Tried to make a USB passthrough. Help.

[Don'tReadTheRunes]

To start off, I have made a working nicostick so the basics of what I need to do are more or less understood.

I went to Radio Shack and bought a momentary switch (same kind recommended for nicostick). Then I went to the dollar store and bought a usb cable and a keychain flashlight thing that I was to use as an enclosure.

I strip the end of the usb cable and expose 4 wires. I clip the green and white wires down and just use the black and red. I plug in the cord and run the meter over them and I get 5.2 volts. That's good.

I then modify the keychain light by enlarging the holes for the battery connector and button. Next I solder the lead onto the center post of battery connector, solder other end to the post on the switch, then attach the red wire from cable to other switch post. I then solder black wire from cable to outside of battery connector.

I test electric flow putting the meter probes in the cavity of the connector to simulate the atomizer contact. I get 5.2 volts at that location when pressing the button and I think I'm golden. I assemble all the parts, screw in atomizer and I get nothing. Re-test and I'm still getting power to the money side, try different atomizer and still nothing. So I add a small piece of wire into the connector hole because I'm thinking that maybe my atomizer is not making the positive contact even when screwed in tight. Still nothing. Voltage flow is again good.

For USB power, I am using a wall plug in to USB adaptor. The sticker has it rated output of 5.2V at 1amp. Should be good right? Tried plugging into a regular PC based plug and still no joy.

Any advice?

 

[Dave Rickey]

Two possibilities occur to me:

1) Somehow both your PC and the wallwart are dropping under 3V when trying to push the current through the atomizer.

2) Somewhere in there you have a high-resistance connection (cold solder joint, nicked wire, crappy switch). With no current except the trickle through the meter, you get voltage, but when you try to run the atomizer, you lose all your voltage across that bad connection. Start taking *resistance* readings (with no power applied) across all of your contact points, if you get anything other than 0 or infinity, something's wrong.

If your meter can be calibrated, get it so direct contact of one probe to the other reads 0. If it can't be, note the ohm reading in direct contact and subtract that from your readings in the passthrough (my cheap Harbor Freight meter reads 0.6-0.7 ohms across a dead short).

--Dave

 

[Don'tReadTheRunes]

All my connections are 001 across every solder joint. The machine zeroes or is calibrated to 001. I should not be getting current loss.

 

[Dave Rickey]

Try taking loaded readings, seen if you're getting current, then.

--Dave

 

[Don'tReadTheRunes]

With current applied, I still get 5.09 volts at imput and output.



Assuming the physical connections are true, what would cause the atomizer to not register any activity when supposedly sufficient voltage and amplitude is supplied?

 

[Don'tReadTheRunes]

I'm checking and rechecking the connections and I can't find a logical reason why it's not working. Let's look at other possibilities: the usb cable i bought was a cheap one from the dollar store. Could it be that I need a specific USB 2.0 cable and I'm presumably using a USB 1.0 cable (there is no indicator as to version on the packaging)? Would that even make a difference when just using it for electricity? Second, how would I test for that with my multi meter?

Is it possible to show 5 volts AFTER the button and inside the connector where you screw in the atomizer while at the same time having no or greatly decreased amperage or current or whatever the mAh thing is? And how would I use my mm to test for that?

 

[rookie20009]

Had the same problem a month or so ago. Posted as you and had no solution.
Had 5.2 volts as yourself but no go when connecting atomizer.
Worked for several days with 3 diff atomizers, 3 diff atomizer connectors (2 bought, 1 salvaged), 2 diff wall chargers, dollar store usb cord and one I cut from a dead bought pass through....nothing.

Finally gave up for about a week and decided to try again. Measured 5.2 again but
this time for a reason, I still don`t know, it worked and is working as I write. I did end up using the salvaged usb cord.

Only thing I can think of is some atomizers just will not connect right and needs
the treads cleaned and screwed on real real tight but really don`t know.

If you ever figure it out I`d really like to know the cause...Good luck!

 

[Don'tReadTheRunes]

Thanks for the reply, rookie.

So often in my profession I have had things just 'start to work' and while it's cool at first (I can submit my bill) I'm always left underwhelmed because when dealing with electronics, logic should prevail and one should always be able to test or control for different things to isolate a problem.

I don't know if this thing will just 'decide' to start working or not. Which of course adds to the frustration.

 

[Drozd]

For USB power, I am using a wall plug in to USB adaptor. The sticker has it rated output of 5.2V at 1amp. Should be good right? Tried plugging into a regular PC based plug and still no joy.

Any advice?

I's been suggested in at least 2 PT threads that for some people and some PTs that 1amp wall plug to USB adapter just doesn't seem to work for them and the atty on the PT doesn't want to work..this seems to echo what might be going on for you..I guess their solution was to step that up to an adapter that puts out 5V at 1.5amp..

Guess this is what their using:USB Dual Power Adapter
puts out 2 amp if just using the one port

 

[Don'tReadTheRunes]

I's been suggested in at least 2 PT threads that for some people and some PTs that 1amp wall plug to USB adapter just doesn't seem to work for them and the atty on the PT doesn't want to work..this seems to echo what might be going on for you..I guess their solution was to step that up to an adapter that puts out 5V at 1.5amp..

