Vaping with eCigarettes

[Miguel]

That schematic doesn't look right to me, either, for some reason I remember mosfets as having 4 contacts.

They do...but most common pinouts have them connected to the source internally, since that's the most common bias configuration.  It's called the 'B' terminal (for 'body', or 'bulk') and connects to the substrate of the channel.

What amounts of heater current and battery voltages are common in these configurations?  A 3.6V LiPo battery across a 4 ohm coil is about 1 Amp of current.

And yes, it'll get hot.  You are dissipating I*I*R Watts (about 0.03W or 30 mW) in that tiny package, which does not have a lot of surface area to dissipate the heat.  The only way to correct this is to heat-sink it (not practical in a tiny space), mount it to a PCB with a copper heat pad (more common), or add resistance to lower the current through the coil.  Although I would not worry about it too much:  even at 70C that FET is rated to dissipate 0.5W steady state, which is MUCH higher.

[MahrinSkel]

Without an SMT pick and place machine, you don't want to mess with anything that small without a socket.  Anything with less than a 2mm spacing between pins is a pure bitch to try and hand solder, even that's not easy.

--Dave

EDIT: And yes, the heat is normal, you need to plan for heat dissipation in anything routing that much current.  In a custom PCB, you'd put an electrically null layer of copper (not connected to any voltage or ground) under them, two layers with conduction between them.  Even the trivial waste heat can add up to a really hot chip if you don't do something with it.  That's why my design calls for a metal disk as the top cap, once I start doing more with that current than passing it through wires, heat buildup becomes a concern and I've got to get it outside the pipe body or I'm building an incendiary grenade.  A mosfet's leakage is comparatively minor, a socket with a built-in heat pad will take care of it, but once you start regulating voltage or current that 5-20% waste power comes out as pure heat from the IC's.

Miguel: Yes, if anything he's a little high on resistance (most eCig's are running 3.1-3.5 ohms, 510's run 2.8-3.0).  1000-1250 mA is the typical current for an eCig, that's why there's such a big gain from getting a bigger battery, it brings discharge under 2C.

[Nerf]

Actually this one is on a USB passthru, so 5.15v source, ammeter puts it at about 1.5A.
I ordered some SOT223 mosfets last night, they're about 6x4mm without leads and 6x7 with leads, so it should be much easier for me to solder but will still fit on the laser PCB.

Peak voltage on the 3.6v li-ions is 4.2v, you'll notice performance start to drop a bit when they hit 3.6v.  The passthru I made last night with the mosfet seems to be working great though, but I'm still trying to figure out how I'm getting a voltage drop of about .5v V @ 5.15v.  The Rds(on) is listed at .06ohm at 4.5v, but I think the chart I need to be paying attention to is the junction temperature resistance chart which puts it at 1ohm @ 50*C.

Not really sure on all that, but even with a slight voltage drop its worth it to get the current away from that switch.

[Miguel]

Ok, here what I came up with:

1) I moved the coil to the drain side of the transistor:  for N-channels referenced to ground, you want the source solidly at ground potential.  Remember that threshold voltage is referenced from the source (ground) reference, and if the load is on the source side this will 'lift' the source and want to 'turn-off' the transistor.  This increases the channel resistance and lowers the gain.  Remember that 1A through 4 ohms is a 4V drop, so you were basically using it as a diode.

2) Added 10k pull-down to gate:  when the switch is open, the gate cannot be floating, or else it can float to a level that partially turns on the transistor and makes it leak current through the load.  The pull-down gives the gate a ground reference when the switch is open, and is of high enough value not to cause a large battery drain when the switch is closed.

3) Added series resistance in the LED:  basically LED's look like wires to the circuit when they are forward biased, and you were effectively shorting the coil.  The only thing to limit the current through the LED is it's PN junction resistance and the resistance of the wires (almost nil).  The resistor current-limits the LED to 30mA, which should allow it to last a LOT longer.  It will also provide more current to the coil.

