USB charge port for iPhone/Smart Phones/Tablets

[shuttershadesrule]

Yes, I realize that there are versions of this that many companies who make accessories for people with disabilities have. (That's actually what lead me to this page.) I already reviewed the entire thread before I made that comment, thanks. Where I live the companies price these things at an inflated price (at least $40 pre-made) - and with the nearest one selling on Ebay being from Australia (still $40+) - ...with the amount that I'm looking to buy, I didn't want that to my first option, especially if I could figure out how to make my own. I now see that that's not going to happen but I appreciate your time commenting.

[Burgerman]

How many are you needing? There are people on this forum that may do this for you.

I would have thought that if you cant do this from that very clear web page a video isn't going to help. It really is basic stuff if you are the sort of person that can use a soldering iron. I doubt I could add anything with a video. And I would need to make another that I don't need.

[speedywheelz123]

Well, just finished mine! I took a different approach, connecting a Female cigarette lighter which the car charger can plug into. And other 12 volt devices that will work on 24 volts.
I have Pics!

[Fulliautomatix]

Didja put a fuse in it?


I see mine are $27.41USD + $6.30USD postage - which will cover 4 items - with the current exchange rate.
So $33USD for 1 delivered, $116 for 4.

21.36GBP for 1.

How many do you want? I'll do 10 for $25AUD each + $16AUD postage.

[speedywheelz123]

Are you asking me if I put a fuse in it? No I did not, the Phone car charger part is tho, so worst case, $10 car charger burns up. Or maybe wheelchair . But all seriousness, I trust my soldering.

[segreen]

Alternatively why not one of these? http://www.ebay.co.uk/itm/390855805297?_trksid=p2060778.m1438.l2649&var=660250412938&ssPageName=STRK%3AMEBIDX%3AIT

Steve

[speedywheelz123]

That certainly is a good option, especially if you want a more permanent solution. I just did it my way because I didnt want a permanent fixture mounted to charge my phone. Also, it seems silly to permenatly mount something if it still wires into the controller. You could hook it up to a single battery, that causes uneven battery drain.

[segreen]

Wire it up in series at 24v. It'll still give you 5v and 2.1 amps to charge your phone or whatever if I understand it correctly.

[Burgerman]

Yep. But 24+4v is lower than the charging voltage so probably best to only use it when not charging the chair.

(Or feed it via a couple of series diodes. To lose 1.5v)

[segreen]

Would anyone be charging their phone or any other accessory while charging their chair? Small prive to pay if a 12v & USB accessory socket was your prefered choice, I think?

Incidently John, if you were running a chair at 24v (I know your now on 48v) but would you bother with a 24-12v dropper or would you just use a 12v & USB accessory socket like I've suggested?

Steve

[Burgerman]

Well 3 of my 4 chairs are 24V. So I just use my home made thingy.

But on the Roboteq 45V chair I use its on board 10A 12V inverter to give a 12V supply (with a 3A fuse) to supply 12V for any extra stuff like that. It is really there to provide 12V for brake, LED lighting. But it takes a tiny 6 to 9 mA even if left on at all times.

You could also use one of these to power a 5V USB or a 12V Ancilliary output directly:

http://www.ebay.co.uk/itm/LM2596-DC-DC- ... 5d5502ce1b


http://www.ebay.co.uk/itm/4-5-40V-to-0- ... 4ae4c7e342

Many options.
BUCK = Drops volts only to whatever it says.
BOOST = raises voltage to whatever it says.
BUCK/BOOST = it can do both.

CC or CC/CV also, means you can set a fixed max Amp level. http://www.ebay.co.uk/itm/LM2596-DC-DC- ... 2589b6635d

So you cannot short it out or blow it up and is safe to use to set a fixed voltage and choose a current level, to charge or maintain your batteries directly.
You could for eg use a wall brick to get power. And make a battery charger or a battery maintainer. Set to 14.1, 14.4, or 13.3v for long term storage float. Same for your car or van.

http://www.ebay.co.uk/sch/i.html?_odkw= ... =&_sacat=0


http://www.ebay.co.uk/sch/i.html?_odkw= ... =&_sacat=0

[trishf]

hi i was just wondering if its possible to run a heated car seat cushion through the same cigar lighter and if so how much it would potentially deplete the battery on the chair ..i was considering using a smaller 12 volt ATV battery exclusively for the seat warmer??? ....its for my daughter i live in Canada and its already almost too cold out for her to even travel to the corner store i have everything already to hook up the cigar lighter and of course the car seat warmer is for a car cigar lighter. Also there is a fuse built into the plug on the seat warmer but i do have an additional inline fuse that can be wired is it necessary to have both or will the one in the plug in suffice? ty any and all suggestions are appreciated!!
Trish

[Burgerman]

It depends how many watts it is. Or if you prefer how many mA or Amps it draws.
Do you have any specs?

I would expect it will need about an Amp or So.

In which case it can work, but depends on the actual USB adapter you use. But if it takes more, then there are many cheap options. USB is only 5V and you really need 12?

Eg: http://www.ebay.co.uk/itm/New-DC-12V-24 ... 4af1781e38 Allows up to 5 Amps. 5Volts.

Or more reliable 12 Volts at up to 10A. http://www.ebay.co.uk/itm/DC-DC-Voltage ... 2c6579ddcc

[ex-Gooserider]

Depending on the device, you might also be able to wire it to run directly off of 24V. It will get much hotter and faster, but if it is thermostatically controlled then you might still be able to use it if you turn the setting way down.... (experimentation is indicated!)

