Powered USB socket(s) feeded from onboard 24V circuit

[MapisM]

I've got several 24V sockets onboard the DP, which are as useful as a chocolate teapot.
I'm wondering if there are such things as small 24V-5V converters, that I could stick inside the existing plates, replacing the weird 24V sockets with USB modules.
Is anyone aware of such things?
Goes without saying that it should be able to handle an input with a variable voltage range - i.e. anywhere between 24 and 28 or so...
Tx in advance!

 

[Whitelighter]

I have the same - but 12v bticino do a USB plate that will fit but I have no idea if it will step down the voltage. They are quite expensive (like €20 each) so they might have something on board.

 

[noelex]

Several of the marine USB sockets will accept a 24v input.

The new Blue Seas "fast charge" models are expensive, but very efficient.

 

[MapisM]

I have the same - but 12v bticino do a USB plate that will fit but I have no idea if it will step down the voltage. They are quite expensive (like €20 each) so they might have something on board.

J, I'm afraid I've got Vimar stuff onboard, not Bticino.
Anyway, I believe that just about any supplier (be it Bticino, Vimar, Gewiss or whatever) makes some USB modules for their plates nowadays.
Trouble is, they are obviously meant for home usage, so they take 220AC as input.
Sure, I could connect all 220AC sockets to an inverter and then feed these USB modules with AC, but that's sort of silly, when I already have 24V sockets available and unused...
...Hence the question!

 

[MapisM]

The new Blue Seas "fast charge" models are expensive, but very efficient.

You mean this stuff, I suppose?
Mmm... Yeah, the electric specs fits what I have in mind nicely, but aside from being indeed expensive, it's designed for its own panel installation.
To do what I have in mind, I should hide the thing somewhere behind the existing plates, and then connect a couple of short USB cables from those sockets to the USB modules which I was thinking to use to replace the 24V sockets...
Ideally, it would be nice to find just the small electronic board which is surely embedded inside that cylinder, connect it to the 24V in input and to my plate-specific USB modules.
Good suggestion anyway! :encouragement:

 

[petem]

P, can't you just wire a voltage step down behind the socket? Loads on eBay.

Look at this on eBay http://www.ebay.co.uk/itm/281740160175.

 

[MapisM]

In principle, yes, but what I found so far (also in the ad you linked, unless I missed something) is either a 24->12 step down or a 12V->5V, but not a 24->5.
Sure, I could connect 24/12 plus 12/5 in series, but I hoped to find some 24/5 units to keep things simpler and smaller...

 

[petem]

In principle, yes, but what I found so far (also in the ad you linked, unless I missed something) is either a 24->12 step down or a 12V->5V, but not a 24->5.
Sure, I could connect 24/12 plus 12/5 in series, but I hoped to find some 24/5 units to keep things simpler and smaller...

Sorry, you want 5v so these will work:

http://www.ebay.co.uk/itm/DROK-DC-D...457405?hash=item3f82fb75bd:g:p-gAAOSwpXNZeqY0

http://www.ebay.co.uk/itm/DC-24V-36...397668?hash=item4b0c638be4:g:No4AAOSwQaJXSBFr

There's loads on eBay just search for "voltage step down 24v 5v"

 

[noelex]

There are a number of very cheap 24v to 5v converters.

You can wire these to a USB socket, but the trap is a voltage is needed on some of the other pins to tell the device (phone or tablet) that the converter is capable of delivering a high current. This can be done with a resistor bridge, but it gets a bit fiddly. Without this, the converter will only charge many devices very slowly (if at all) even if the converter itself is capable of delivering plenty of current.

There are models which offer the correct voltages on the other pins. Something like this:

http://www.ebay.com/itm/CAR-DC-12V-...r-Step-down-Iphone-IPAD-Charger-/261679188988

Be aware that not all these models are well designed/made. Things like no over temperature shut down can have serious consequences.

 

[MapisM]

Sorry, you want 5v so these will work:
http://www.ebay.co.uk/itm/DROK-DC-D...457405?hash=item3f82fb75bd:g:p-gAAOSwpXNZeqY0
http://www.ebay.co.uk/itm/DC-24V-36...397668?hash=item4b0c638be4:g:No4AAOSwQaJXSBFr
There's loads on eBay just search for "voltage step down 24v 5v"

Doh! Can't even remember what sort of search keys I tried, but never found those thingies, many thanks.
The one in your second link looks perfect, nice and small, and with a very high acceptable range of input voltage.
I'll give it a try! :encouragement:

 

[MapisM]

Be aware that not all these models are well designed/made. Things like no over temperature shut down can have serious consequences.

Very good point, considering also that I would install the things hidden inside the plates, hence normally not visible - till the s...moke hits the fan, that is! :ambivalence:
BUT, is there anything around other than cheap Chinese stuff, these days...?!

 

[noelex]

Very good point, considering also that I would install the things hidden inside the plates, hence normally not visible - till the s...moke hits the fan, that is! :ambivalence:
BUT, is there anything around other than cheap Chinese stuff, these days...?!

The other alternative is mount something like the Blue Seas converter behind the panel. Plug in a USB cable and cut the wires and attach it to what want (or use a USB cable with female socket that can be panel mounted).

This is much more expensive and is probably overkill, but some of these USB devices get very hot and make me a little nervous. Using a proper marine grade device made by a reputable company (like Blue Seas) gives some peace of mind.