Here's a simulation and schematic:

Switch open:  notice that the pull-down turns the transistor solidly off:  the 4uA is junction leakage only.



Switch closed:  you see the drain voltage is 10mV (nearly ground), with 1A, so the channel resistance (under these ideal biasing conditions) is 10 mOhm, and power dissipation in Q1 is only 10mW.  You can see that the LED is now on (the graphic arrows turn blue).



Also:  ignore the 2SK2553L designation...it was the closest component I had in the Spice library to match the Vishay part number and I didn't want to go and find and import the real model.

If you want to get REALLY nitpicky, I would also add a small ceramic cap across the switch contacts to reduce arching.  Remember the switch will pull the gate from ground to the battery voltage in a VERY short time, so adding a cap across the switch contacts lessens the current initially going through the switch and will make the contacts last longer (although at ~4V it's probably not a big deal).

[Miguel]

Shit I thought that was a PM....

Oh well, hopefully someone else can make use of it too.

[Ookii]

If you perfect the ecigarette, then you have my blessing.

[Kitsune]

So, it begs the question: have the potheads worked out how to get liquid weed yet?  Any sort of weird contraption that you can inhale from is already in danger of getting you tased if you're pulled over for speeding.  A weird contraption that's known to be used by stoners is virtually guaranteed to elicit some police brutality, and could put a real fast damper on this little industry.

[gryeyes]

kidding?

[Furiously]

Since the FDA has determined Cloves are evil. Anyone have a good source for clove juice?

[Mrbloodworth]

kidding?

Sadly, no.

[Ookii]

Since the FDA has determined Cloves are evil. Anyone have a good source for clove juice?

Just go online and buy packs, cheaper than stores were anyway.

http://www.clovecigarettesstore.com/djarum-kretek-cigarettes/view-all-products.html

Straight from Indonesia!

[schild]

So, it begs the question: have the potheads worked out how to get liquid weed yet?  Any sort of weird contraption that you can inhale from is already in danger of getting you tased if you're pulled over for speeding.  A weird contraption that's known to be used by stoners is virtually guaranteed to elicit some police brutality, and could put a real fast damper on this little industry.

Potheads are botanists, not engineers.

[Sheepherder]

So, it begs the question: have the potheads worked out how to get liquid weed yet?

THC is lipid-soluble and hydrophobic.  Which is why hashbrownies work and Hash₂O doesn't, which makes it problematic for intravenous and inhaled usage, aside from smoking it.

Oddly, I don't smoke anything, I just find the entire premise of this thread amusing.  Also somewhat interesting, as it would be an excellent turn of events if E-cigs completely killed off the market for cigarettes.

[Kitsune]

kidding?

Yeah, not kidding.  Try smoking tobacco from a glass pipe or bong, then convincing your local law officials not to kick down your doors in search of a pot-growing farm.  If it looks weird, and you're inhaling from it, you can bet that nine cops out of ten will think you're on some serious drug.  At least with rolling paper you can show a pouch of tobacco to prove you're making cigarettes instead of joints, what cop is going to recognize a vial of colorless liquid as liquid nicotine?

[MahrinSkel]

kidding?

Yeah, not kidding.  Try smoking tobacco from a glass pipe or bong, then convincing your local law officials not to kick down your doors in search of a pot-growing farm.  If it looks weird, and you're inhaling from it, you can bet that nine cops out of ten will think you're on some serious drug.  At least with rolling paper you can show a pouch of tobacco to prove you're making cigarettes instead of joints, what cop is going to recognize a vial of colorless liquid as liquid nicotine?

Heheh, funny story.  So, I'm driving back from Dallas with a large Ziploc bag full of brown bottles, vials, odd looking bits of electronic detritus, and assorted other oddments sitting on the passenger seat.  I stop at the rest area just south of Dallas, and when I come out there's a man and woman looking in the window of my car.  The woman sees me, says something to the man, and they both very nonchalantly walk off.  I get in my car and drive away.