Also, it is worth repeating the caution you hopefully are already familiar with, about the EXTREME care needed with any sort of heating device that is in close contact with a person that has a disability... It is very easy to cause severe burn damage at relatively low temperatures if the person can't move off the heat source easily, especially if one has no or limited ability to sense temperature.... There is a real reason that nearly all sorts of heating pads, electric blankets and so on have warnings on them prohibiting use with any person that has a disability that limits either their sensitivity or ability to move away.... Whatever kind of setup you use (especially if experimenting with the 24V I mentioned above) be really sure to have a lot of temperature sensing and safety cutoffs - Burned buns are bad enough in a bakery, you don't want them on your daughter......

ex-Gooserider

[LROBBINS]

The DC-DC converter linked by John:
http://www.ebay.co.uk/itm/DC-DC-Voltage%20...%202c6579ddcc
is a well-made device, but it is NOT well-protected from shorts or reverse voltage (sad experience speaks). I suggest adding fuses on both input and output, and in both + and - leads.
Ciao,
Lenny

[Burgerman]

Also when no device is connected, they draw just 5 to 6mA which is very little from the chair. So can be left connected indefinitely to the battery in a powerchair that is used regularly.

6mA would take 166 hours to take just 1Ah from your typical 70Ah wheelchair battery. Or over 1.3 years to send it flat... If you have not recharged your battery before then its dead for good anyway.

[garriew]

Hey, I built a few of these USB phone chargers and in about 10-15 minutes the USB end is hot to the touch. What could cause this?

[Burgerman]

They are dropping 24v to 5v and its not 100% efficient.

[garriew]

They are dropping 24v to 5v and its not 100% efficient.

So its normal?

[Burgerman]

yes

[garriew]

As always, thanks!

[garriew]

Would this work better if I 3d printed a case?

http://www.ebay.com/itm/5V-USB-DC-7V-24 ... 1777588641

[Burgerman]

Should work much the same. But probably get less warm as its good for 3A.

[ex-Gooserider]

Hey, I built a few of these USB phone chargers and in about 10-15 minutes the USB end is hot to the touch. What could cause this?

As BM said, the DC-DC isn't 100% efficient, and the 'inefficiency' is released as heat... The design needs to get rid of that heat some how, or you will eventually reach the smoke and flame point... If you read the fine print on a lot of the E-bay / China DC-DC units (or look up the datasheet on the chip they use) you will see a note that 'additional cooling' is needed if you are drawing more than a small amount of current....

If you have wrapped up the device, it may be getting quite warm inside, and the USB connector is the only heat radiator. If it gets 'hot to the touch' but not 'burn when touched' and the temperature is stable it should be OK, though I'd look at whether there is an easy way to add more cooling. (i.e. heat-sinks, metal enclosures, etc...)

That said, the unit should NOT get hot if you aren't actually using it for power - the amount of power consumed by the input side of the unit when there is no load connected is negligible, so it should NOT get hot if you don't have anything plugged into it - if it is, you need to start looking for problems.

ex-Gooserider

[garriew]

Hey, I built a few of these USB phone chargers and in about 10-15 minutes the USB end is hot to the touch. What could cause this?

If you have wrapped up the device, it may be getting quite warm inside, and the USB connector is the only heat radiator. If it gets 'hot to the touch' but not 'burn when touched' and the temperature is stable it should be OK, though I'd look at whether there is an easy way to add more cooling. (i.e. heat-sinks, metal enclosures, etc...)

That said, the unit should NOT get hot if you aren't actually using it for power - the amount of power consumed by the input side of the unit when there is no load connected is negligible, so it should NOT get hot if you don't have anything plugged into it - if it is, you need to start looking for problems.

ex-Gooserider

I did take the side metal pieces off and then wrapped it w/ electrical tape to cover the holes.

Its only hot when something is plugged it.

[c500user]

If anyone is looking for a USB charge port, I found 2 that are cheap and easy to use on a w/chair.

The first one is a little 4 x 2.5 x 1.5 plastic box. The cables are hardwired. Output is a 2.00 meter cable terminated with a micro USB connector. The input is a 95 cm cable that you can terminate with an XLR connector. No mA specs given, but should be enough to charge your phone.

hardwired 24v - 5v usb.jpg (10.65 KiB) Viewed 7533 times

I have seen it on a popular Dutch site (similar to ebay) for € 3.50.
http://www.marktplaats.nl/a/auto-divers ... e=lr&pos=3

The second is a 2100mA charger that is intented to permanently mounted. Slightly more expensive (€ 6.99).

usb 24V 5V charger.jpg (9.84 KiB) Viewed 7533 times

http://www.marktplaats.nl/a/caravans-en ... =lr&pos=12

These and other options should be easy to find cheaply on ebay-like websites or at a electornics surplus store. The above examples came were listed under car and camper parts.

[snaker]

I tried several cables like c500user's first pic. They worked but I cannot know their quality and cannot trust them. Eventually I chose the one like below. So I can fit any genuine, high quality cigar charger that I trust.
viewtopic.php?f=2&t=1781&start=60#p65440

[ex-Gooserider]

The problem is that every added plug or connector adds potential problems like bad connections, added resistance, etc...

In addition, my experience is very much that 'High Quality' and 'cigar lighter plug' are mutually exclusive terms - I have never encountered a lighter plug that was other than a total piece of junk (which is not to say that whatever the plug is powering might not be OK once powered with a better connector...

Keep in mind that the lighter socket was never intended to be used as a power plug - it was intended to provide short term power to cigar lighters that automatically unplugged themselves as soon as they got hot... However for many years (and still is to some extent, legacy standards suck) it was the only convenient power outlet in most car dashboards so manufacturers keep making kludgey plugs to fit....

Far better to fit a pair of small (15/30/45A) size Anderson's and run off those, as it is a plug that is designed for power applications, not to mention being a lot smaller and neater.

ex-Gooserider