Homebrewing a usb passthrough, question...

[Fox3]

Hi Folks,

I've got a couple 510 auto batteries that are HOT and run for a while (3-4 sec)and I am thinking of trashing them and converting them into passthroughs to have in a couple places. Not sure about it but I suspect that those are what was responsible for trashing two atomizers in just over a week.

I'm now using only the manuals and hopefully that will keep my atomizers running in the second 510 I got.

I notice that the batteries are 4.2V peak dropping to 3.7 until they run out. USB outputs ~5VDC. The 510 gives a very decent vape with the manuals so I am thinking that something like a 1N4004 inline with the positive lead would give me 4.3V which would be easier on the atomizers? Maybe two diodes for 3.6V?

I don't think that I need any current limiting?

Also, the switches that will fit in the barrel seem to be rated at 30 or 50 mA which would seem to be WAY out of spec (expect 0.5-1A from the port with the 2A Wall wart that my hub came with).

Comments appreciated! Thanks!

P.S. Reason I am being careful on this one is that I went direct to the port for an 801 I had with a well used atomizer and the atomizer went west on the first pass. Waiting for new 801 atomizers to try again.

Also, thinking that a jack to plug in a foot switch might be nice .

 

[lewnworx]

I had a DOA 510 batt that I converted into a usb passthrough.

I did a simple single resistor voltage divider to drop the USB to 5.2 VDC, found a small momentary switch to use as a manual, and cut up a USB extender for the cable.

I pushed out the battery mechanism via a drill press with a same diameter pin in the center hole, soldered a lead on to that (and filled the hole in the process to avoid ejuice getting into the rest of the bit.

I dremeled out a notch on the far end of the battery to make a slot for the switch to slide in, soldered the mess up, and put a couple layers of shrink wrap on it to finish it off.

I've been driving it with an APC mobile power pack (1800 mAH) and it's gone for 3 days on a single charge. It took a couple hours to do.

Works like a champ.

 

[Fox3]

Thanks for the response, but a couple questions, if I may?

USB is supposed to be 5V anyway, are you sure that resistor is not functioning as a current limiter? What value / wattage did you use? IIRC it takes two resistors to make a voltage divider. Unless you are using the coil somehow as another resistor? Yes, I'm confused here :-/.

What did you use for a switch? The ones I have found that would fit are not even close to the current rating expected. I was going to use something huskier in the cord but that is going to be klunky.

Good idea on the heat shrink, I was thinking of filling the back end with hot glue, heat shrink would be MUCH easier to get off if repairs were required.

Drill press idea also great . Got my 801 apart with some solder picks and a knife to get the glue loose / out. Your method sounds MUCH easier and less messy !

Thanks again!