Within 5 miles, I have a police car in my rear-view mirror, and for the next 150 or so miles I have some form of police car riding my ass at least half of the time (just working from the ones where I was eventually able to see enough to be sure it was a cop, I may have been tailed the entire way).  I get to Temple (major speed trap), and finally one of them lights up and pulls me over.  For about 2 seconds I consider hiding the bag, then decide it's better to act as if I have no idea I might even want to hide it, and leave it in plain sight on the passenger seat.

Story is that a local police deputy saw someone answering my description in a car like mine driving on the frontage road with no seat belt (they can stop you for that in Texas).  He wants me to wait until that local cop shows up to confirm the ID (keep in mind, the state trooper that pulled me over had followed me since I hit the county line, and I know he knew I hadn't left the freeway since Dallas).  So I get to sit there on the side of the road, engine off, under about a million candlepower of lights, waiting for this fictional deputy for the better part of an hour starting at midnight.  Fortunately, it was the first cool night in central TX since May, and not too unpleasant (I had a book).

Finally, he comes back to my window for the third or fourth time, and gets around to asking the question he really wanted to ask all along: "So, what is that stuff in the bag, anyway?"  So I get to give him the spiel about eCig's, and nicotine solution, and the ePipe I'm considering making, and so on, 10 minutes or so of fascinating detail about the minutiae of low-voltage heating circuits, li-ion batteries, and how China came to be the great liberators of the last openly despised minority in America.

The only thing that saved me from an awkward phone call from the jail in Temple (I'd forgotten my cell phone, so my wife had no idea why I'm not already home) is that my eLiquid supplier (Blip Labs) is the *only* one who properly labels their goods, with the appropriate poison warnings, HazMat codes, and everything.  I'm pretty sure that without those, even my fanboy patter would not have convinced the trooper I wasn't up to something dodgy and needed to be hauled in until he figured it out.

--Dave

[Mrbloodworth]

So. I got my NO.7 in the mail yesterday, and basically i have only smoked about 3 smokes that day, with the help of this device.



I must say, while this attacks the need, it is still quite different experience than smoking a real one. I had ordered two units, one for me and one for a friend (I got the disposable version, with the 5 solution numbs). I get vapor most of the time, however my friend rarely gets anything.

I guess I shall see how it goes over the next few days until I run out. It  doesn't reproduce the full smoking experience, but I guess it is something. Cutting back on the number of real ones a day is a good thing.

[Ookii]

<Long story>

Scary! I kind of want a box mod, but things like this make me think it might be a bad idea.

Oh and Mr Bloodworth, buy a goddamn 510 already (35 bucks, cmon) and use the tea bag mod.  There really isn't any point unless you're doing that.

[MahrinSkel]

I've had exactly 1/4 of a cigarette in the last two months, Schild was convinced I'd go back to regular cigarettes if I tried them again last week.  Initial drags were okay, not anything to make me wax nostalgic, but the *aftertaste*.  Yuck, like I had licked the ashtray.

Keep in mind, I have none of the usual former smoker dislike for cigarette smoke, it doesn't bother me at all, and the initial taste and feeling in the throat were no big deal.  But if that's what my mouth always used to taste like, no wonder my wife wouldn't kiss me after I came in from smoking.  Didn't go away for at least half an hour, either.  I've got a pack of emergency cigarettes stashed in the freezer, but I'm hoping I never need them.

--Dave

[schild]

Of course, I didn't give him a menthol, so it probably did taste like an ash tray.

[Mrbloodworth]

<Long story>

Scary! I kind of want a box mod, but things like this make me think it might be a bad idea.

Oh and Mr Bloodworth, buy a goddamn 510 already (35 bucks, cmon) and use the tea bag mod.  There really isn't any point unless you're doing that.

Care to like a suppler I can order from? The reason I got the No.7 Is becomes it was a low investment to give this a try.

[Nonentity]

Wow, manual batteries beat the everliving shit out of automatic batteries.

I'm already mad at my usb passthrough because I can never tell if the goddamn thing is working right. WTB manual usb passthrough

[Nerf]

Drop me a PM non, I'll take care of you on the passthru.

