USB passthrough w/charger mod

[mogur]

Yeah, you can buy these commercially, but then I wanted to do it my way. This project started because I ordered a few 901's and one of them came with a usb charger with a male connector for the battery. Well, 901 batteries are male, so this amounted to parts for a mod-

The $4 charger wasn't worth sending back, and I had several chargers already. Here's what I received-

And here's what's inside-

So, I gutted it-

And decided it would make a good battery-backed USB passthrough-

First, I needed to carve out a hole and recess for a tact button-

Then fill the passthrough with parts-

And score a double AA battery box from the idiots at Radio Shack-

French in a DC panel power jack (Ala Nico), and notch for the strain relief-

Then I had to shave down the charger PCB to fit in half of the battery box, using a table saw. That outer -IN trace isn't necessary, since the other end of it is available for soldering to the wiring in the box. While I was there, I notched the strain relief from the USB end of the cord and got rid of the original PCB connector-

I brought back the remainder of my fingers from the table saw, and stuffed the battery box-

After waiting 5 years for DX to send me a 14500 li-ion, we're ready to vape-

Voila!

Before you ask me why there are two holes in the battery box, there is a very good reason. The second hole lets me see if someone stole my battery without opening the box. I call it a dyslexia hole, after the medical condition shared by smart, good-looking, well endowed people.

I haven't finished the USB cable yet, but it vapes just like a 901 with a fresh battery, duh. I will report on the charging part of the circuit after a few weeks of experience.

 

[balldope]

Mogur, NICE!!! Great detail on the schematics. Let us know who it goes.

 

[mogur]

Mogur, NICE!!! Great detail on the schematics. Let us know who it goes.

I see you're smart, good-looking and well-endowed, also. Grin.

 

[Evilfezdog]

and generous dont forget generous

 

[balldope]

I see you're smart, good-looking and well-endowed, also. Grin.

Yeah, a little dyslexic today. Forgot who I was looking at your mod. All sorts of mods started running through my head...

 

[Kewtsquirrel]

Mogur, with the 2 capacitors inline, whats your output voltage to the atomizer?

 

[Cisco]

Mogur,

I think that is so nice you need to make it twice...hint..hint

Awesome job, can you give a few more details on the electronics..

Cisco...

 

[mogur]

Mogur, with the 2 capacitors inline, whats your output voltage to the atomizer?

Both caps are always connected to the li-ion cell, so they will charge to almost the exact voltage the cell is currently outputting, ie 3.3 - 4.2 volts. Their purpose is to mellow out the surge in amps when the coil is first connected. They aren't required, but I have been conditioned to add them from audio amp and power supply design experience, especially if the load is not located right near the power source.

Cisco, the idea of this mod is to primarily be a usb passthrough while sitting at the computer, which is most of my life, now. The cell has two purposes. It is meant to supply the ~1amp current for a few seconds, then it gets topped off by the usb in between puffs. This reduces the current demand from the usb to about 100 mA, low enough that any computer, laptop, tiny wallwart, or even a 5 volt battery pack can handle.

Second, on the occasional forays into 'America' (off island), I can unplug the battery pack from the usb cord with a freshly charged 750mA li-ion to depend upon. The umbilical cord is not very elegant, but hey, something that works if all the pretty ones aren't handy. Or, more commonly, I can carry it into the bedroom for a few hours of tv watching.

I've seen these commercially available from a couple sites, but the truth is I wanted to learn more about it, and nothing works my memory more than having to do it myself.

Edit PS: Oops, the drawing is missing the neg lead from the capacitor to the common gnd in the passthrough. Fortunately, the actual lead did get soldered in.

 

[Paradiso]

Wow, that's great. You really know your way around circuits!
I had posted in the battery mods section asking about something along these lines.
My idea was to integrate the charging pcb, as you have done and adding a switch that would (in my mind anyway) allow you to select whether the USB was either charging the battery or powering the atomizer.
I'm thinking of a NicoStick that could run off the battery OR run off the USB power (with a diode to reduce voltage) OR charge the battery.

