Powering 240v USB ports from 12v

G

gregcope

Well-Known Member
Joined
21 Aug 2004
Messages
1,634
Visit site
hi all

Our boat has 240v sockets that are only on when on shore power. We need more USB charge ports. Ergo I am going to swap some of the sockets for those with USB ports.

I also have an idea of wiring in a parallel USB 5v regulator powered off the 12V supply so that the USB ports can be powered up when on the boat supply.

Does anyone see an issue with this? When shore powered the socket regulator will power up the (switched) 12v-5v regulator, but if switched off this should be fine. Any ideas what happens if left switched on?
 
Since the boat will have the 12v system powered up all the time - I assume that the lighting is all 12v - why not simply install 12v driven USB power sockets?
 
Think it has already been said.

Keep the USB sockets powered by shore power.

Add completely separate 12V powered USB sockets.

Tip: put individual switches on them. I installed four off a master switch, but there's always someone wants to charge a phone or tablet, so it often ends up with all four on.
 
So i did think of seperate 12v sockets, but thats allot of drilling.

Replacing the sockets is easier.

There is a 12v master switch on the main panel.
 
Well, I'm sure that it is feasible to do what you originally suggested - but it will involve modifying the 240v USB charging sockets and I'm always a bit leery about mucking about with USB power. It's not that it's dangerous - clearly not since it is just 5v and low current - but the things you plug into it are typically quite high value - upwards of £1000 for a decent smartphone - and not very tolerant of overvoltage supplies!
 
Have installed 5 usb sockets in all cabins for guests and convenience get a good hole cutter and lead the cables back to master panel and use appropriate fuses and wires not a hard job and looks the part
 
I recently swapped a standard 12C socket for a twin USB outlet exactly as per the ebay link above . I was five minute job.
For use with a 24V socket you can get a plug in adapter .
No need to make it more complicated than that?
 
gregcope said:
So i did think of seperate 12v sockets, but thats allot of drilling.

Replacing the sockets is easier.

There is a 12v master switch on the main panel.
Click to expand...

A fault in the socket could allow 240v AC to come into contact with either the 12v positive or negative wires. Depending on how the boat is wired, this could have some very dangerous consequences.

Bad idea IMO.
 
maby said:
Well, I'm sure that it is feasible to do what you originally suggested - but it will involve modifying the 240v USB charging sockets and I'm always a bit leery about mucking about with USB power. It's not that it's dangerous - clearly not since it is just 5v and low current - but the things you plug into it are typically quite high value
Click to expand...

Personally I’d be more concerned at the possibility of sending 240v back into the 12v system and giving someone a shock. Normally the two systems are not allowed to exist within the same enclosures, wiring trunking, etc - obviously an exception has to be made for items like battery chargers and inverters, but those are packaged items generally not opened up and meddled with. In this case what’s proposed is DIY modifying a cheaply-made (because they all are) switch-mode power supply inside a 240v enclosure.

Odds are the result wouldn’t be dangerous, but I’d still be uneasy at the idea, especially given there’s no good reason to be doing it in the first place - he doesn’t even have the 240v USB units yet.

Simply fitting some 12v USB sockets, which will work at all times regardless of switch settings and shore power, is surely the sensible approach.

Pete
 
gregcope said:
So i did think of seperate 12v sockets, but thats allot of drilling.

Replacing the sockets is easier.

There is a 12v master switch on the main panel.
Click to expand...

As Moomba says, it's a doddle with a hole cutter (30mm suits the ones commonly bought off eBay etc. IIRC). I have a "DC Sockets" switch at the chart table plus a fuse for them. What I wished I'd done (and may still do) is put an individual switch next to each one in each cabin.
 
I've seen (on here I think?) people that have modified a double socket mains faceplate with the USB chargers also embedded. If the 2 types of sockets are isolated and mechanically separated, then it'd be fine but not worth the hassle. Although you'd void the CE marking by doing so.

A lot of modern Fairline boats I work on have modular systems so you can choose what goes where. You buy the frame, with the separate components and then assemble with a bezel of your choice.

I also use a lot of Berker sockets on our classic restorations which have a similar idea in that you can combine different elements into a nice, unobtrusive, visually pleasing system.