For everyone else: I'm going to be ordering a bunch of atomizers and stuff for personal use from bestecig.com in about a week (China is on vacation this week, heh)

So - PM me what you want on their site and you'll get it at list price -10%, and the only shipping charge you'll need to pay is stateside ($2 for first class, $6 for priority in most cases)

They've got 901, 801, 401, and 510 kits, atomizers, batteries, and dirt cheap liquid.  If you like tobacco flavors, the 555 and mild 7 are my personal favs.  RY4 is nice too, and something that noone has really been able to duplicate DIY.  So even if you're doing what I do and mixing your own flavors using the cleaner blip stuff, the RY4 is fun to have around - it tastes kind of like cotton candy, but caramely..its odd, but good.  Cola is surprising good too, it tastes like smoking a coke.

Ordering from china is sooo much cheaper than stateside, so I highly recommend stocking up on atomizers - I think they wind up being like $5.50 or $6 per after the 10% off list.
They've got manual USB passthrus too, although they will die sometimes.  The ones I make are much higher quality, but I don't think I'm going to make anymore stand-alones passthrus, just fake batteries for the lasers to use it with USB.  Theres just not enough money in em to make it worth all the effort to build them.

[Stillwagon]

New guy, been reading the forums for a long time but I don't consider myself to be extremely witty nor am I a huge gamer anymore (job, life, etc).  In any event, I've been reading the forums since the wt.o merger days, which probably qualifies me as one of the most pathetic lurkers in board history.  I registered as a result of this thread, so I figured that I should at least post my limited experience with e-cigs.

So, Nerf hooked me up with one of his laser mods, a USB passthrough and various other accoutrement last week.  Since getting the e-cig, I really haven't had much of a craving for an analog cigarette.  It's not exactly a one-to-one trade off, but it's damned close and the benefit of not smelling like an ashtray is a big plus -- at least that's my wife's opinion.  I probably can't say much more than what's been covered in this thread already, but I would definitely advise a USB passthrough or something of that sort.  Powering via USB produces significantly more vapor which, having smoked analogs for 14 years, is closer to the throat hit that I'm accustomed to.

If you are a smoker and are on the fence about trying e-cigs, I would definitely recommend giving it a shot.  Particularly if you are in an area of the country (as I am) where analog cigarettes are insanely expensive, it's more than worth it simply from a cost-benefit standpoint.  So, I'll shill a bit for Nerf here and say that my experience has been really great so far and he definitely delivered what we agreed upon and more.  Ebay-style feedback: A+ seller, would use again.

One last bit of advice for those that wish to mix their own juice, there is a nice spreadsheet that was referenced earlier in the thread, but it can be a bit daunting if you are looking to mix a simple flavor.  I found a pretty decent and very simple online calculator for ejuice here.

[Slayerik]

I have nothing bad to say about Nerf's service, he was helpful over the phone and stuff. My experience overall was pretty meh. The juice tasted ok I guess, but hard on the throat (and I smoke Marlboro Reds)... and the juice seems to drip out. I gotta buy some chargers for my batteries...mix shit up....some of the equip was faulty.

I could see someone with more motivation than myself getting into it, but for me it's a little too much effort for a raw throat and money savings.

I know, I know....Tea Bag mod. I just don't even feel like trying :P

[Nerf]

Seriously dude, the teabag mod takes like 3 minutes and makes a huuuge diff.  Which liquid are you using currently?  If you're finding the throat hit too harsh in the beginning, step down to a lower nic level until you get accustomed to it, run more glycerin in the mix etc.  You've still got my cell number, call me tonight (after like 5pm CST) and I'll run through some shit with you and figure out if theres anything you're missing.

[Ookii]

You have to find something that suits you with vaping, some people like some models better than others, and some people like different vaping methods more than others.

I've tried the 801, 901, 510, and the be102 (or something, it's wierd), and I like the 510 the best with the teabag mod.  If I didn't use the teabag mod and had one of those other models, I would have probably gone back to cigarettes, it just wasn't as enjoyable.