Does that make sense? If so, could you offer some input about how I might go about wiring the switch (and perhaps what kind of switch I should be looking for)
Thanks
John

 

[mogur]

Wow, that's great. You really know your way around circuits!
I had posted in the battery mods section asking about something along these lines.
My idea was to integrate the charging pcb, as you have done and adding a switch that would (in my mind anyway) allow you to select whether the USB was either charging the battery or powering the atomizer.
I'm thinking of a NicoStick that could run off the battery OR run off the USB power (with a diode to reduce voltage) OR charge the battery.

Does that make sense? If so, could you offer some input about how I might go about wiring the switch (and perhaps what kind of switch I should be looking for)
Thanks
John

Great idea! I have been thinking along the same lines, myself. This mod runs off the battery AND charges at the same time, so there is no need to switch between them. To run off the battery alone, unplug the usb cable. To charge, plug in the cable. To act as an usb passthrough, leave the cable plugged in and you can vape while charging. So I see no problem combining the passthrough and battery box into one box, but I think a triple instead of a dual AA box would be necessary for all of that circuitry (and half an atomizer) in one box.

I don't quite see why a separate usb passthrough with dropping resistor would be desirable, but I'll assume you have your reasons. I would suggest using a double throw slide switch to choose between battery voltage or usb voltage to the atomizer.

 

[Paradiso]

Thanks, Mogur, for the reply.
You're right, screw the switch. Just one more level of complexity that isn't necessary. Seems that if I mounted the atty where your PT wire is coming out, trimmed the pcb a bit tighter, lost the capacitor and found a smaller power jack, maybe I could find room for a tact switch. (!!!!)
I'm thinking I'll make this for the 510 atty, as I'm really liking the 510 a lot. It also has the benefit of allowing me to pretty much surface mount the connector, saving space in the box.

I wanted to reduce voltage because the first PT that I built was for the 401 atty and I burnt up 3 attys in short order with straight 5 volts. The 510 and 901 attys are more robust, so maybe I don't need to limit voltage.

If I can get this working it would be sweet. I imagine driving with it plugged in to a usb adapter in lighter socket. Vaping away while I'm driving, then when I get where I'm going I can just unplug and have a fully charged battery!

 

[wegster]

This is very nicely done.

How did you manage the recess? Use something heated to depress into the old charger case, then drilled for the button, or ?

Did you think about making the manual PT portion plug in via USB into the charger box, then you can just vape directly from a wall wart (USB), if desired?

Very nice. I do wish all PTs came with a plug-in inlines optional battery, like your charger portion of it.

 

[mogur]

Thanks wegster, appreciated. If I still had my milling machine..... but, alas, I only had a 3/8" handheld drill motor to work with. Drilled out the original led hole for the tact switch button first, then just scraped with a sharp pocket knife to create the tapered recess. Primitive, but it wasn't production, so I just took my sweet time about it. That plastic is thicker than it looks, I didn't need to heat it up and push inward, just scraped until it felt right. A little fine sandpaper made it look less ghetto. But at the very end, I screwed up a little and got a some epoxy around the button. By the time I scraped that out of there, a few knife scars were left behind. Nothing a little sandpaper won't cure, but now I'm too lazy.

 

[mogur]

Did you think about making the manual PT portion plug in via USB into the charger box, then you can just vape directly from a wall wart (USB), if desired?

This mod was meant to vape while plugged in (usb, wall wart, car, anything with a usb receptacle). The battery and charger are thrown into the design for those occasions when I want to use it as a portable. The battery is always suppling the immediate power, so it is taking the brunt of the high current demand, without requiring a full amp out of the USB port. The USB port just tops off the battery between puffs at about 100mA. An absolute direct USB connection, therefore doesn't seem to me to have any advantage, unless you need a full 5 volts for best vaping. My 901 atomizers burn up at 5 volts, so I am happy with the nearly always 4+ volts out of a fully charged 14500 cell.

The same question was asked earlier, and unless I'm not understanding the question, I think I might have confused the situation by not showing the USB cable from the battery box. I have the dc power plug and a bunch of old USB cables lying around, but I haven't made it up yet because I'm still looking for a USB cable that is small dia, soft and flexible.

 

[rbonie]

Got no pics... dunno why... can you email them?
rbonie@gmail.com

 

[Guitarslinger]

Damn-been looking for this info but now that I found it-nothing here??? lol

 

[xeir]

Noticed that myself. Found a handy thread, and the pics are a no go.

If anyone has the pics lying around, it would be most welcome to pop them back online.

 

[Bingo Mion]

n pics poo