Guess this is what their using:USB Dual Power Adapter
puts out 2 amp if just using the one port

Practically speaking, I have no problem tossing more cash at this issue with another adapter. That said, why would there be any difference between 1amp and 1.5 and 2amps? What I mean is, based on your suggestion, the difference lies in the nature of the adapter and not the current or voltage supplied by whatever means. Why would the amp rating for one power source be better or worse than another at the same rating? Surefire batterys works great at 900mAh, stock 510 battery works great at..what...250mAh? Less?

Experience of previous users could of course reign supreme however and I suppose I will buy another adapter if I can't get a handle on this. Also, I will try to find those passthrough threads to see if I can get a clue.

 

[Drozd]

Practically speaking, I have no problem tossing more cash at this issue with another adapter. That said, why would there be any difference between 1amp and 1.5 and 2amps? What I mean is, based on your suggestion, the difference lies in the nature of the adapter and not the current or voltage supplied by whatever means. Why would the amp rating for one power source be better or worse than another at the same rating? Surefire batterys works great at 900mAh, stock 510 battery works great at..what...250mAh? Less?

Experience of previous users could of course reign supreme however and I suppose I will buy another adapter if I can't get a handle on this. Also, I will try to find those passthrough threads to see if I can get a clue.

This I am not sure about...I only stumbled upon it myself when I was asking a question about something i was looking at as a portable power pack for a PT..and it's only mentioned in passing or alluded to:
.
Here's the link to the thread:
http://www.e-cigarette-forum.com/forum/puresmoker/50922-anyone-get-their-ps-usbpass-v2-yet.html round page 5 or 6
I don't propose to know the answer or even understand all the electronics involved ...just passing along something I saw on another thread that was made mention of that may coralate to the problem you're having

 

[Wireguy]

The amp rating on the adapter is how much amperage is available all a once, always. The mah is how long a given amperage will be available. Millie amp hours.

How did you handle your ground?

If you have another power source like batteries 3 aa for example you could hook that in and that will give you your answer. If it works it's your adapter, if not you have high resistance in your build.

 

[Don'tReadTheRunes]

How did you handle your ground?

Um..what do you mean by ground? What would be a ground? in the setup I mentioned. Let's see...the case I used is 100 percent plastic since I took out the battery contacts because those were just for the stock pill shaped batteries, plus a passthrough needs no batteries. I'm intrigued by this question however....

If you have another power source like batteries 3 aa for example you could hook that in and that will give you your answer. If it works it's your adapter, if not you have high resistance in your build.

I had not considered this...will try this out and see. Wait i did consider it...just now realized I do not have to unsolder my current connections to try a different power source.

 

[Wireguy]

I just reread your first post. You said what you did with the ground, I just didn't see it. The ground is the black wire.

If your going to be doing this a lot these make testing easier.

14" (35.3cm) Insulated Test/Jumper Leads - RadioShack.com

 

[Dave Rickey]

The amperage matters because an eCig at 5V is going to be drawing 1.5a (801) to 2.5A (510). Under-rated wallwarts will respond to this demand in one of three ways, which depends on the details of their design:

1) Provide the full current at full voltage, with heat and stress on the components in the wart.

2) Drop or flutter the voltage so that current stays within its safety cutoff (which may be slightly over the rated capacity).

3) Simply not work, engage the safeties and provide no current.

It does seem like somehow you're not getting a good atomizer connection, or just happened to have had bad atomizers (have you checked them on known-good sources since? Sometimes 5V will blow an atomizer that was working just fine on battery power).

--Dave

 

[Don'tReadTheRunes]

The atomizers are good. They work on normal stock batteries after being tried on passthrough attempt. Physical connection between atomizer and connector is the only thing I can't verify even though I did attempt to bridge the hypothesized gap between the center of connecter and bottom of atomizer. The threads being the ground are pretty certain to be a true contact.

 

[Dave Rickey]

Then I'd punt: Tear it completely apart and rebuild, or build a new one to the same design from different components.

--Dave

 

[opuscroakus]

If your going to be doing this a lot these make testing easier.

14" (35.3cm) Insulated Test/Jumper Leads - RadioShack.com

Thanks for posting this. I have been meaning to get some and this reminded me.

 

[Wireguy]

They are one of those things that sit around for a year never being used then wham. Test time or test rigs Worth the price when you need them.

 

[Don'tReadTheRunes]

They are one of those things that sit around for a year never being used then wham. Test time or test rigs Worth the price when you need them.

Well put.

I found some and used them substituting the usb power source with the nicostick battery mod. The atomizer worked in that scenario which of course isolated the AC to usb power supply as the culprit. I had already taken the opportunity to follow the advice of ordering the usb power converter suggested a few posts earlier just in case. Good to find out I was correct in doing so (with help). I suspect that the particular power unit that I have clips or just shuts off when the atomizer attempts to draw over the amp rating of the power supply.