Depends on the boat I guess, million dollar Nordhavn is going to look a bit funny with those cheap circular things dozed in the woodwork!!! :disgust:
 
Last edited:
maby said:
Well, I'm sure that it is feasible to do what you originally suggested - but it will involve modifying the 240v USB charging sockets and I'm always a bit leery about mucking about with USB power. It's not that it's dangerous - clearly not since it is just 5v and low current - but the things you plug into it are typically quite high value - upwards of £1000 for a decent smartphone - and not very tolerant of overvoltage supplies!
Click to expand...

and yet people buy Chinese chargers and sockets off eBay to save £5 without batting an eyelid :)
 
Last edited:
Cactus Sailing said:
and yet people buy Chinese chargers and sockets off eBay without batting an eyelid :)
Click to expand...

Some do - even me - though my eyelids do bat a bit! In the post you quote, I was really thinking more about the non-standard configuration that the OP was suggesting - effectively taking a stock 13A socket with built-in USB charging and wiring up a 5v supply powered from the boat 12v in parallel.
 
So general consensus seems to be i am insane, but wothlut any reason rather than i might bridge the live 230v and 5v with a mistake. Better safe than sorry is good advice. Thank you.

Presently i have the 230v sockets and have taken the rear cover of one off. The usb regulator is on a board, firmly attached to the guts of the socket. This is probably for physical security as it holds the acutal usb sockets. Access to the usb VCC and GND is easy. I have also run 12v 2.5mm2 cable to both intended locations from the switch panel and wired them to a spare 5A fuse and switch. Cable running seems to be 70% of the work ...

Options are;

1. Insane option
2. Decouple the usb 230v regulator and wire 12v->5v regulator to usb socket
3. Drill lots of holes and fit a 29mm 12v sockets - added advantage of extended the access to the 12v supply for my tools and you can pop out the usb charger (same as an individual switch).
 
gregcope said:
So general consensus seems to be i am insane, but wothlut any reason rather than i might bridge the live 230v and 5v with a mistake. Better safe than sorry is good advice. Thank you.
Click to expand...

Not quite Greg. My concern (and that of others) is that you introduce the possibility that 240v can come into contact with the boats 12v supply, either negative or positive. With the 240v sockets, as supplied, this cannot happen, as there's no 12v connections to the boat.

Presently i have the 230v sockets and have taken the rear cover of one off. The usb regulator is on a board, firmly attached to the guts of the socket. This is probably for physical security as it holds the acutal usb sockets. Access to the usb VCC and GND is easy. I have also run 12v 2.5mm2 cable to both intended locations from the switch panel and wired them to a spare 5A fuse and switch. Cable running seems to be 70% of the work ...

Options are;

1. Insane option
2. Decouple the usb 230v regulator and wire 12v->5v regulator to usb socket
3. Drill lots of holes and fit a 29mm 12v sockets - added advantage of extended the access to the 12v supply for my tools and you can pop out the usb charger (same as an individual switch).
Click to expand...

You could fit 12v cigar lighter style sockets and use USB adapters or you could just fit double USB sockets. If you have a potential use for the 12v sockets, that seems a sensible solution. You don't have to stick with plain round sockets, for instance : https://clearcutconversions.co.uk/product/cbe-12v-single-socket/

You can also design your own, you could have a double socket, where one is the 12v power socket and the other is a double USB socket : https://clearcutconversions.co.uk/p...v-sockets-and-switches/build-your-own-combos/

No connection to the above company, i used them as an example.
 
PaulRainbow said:
Not quite Greg. My concern (and that of others) is that you introduce the possibility that 240v can come into contact with the boats 12v supply, either negative or positive. With the 240v sockets, as supplied, this cannot happen, as there's no 12v connections to the boat.



You could fit 12v cigar lighter style sockets and use USB adapters or you could just fit double USB sockets. If you have a potential use for the 12v sockets, that seems a sensible solution. You don't have to stick with plain round sockets, for instance : https://clearcutconversions.co.uk/product/cbe-12v-single-socket/

You can also design your own, you could have a double socket, where one is the 12v power socket and the other is a double USB socket : https://clearcutconversions.co.uk/p...v-sockets-and-switches/build-your-own-combos/

No connection to the above company, i used them as an example.
Click to expand...

Thanks for the links - not seen clearcutconversions before.
 
You must log in or register to reply here.

Other threads that may be of interest

Baggywrinkle
Test run of the Lithium system that has been sitting in my cellar for most of this year.
Replies
14
Views
545
Baggywrinkle
Baggywrinkle

Share this page

Top