks out only about 8 mm)



Comparison to Dupblow:

 

[Hottody]

Trash that ugly duckling! Time to invest in something new! Life is to short, hell...when you get maried your stuck with that baggage for the rest of your life! This is just one ugly underperforming mod that does not deseve a spot in your pocket or your mouth!

joking, as I've been married for 22 years...but really this thing should be put to rest!

 

[Quigsworth]

This is just one ugly underperforming mod that does not deseve a spot in your pocket or your mouth!

Woh!, that's hard tody, lol, he'd better smooth out that plumbers putty though, Shorty's finger prints are now on file with HLS...

 

[Dandafixr]

look promising, the only worry i see is being able to clean the batt connection if you overfill your carto

 

[shortyjacobs]

Yeah, I'm an engineer, so I go for function over form . I'm just super happy it all fit in, (it was a tight squeeze), and happy with my PCB soldering skills, (I should have taken a pic before I epoxied it in, but I was too excited). It fits really nicely in my pocket, and the putty is actually much smoother than the pics make it look. Makes perfect finger rests until I fab up a case for it. I'm waffling between wood, (easier to work with), and flattened altoid tins, (thinner)...My biggest problem is that I need to get into it to change batts...

Tested the voltage range today. 3.4V up to 6.5V unloaded, and the chip can handle up to 10A so it runs nice and cool.

ETA: dandafixer - yeah, I had that concern too, especially after I put a case around it, if the case doesn't have that side easily accesible. A Q-tip fits down from the top nicely though, so as long as I don't flood the thing out with mLs of extra juice, I should be good.

 

[asdaq]

You could see how a tennis racket handle grip would fit on it, think of it like a thick silicone condom. With the switch located low like you have, a hole for the carto in the end of it and a slot for teh switch would probably work best. Available at a sporting goods store, walmart and big-5 is what I hear.

 

[shortyjacobs]

You could see how a tennis racket handle grip would fit on it, think of it like a thick silicone condom. With the switch located low like you have, a hole for the carto in the end of it and a slot for teh switch would probably work best. Available at a sporting goods store, walmart and big-5 is what I hear.

Brilliant asdaq, I'll look into it!

Sent from my phone...excuse the spelling mistakrs.

 

[alekos557]

3aa box should be able to fit all the guts.

 

[WillyB]

Tested the voltage range today. 3.4V up to 6.5V unloaded, and the chip can handle up to 10A so it runs nice and cool.

Better review the datasheet. That TI assembly has a 5.5V max rating.

The minimum resistance between VOAdjust and GND is limited to 240 Ω.

You'll note that the voltage chart tops out at 5.5V.

 

[shortyjacobs]

Better review the datasheet. That TI assembly has a 5.5V max rating.



You'll note that the voltage chart tops out at 5.5V.

lol, oops. I guess that's the effect of me using a 200 ohm resistor in series with my 200 ohm pot. I probably should have read the datasheet and gone with a 240 ohm resistor, (explains why the Evercool uses a 220 ohm...but still, why not 240? answer's probably buried in hsi thread).

Welp, I'll have to mark the pot at "max volts" so I don't go over and fry the chip. Thanks for the tip!

 

[WillyB]

Actually it's always a good idea to meter your resistors and trimmers. A 220 could be anywhere from 210 - 230Ω (at least with the ones I use).

Many name brand trimmers can have tolerances of 10% and up.

Here's one that I'm sure many have used.

91AR200KLF BI Technologies Trimmer Resistors - Through Hole

Tolerance: 20 %

Does that make it bad? Not necessarily as long as you meter it and see how it's actual ohms will work in your application. Many times, lower is a good thing. Do you really need it to go down to 3.4V?

It's nice to see you stepping up and a adjusting your mods accordingly as things (from actual use) start to fall in place.