With these sort of dilemmas I often think money is better spent making the boat as safe and as well built as possible rather than necessarily spending money on every piece of safety gear that is designed to used after a problem occurs (such as fire and subsequent sinking).

 

[Whitelighter]

In principle, yes, but what I found so far (also in the ad you linked, unless I missed something) is either a 24->12 step down or a 12V->5V, but not a 24->5.
Sure, I could connect 24/12 plus 12/5 in series, but I hoped to find some 24/5 units to keep things simpler and smaller...

So it might work for me?

 

[vas]

P.,

which VIMAR line you've got? I run Idea and there are USB 1U sockets so all cabins have at least one USB thing.
Behind it I originally got some Farnell solid state tiny black things that I wired to the right 2 ports of the USB.

Result was that Samsungs and a few other brands of mobile phones would charge fine. My son's Xperia would also charge, my Zsomething Xperia (top of the range a few yrs ago) wasn't impressed at all. Iphones would sometimes charge.

This winter got fed up and ordered some 2 or 3 A variable output charger boards http://www.ebay.co.uk/itm/5Pcs-DC-D...-2-5V-35V-M-/152180562613?hash=item236eab1ab5 .

With them I can (slowly) charge my new Xperia XPerformance, son's new xperia works, daughter always has samsungs and they work. Even wife's iphone 6S charges. Obviously need a multimeter and turning the bronze screw until you're happy with the voltage before installing!

I'd like to check what noelex says about informing the phone that it's a quick charger, any ideas on pinout and diagrams please?

cheers

V.

 

[snowbird30ds]

A lot of 12-5v converters use a 7805 voltage regulator, these will take up to 35v input, there's just not a big market for for 24-5v so they don't advertise as such.
Check the datasheet and you will probably find one easily.

 

[mcanderson]

How about these - https://www.plastimo.com/en/prise-ubs.html

 

[noelex]

I'd like to check what noelex says about informing the phone that it's a quick charger, any ideas on pinout and diagrams please?

Basically, normally pin 1 and 4 supply the 5v power. Normally pin 2 and 3 are reserved for data.

However when connected to a charger many devices need to know the power the charger can provide. Some USB chargers can only supply 0.5A (or less) while others can supply 2.4A (or more). Many devices use pins 2 and 3 so the device (phone tablet etc) can communicate with the charger and determine the maximum power the charger can supply. Trying to draw 2.4A from a charger only capable of delivering 0.5A could cause problems.

The voltage on pins 2 and 3 tell the device (phone tablet etc) if it is connected to high or low powered charger. If no voltage is present the device will default to a low charge rate, or not charge at all, even if in reality the charger is capable of delivering a high current.

Thus, using a simple 24v to 5v converter may not work even if the device is the correct voltage and can supply plenty of current.

Suplying the correct information on pins 2 and 3 is therefore important. You cannot simply hook up a 24v to 5v converter on the power pins of 1 and 4.

The last time I looked, I think from memory, pin 2 needed to be provided with 2.0 v and pin 4 with 2.75v for the device to accept a fast charge (pin 1 and 4 need 5v), but this standard is constantly changing as higher power chargers are released, so I would encourage a Google search.

In short, a standard 24v to 5v converter will not work for most devices unless you incorporate some additional circuitry to supply the correct voltage to the other pins. Some commercial devices incorporate this into the design, but it is important to buy a device that is labeled something like "suitable for charging iPad" rather than a universal 24v to 5v converter that has been suggested in some posts.

 

[MapisM]

which VIMAR line you've got? I run Idea

Me 2, but I don't think Idea line was already available when your boat was built. Maybe you mentioned it in your rebuild thread and I don't remember, did you replace all that stuff?
Thanks for the additional suggestion anyhow, but how hot does that small board run? The ebay add suggests to add a heat sink...

Though I must say that based on Noelex explanations I'm not so sure anymore that it's a good idea to bother fitting anything at all! :ambivalence:

 

[noelex]

Though I must say that based on Noelex explanations I'm not so sure anymore that it's a good idea to bother fitting anything at all! :ambivalence:

Don't be discouraged. USB chargers are very useful. So many devices are using this standard such as tablets, phones, cameras etc, etc is nice to have lots of charging outlets.

If you wire in commercial USB outlets they will take care of the latest standards for the correct voltage on pins 2 and 3 to match to charge rate.

When buying these try and choose the higher powered models. These will still happily charge lower powered devices.

The best marine sockets offer two outlets both at 2.4A. Slightly older units typically offer one outlet at 2.1A and one at 1A. Cheaper units are one outlet at 2.1A or less.

Typically the latest tablets will accept 2.4A, slightly older 2.1A. Smart phones are usualły 2.1- 1A. Older devices are 1A.

A higher potential charging rate of the better units will do no harm, and helps as the converter will run a bit cooler.

It is only when you making your own USB socket from a simple 5v voltage supply that you need to be concerned about the voltages on pins 2 and 3.

 

[MapisM]

It is only when you making your own USB socket from a simple 5v voltage supply that you need to be concerned about the voltages on pins 2 and 3.

Yup, understood.
Trouble is, that's the only way which allows me to use the existing Vimar plates, replacing the existing 24V socket modules with the USB module of the same line - which would be the "cleaner" installation.
Sure, I could use for instance those "Blue Seas" outlets, sticking them behind the plates and connecting them to the USB modules, but I'm not sure it's worth the hassle and the cost, just for a bit of additional convenience!