PV Pak Preview

[Laredo7mm]

Well, I think this is going to be my next project. The design is pretty much done, but I still need to do a few tweaks here and there. Parts are on order. Let me know what you think.

Highlights:
1. No mechanical switch
2. Boost converter output of 5 volts
3. Battery fully protected from over charge/discharge
4. Battery does not need to be removed for charging
5. Can be used while charging


Here are some specs:

Case: Black anodized Aluminum
Size: About the same as the 4AA RS box
Battery: 2000mah li-poly
Output voltage: 5 volts
Output current: 3 amps max (battery PCB limited)
Over charge protection: Yes
Over discharge protection: Yes
Over current protection: Yes
Switch type: Touch
Remove battery for charging: No
Charger connection: DC Plug

 

[kinabaloo]

Like the touch switch. Did I inspire that?

The battery is a nice big capacity - 2Ah.

 

[Iken]

Thats a sweet Pak, What kind of atomizer are you aiming for? The pic seems like 901 but never hurts to ask. Is your touch switch activated by the heat of touch?

 

[Laredo7mm]

Like the touch switch. Did I inspire that?...

Um, yeah, sure. I don't know what the correlation is between you and touch switches, but whatever.

..Is your touch switch activated by the heat of touch?

No, when you place your finger over the two metal buttons, you are completing the logic circuit to turn on the mosfet. Don't worry though, it doesn't hurt...much.

The required current to turn the logic on is only like one pico amp so you won't feel a thing.

 

[MoonMan]

That's a pretty good idea for a switch.

 

[luvmyvapor]

Sweet!!!

 

[nicowolf]

No, when you place your finger over the two metal buttons, you are completing the logic circuit to turn on the mosfet. Don't worry though, it doesn't hurt...much.

The required current to turn the logic on is only like one pico amp so you won't feel a thing.

So, if I could cover both buttons with one finger, it would activate, no force or pressure required? That circuit board looks more intricate than I want to get into - from the standpoint of trying to do it myself or repair it myself, not from the standpoint of whether or not I want to own one.

The features sound like a dream, almost too good to be true. Any chance of making the form factor more vertical and less horizontal - just an aesthetic idea, not really about function at all.

Overall: How soon can ya do it? When can I order one? Will ya make adapters for the 510? What will it cost? Who will manufacture it? I WANT ONE.

 

[Laredo7mm]

Well, my first design was smaller, using a case that was only 12mm thick (9mm inside), but then it is havoc trying to fit everything inside. That was even going with a 8.4 volt 1300mah battery pack with a voltage regulator down to 5v.

To get taller and skinnier, the next step would be about 90mm tall based on available li-poly batteries, but then I would have to find a different case, and the case is the hardest part to find. This whole thing has been a bunch of compromises to get it into an exceptable form that doesn't require too much modification of any one part.

I just got the IC today. The IC is the component to the lower left of center in the above picture. Yeah, the one with 16 pins. Each pin is only 0.5mm wide, so I better practice up on my soldering.

When will it be ready? Hopefully in a couple weeks. I need to change the circuit a bit to fix a couple mistakes. After that then I just need to try to make the PCB and then start soldering.

Yes, the switch is activated by covering both of the little buttons next to the atomizer with your finger, In that picture, I think I have them set at 5mm apart. Very little pressure should be needed, but this is all theory, and electronics are not my strong point.

This is designed for a 901 atomizer using m8x0.75 threads. Which by the way, I am making that adapter also. What size thread does a 510 have?

Currently I am going to manufacture this prototype. I have not given any thought to people actually wanting to buy one, but if a demand develops, I can figure out the details from there. Component wise, the price is at about $60 for this prototype. That doesn't include the battery charger.

 

[Iken]

LOL @ Nico
Its like one of those fortunate teller machines. "Fortune for a quarter, I Love quaters!"
That thing is completely amazing, I Definitely WANT one. Thats the greatest saftey idea to date. Laredo please keep us informed. When you make process

 

[nicowolf]

Well, my first design was smaller, using a case that was only 12mm thick (9mm inside), but then it is havoc trying to fit everything inside. That was even going with a 8.4 volt 1300mah battery pack with a voltage regulator down to 5v.

To get taller and skinnier, the next step would be about 90mm tall based on available li-poly batteries, but then I would have to find a different case, and the case is the hardest part to find. This whole thing has been a bunch of compromises to get it into an exceptable form that doesn't require too much modification of any one part.

I just got the IC today. The IC is the component to the lower left of center in the above picture. Yeah, the one with 16 pins. Each pin is only 0.5mm wide, so I better practice up on my soldering.

When will it be ready? Hopefully in a couple weeks. I need to change the circuit a bit to fix a couple mistakes. After that then I just need to try to make the PCB and then start soldering.

Yes, the switch is activated by covering both of the little buttons next to the atomizer with your finger, In that picture, I think I have them set at 5mm apart. Very little pressure should be needed, but this is all theory, and electronics are not my strong point.

This is designed for a 901 atomizer using m8x0.75 threads. Which by the way, I am making that adapter also. What size thread does a 510 have?