[MahrinSkel]

Yeah, I hate the 901's because if you use the cartridges, you get liquid in your mouth, and I don't drip because it's too much hassle.  I've got a 1 year old, so I have to keep very close track of where my stuff is, and being able to load a cartridge and use that for 30-40 minutes at a time makes it a lot easier to keep the eyedropper bottles where the baby can't reach them.  The 801's don't give as intense a throat hit as the 510 or 901, but I actually *prefer* that, and it sounds like you would too.

--Dave

[Big Gulp]

Hey Nerf, I'm looking for a backup on my Janty Stick.  My concern is that if this one should die I'll become desperate, and like a crack addict, then do anything to score (namely, going back to actual smoking).  I like the Janty, but I've got some minor quibbles with it. My main complaint is that they don't draw very well if you're not hooked up to the USB passthrough.  This usually isn't a problem since I'm either at my computer, or sitting on the couch where I've got a power adaptor that has a USB port.  When I'm on the road, though, it'd be nice not to have to take 6 second hits to get the same effect as when I'm hooked up.

Is there anything you can recommend/sell me that meets this criteria?  Hopefully with at least 3-4 hours battery life?

[Nerf]

I could make you a laser in 510, the lower resistance atomizer makes up for the lower voltage (3.7v vs 5v from USB) from a battery-operated device.  2-4 hours between swapping batteries is about right for the 10440s.

However, the DSE905 is out now, and while its not available in anything but 901, it's a great product and it's dirt cheap ($65 for a starter kit w/ batteries, chargers, etc, etc)

I'm pretty much getting out of the making stuff business now that the chinese are doing it right, but if you really want a laser in 510 I'll hook ya up.

[Big Gulp]

I could make you a laser in 510, the lower resistance atomizer makes up for the lower voltage (3.7v vs 5v from USB) from a battery-operated device.  2-4 hours between swapping batteries is about right for the 10440s.

However, the DSE905 is out now, and while its not available in anything but 901, it's a great product and it's dirt cheap ($65 for a starter kit w/ batteries, chargers, etc, etc)

I'm pretty much getting out of the making stuff business now that the chinese are doing it right, but if you really want a laser in 510 I'll hook ya up.

Nah, if you can point to something else that fits the bill that'd be great.  Got a link to somewhere I can buy the DSE905?

[Nerf]

China:  http://www.healthcabin.net/dse905-wholesale-1046.html?zenid=riei49efor4e605tct6aersr05

US:  http://shop.vaporcountry.com/product.sc?productId=255

I'd send an email to any US suppliers beforehand to make sure they're actually in stock, a lot of e-cig sites are pretty fucking shady and will gladly take your money with no stock and keep feeding you bullshit til their order arrives.  Shipping from healthcabin is cheap, and their sales rep (Amy) is awesome.

[Big Gulp]

China:  http://www.healthcabin.net/dse905-wholesale-1046.html?zenid=riei49efor4e605tct6aersr05

US:  http://shop.vaporcountry.com/product.sc?productId=255

I'd send an email to any US suppliers beforehand to make sure they're actually in stock, a lot of e-cig sites are pretty fucking shady and will gladly take your money with no stock and keep feeding you bullshit til their order arrives.  Shipping from healthcabin is cheap, and their sales rep (Amy) is awesome.

Eh...   Still no USB passthrough, though.  Maybe I should just stick with the Janty?

[Ookii]

I'm all about the 510s, I would definitely look into one.

[Nerf]

No 510 (or other low-resistance atomizer) available for the 905 yet, only 901s.  You're stuck with non-china mods if you want 510.

[Big Gulp]

Okay, so I just ordered the new VP PT shipping on Monday.  5 volts of pure vaping goodness!  Now I'll just keep the Janty Stick around strictly for times when I can't be tethered to a computer/wall socket.

ETA:  I am bothered by the lack of 510 and 801 vaporizers available, but I'll live until they're a little bit more readily available.