USB passthrough safety question..and one other ?

[nin_brokenhalo5]

OK..this may sound ludicrous, laugh at me all you want, I am a n00b, but it has been on my mind for a few days as I await my first USB passthrough for my DSE 901. I have been vaping for about three weeks with standard manual batteries.

Scenario: You are happily vaping away while plugged into a USB passthrough on your laptop with the computer power charger connected. A thunderstorm suddenly enters your area and a bolt of lightning sends a power surge through your computer while your e-cig is in your mouth. This question applies to any sort of surge from any root cause. I live in an old apartment building and surges are common, especially in the summer.

Any danger of electric shock there? Could you imagine that? Has this ever been brought up even?

Just doesn't seem to be the wisest idea to have a device in your MOUTH that is connected to a computer when the risk of a surge is high.

I would assume the least risk would be to vape with the USB passthrough on a laptop that is disconnected from a power source or plugged into a surge protector.

Thoughts?

Also, another possible silly question:

Any issues using a mac book pro with most USB passthroughs? Has anyone ever reported one NOT working on a mac?

OK...now I slink away a bit red-faced but hoping for interesting feedback LOL

Kind regards,

NIN

 

[Papa Lazarou]

Well a similar risk would apply if you were typing on the laptop at the time I would imagine? I suspect the laptops power supply would take most of the damage (and may well be destroyed) but the risk of high voltage going through the transformer, into the laptop and out of the USB port is probably quite low. But that's just my inexpert, non-electrician opinion. Using a quality surge protector is probably a reasonable solution to this concern (it would be wise to protect your electrical items anyway) but I must admit I hadn't really thought about it

I would suggest using a 2 Amp AC/USB adapter for using with a pass through - especially a 5v pass through. They can draw way more power than most USB ports on computers can provide, and there have been cases of this causing damage to the PC. The safest pass throughs to use on computers are the type with a battery built in (for example the genuine Joye 510 pass throughs) as these have a fairly low current draw.

 

[Hoosier]

Is your senerio possible? Yes, but the odds are really against it.

As mentioned the likelyhood of burning out something in your computer is much greater. The USB standard is independant of the computer manufacturer. The standard USB has to supply 0.5 amps at 5 volts. If you do not have a battery between the port and your atty we can plug the USB standard into V=IR, or better yet R=V/I to find the perfect atty resistance of 10 ohms. That is much higher than standard attys, so something has to give. What gives may be the motherboard which is really bad. Even if just the USB bus gives, that is a pain. At best you will stress the circuit that controls the USB bus power which will lead to failure sooner rather than later.

Follow the advise given above, if you do not have a battery in your passthrough, get an AC to USB adapter. It is cheap insurance against computer problems.

It will take a good quality surge protector to handle lightning though and even then they are not 100% safe. (I design structures to protect elecrical and communication equipment and even with redundant systems and special grounding schemes, I would not consider them 100% safe, but I wouldn't be frightened to be in one of my high voltage structures during a storm because the odds are very small.)

 

[Kurt]

Just to add my $0.02, I have fried a port with a standard 510 batt-box PT, and also a port and a couple USB cables with a Bartelby, which USB-charges a 14500 battery VERY fast, thus a big current draw. I have a 510 5V PT and a Hello Sit and Go PT, and I will not plug them into anything but an external powered USB now. No problems at all with PTs now. The selling points that many vendors use for being able to vape right off of your laptop is definitely risky. I also recall someone here frying their mother board with a standard 510 PT.

You can get a killer 2 Amp AC/USB converter with a long cable from RadioShack for ~$25. There are many cheaper ones available that you just plug into the mains and then plug the PT into them, which run around $10 or less. I have found that they tend to die faster, so I just go with the beefy RS one.

As for the lightening this, it sounds like Hoosier knows what he is talking about, and I agree: surge protectors are your friends, for all important and expensive electronic gear.

 

[rolygate]

One thing that can be said about lightning strikes is that they are unpredictable - what happens in one case may not happen in another. I know several people who have been in houses and boats struck by lightning. The safest place to be in a storm is in a car, it acts as a Faraday cage and you are totally protected, even the car's electrics will normally survive a big hit - the charge just flows over the car and down to the ground like water. Boats aren't so good, there are too many paths to ground through the structure, and all the electrics will be fried, often the batteries get melted to junk.

In a house there are, or should be, several paths to ground, so people inside are normally safe. The danger comes if holding electrical devices very closely - in other words, a strong physical connection between you and the device - as the path to earth is better. I know a guy who was talking on the phone when there was a strike about 50 yards away that hit the overhead phone cable among other things. The surge came right through to his phone and he got hit, he was knocked across the room and got a small burn on the side of his head. He was OK when he woke up though. This is extremely rare where I live, phone engineers with decades of experience had never heard of anything similar.

If you have underground power coming into your house, it's unlikely that any lightning strike on your house will involve the power circuit, though not impossible. A surge can bridge the power, phone, and cold water supplies in some cases, as the voltage and current is so high that normal earth provision is not sufficient. Every house I live in, I install a new, separate earth rod, just to make sure there is a good earth. You can't have enough. Mainly this is just to make sure the electrical earth works correctly, as that means better safety. Yes, it's kind of weird to find someone who does that in the city - but I have a mains earth resistance meter and when you look at some of the values you get, the earth provision is not optimal sometimes. Better safe than sorry.

If you have overhead power lines coming into your place, and if it's not really a built-up area, and if you get more lightning than normal, then it might be a good plan to install at least one more earth rod. Get a large one, not a small model (you normally get a choice), and get the thickest cable you can carry, to attach it with. Thin cable is no use.*

You should earth out your mains supply earth connector where it comes into the house. If you do the job properly, you'll also earth out the cold water supply where it comes into the house. This can be a problem if you have the new plastic piping, you might need to go to the first heavy metal fitting in line. Also the gas supply, if you have one that comes in in metal pipe.

If you do this then you've done what you can. A prudent person would still disconnect all vulnerable electrical equipment in a storm, though. Yes, the insurance might reimburse you - but it can never pay for the aggravation, especially if you get wiring burnt out. You might also want to keep away from power sockets and water line connections like sinks and baths, if you live in an area where houses get hit regularly.

There is no normal way to disconnect the power supply if lightning is around, the power is so high it can leap small gaps like switches and breakers. You would need to remove a yard of cable or something to make an effective break in the circuit. The best alternative is multiple good earths. Surge protectors are an excellent idea, but keep in mind they depend on your earth connection.

Having met the phone shock guy, I wouldn't be sucking on a PT in a storm, even with my extra earth rods...

* Some tips for installing an earth rod
- Use a heavy copper rod with a bolt terminal.
- Attach heavy clamp-on ring tags at each end, these have to be clamped on with a special tool, but heavy pliers or a mole wrench will do. Then solder it as well. Attach with bolts, not tiny screws.
- If you want it to work well for lightning, keep the cable run straight, with no sharp bends.
- If in a lightning-hit prone area, use the heaviest cable you can afford - for example 25mm or even 50mm.