Currently I am going to manufacture this prototype. I have not given any thought to people actually wanting to buy one, but if a demand develops, I can figure out the details from there. Component wise, the price is at about $60 for this prototype. That doesn't include the battery charger.

Wow, you have a LOT of time and thought invested in this already. I am in awe. Electronics not your strong point? In the world I inhabit, the electronically challenged do not make their own circuit boards, much less design them, and certainly not with that many doodads attached. In my eyes, you are an electronics mastermind.

Vincecadc posted somewhere what the threads were for the 510. I didn't tuck the numbers away in my mental vault because I am much too lazy to ever try to make one myself. I just carry mine around and compare to threaded objects everywhere I go, hoping to win the thread jackpot.

Soldering to pins half a mm wide? I hope you have a mouse trained to solder cause that's gonna be tiny.

Anyhow, this is a very ambitious mod. I am thoroughly impressed and looking forward to being your beta tester - wink wink.

 

[Flitzanu]

oh wow, big showoff!!!



i'm just jealous that i can't do stuff like this. good luck!

 

[MoonMan]

To any modders out there interested in this type of switch, I have seen it used on little stuffed Easter chicks. They "peep" when you hold them in your hand due to two little contacts on the bottom.

Find one of those, hook up a relay to it and you have a ready-made switch circuit.

 

[RaverCJ]

Laredo7mm, that is by far one of the coolest mods I've ever seen! Please post once you get the final version up!

Also, I was wondering if you had any idea how many recharge cycles the battery will be able to go through? I'm just wondering, because it seems like it would be much harder to replace than boxes like the Janty stick that uses simple 10440 e-cigar batteries.

Great job though!

Chris

 

[Laredo7mm]

...Also, I was wondering if you had any idea how many recharge cycles the battery will be able to go through? ...

The battery I am using says it is good for more than 500 recharge cycles. The 2000mah rating is measured after 300 recharge cycles. The boost converter is about 90% efficient, so on the conservative side, lets say a fully charged battery has an efective 1800mah after inefficiencies of the boost converter.

I am currently using a 1200mah device and the charge lasts me 3.5 days. An 1800mah device would last me 5.25 days between charges, so lets use a nice round figure of 5 days. To get to 500 recharge cycles it will take me 2500 days or 6.85 years. I use about 1.5ml of liquid a day, so if you vape more or less than that, your numbers will need to be adjusted.

The battery will be easily changed out. It connects to one of the two prong white connectors seen in the picture. Just unscrew the caps, disconnect the connectors, replace the battery, and reconnect.

Hope that helps and thanks for all the nice replies and interest.

 

[kinabaloo]

Um, yeah, sure. I don't know what the correlation is between you and touch switches, but whatever.

Just that i posted it as a suggestion a few days earlier. Nice when someone runs with an idea. Not exactly a new technology but had not seen it in a mod before. Best to test the circuit on a breadboard to determine best sensitivity and to make sure it will definitely switch off on release.

Tweety bird and relay: right lines to suggest a relay as it wouldn't handle the power directly. However, even a relay coil takes a fair bit of power and they are not easy to find at circa 4v. So a power transistor or mosfet (best as smaller) would be better.

Thought about how a touch switch could offer power settings. Simplest by using say three contact sets. Touch would fully activate first stage and then switch a particular control current to the main mosfet (so only one needed). Just an idea.

 

[MoonMan]

Tweety bird and relay: right lines to suggest a relay as it wouldn't handle the power directly. However, even a relay coil takes a fair bit of power and they are not easy to find at circa 4v. So a power transistor or mosfet (best as smaller) would be better.

Don't they make tiny solid state relays? Sorry, electronic components aren't my strong point. I'm lucky to understand relays in the first place.

 

[kinabaloo]

Moonman - well, yes; same, mosfet transistor (usually) all built into a relay-like unit - so one can more or less think of it and use it just like a relay. They are true relay-like in having separated electrical systems, optocoupled, though that's not required here.

There are mini, IC -like ones such as these: http://www.vishay.com/solid-state-relays/

And power types such as these (chunkier, traditional relay looking): http://pewa.panasonic.com/pcsd/product/ssr/index.html

To handle 1A would require something more like the second type (though those Panasonic ones are way over spec). However, because the electrical isolation is not needed and these things are prety expensive, just using a mosfet would be more appropriate in a VP.

Mains handling versions also exist that use a triac: discussion of, with example circuit: http://www.uoguelph.ca/~antoon/circ/solidstate.html

 

[Laredo7mm]

kinabaloo, good information you are giving. I was looking at mosfets as using them for a touch switch and then I started looking for a boost IC. When I saw the spec sheet for the IC I am using in the PV Pak, and once I figured out what they ment by logic hi and low, I knew I was good to go.

Anyone have any good tutorials on how to etch a PCB board? I have found a few on the net, but I was hoping to find a tried and true method.

 

[tribalmasters]

Bloody want one!!!! I have seen and used those switches before, great idea putting them into a PV device!

 

[tribalmasters]

What about using a real relay!? The click would be very satisfying!