Sunday 2 August 2020

USB Sockets for Bertie: Why? (And Update 2)

Conrad asked: “What do the new USBs allow you to do that you couldn't before?”

The short answer is: “Technically, nothing.”

The longer answer:

When we’re on the road in Bertie, we are usually off-grid, relying on his 12v leisure battery for our power requirements, including charging phones, watches and the like via USB cables.

Bertie came without any USB sockets, but we have managed for 3.5 years*, albeit with a little inconvenience, by using the one 12v socket on his habitation side**, however, that socket is not conveniently sited and requires the use of a USB adaptor. Fitting the new sockets kills two birds with one stone: accessible sockets and no need for multi-way USB adaptors. 

Here are a few photos to illustrate the location of Bertie’s only 12v socket, on which we have relied to date for all of our charging needs:

This is the TV cupboard:
Looking into the cupboard (the TV is on a slide-out arm), at the very back of the cupboard is the 12v socket:


I searched my gallery for a view of Bertie’s lounge as seen from the cab and almost drew a blank. I’ve photos looking forward, but almost none looking back. This one isn't great, but does illustrates the issue with using this socket – it requires the bottom of the cupboard to be left open, which in turn puts it exactly behind one’s head when sitting on the sofa. I can’t tell you how many times head and door have come into sharp contact.
In case you’re wondering, the wifi booster's plugged in in this snap, hence the trailing wire. 

As for progress on the task of adding the new sockets: well, it’s turning out to be a greater learning experience than I’d anticipated, with associated delays!

I’m no stranger to mains power wiring, but I’m a novice on 12v. It was only yesterday, whilst crimping connectors onto wires, that I realised that my wiring diagram, whilst technically correct, wasn’t as simple to implement as I’d thought. Or rather, I’d just not thought enough about it.

“I’ve got a wire going into A, coming back out of A and going to B, coming out of B and going to C.”

It sounds so simple until I got to the point of ‘wire coming back out of B'*** and realised I had no means of achieving that junction. More research has been carried out and more parts have been ordered.

Given that I’m anticipating more 12v wiring tasks in my future, it’s a learning curve I’m happy to be scaling. Hopefully for the next task, it’ll take less time and fewer iterations to get the shopping list spot-on, with fewer delays as a result.

(*And for the preceding 6 years in Colin, who also only had one 12v socket, also in the back of his TV cupboard.
**Bertie also has a 12v socket and a USB point in the cab, but they both run off the engine battery and are only live when the engine is running.
***I think this is a meaningful statement without me wittering on further, but in case anyone’s after more: ‘A’ in this statement is the switch. It has two connection points ‘+ve in' and ‘+ve out’, so that’s no problem. ‘C’ is the second USB socket and again is no problem, as it only requires a to be connected via the two corresponding posts on its rear. ‘B’ is the first USB is where I’d not applied enough thought to the practicalities, in that it requires a +ve feed in from the switch and a - ve in from the Electroblock whilst also needing both a +ve and a - ve going out to the second USB. Research confirmed that shoving two wires into a single crimp is not good practice, so having considered the options to achieve the necessary junction, I’ve got some piggy back spade connectors on their way.)

2 comments:

  1. When I read the opening sentences I assumed you were refering to USB3 which I understand is capable of providing rather more current than 'standard' USB.
    Are your new USB sockets being fed with 12v, with the appropriate electronics to provide 5v? These things are notorious for generating interference on your Long and Meduium Wave radio-type wireless....but you've probably already discovered that!
    There used to be a (very) local distributor who whould have supplied the required bits and pieces at very advantageous prices, but he sold the business in order to spend more time in the hills.
    Anyroadup, keep the commentary coming, I'm interested to see how you get on - I need to do the same with my caravan.

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  2. I've gone for two twin 2.1A USBs (as in 2.1A each port, rather than the versions that advertise themselves as 2.1A but, when you read the spec, actually share that across the two ports when two things are plugged in). We have a 'fast charge' USB3 plug at home, and it does charge the phones impressively fast, but the 2.1A ones are good enough for our needs (and cheaper, and require less hefty wiring, and are within the fuse rating for the spare terminal on our Electroblock!).

    The new sockets are fed with 12v and contain the necessary magic/electronics to reduce that down to 5v - which is effectively the same arrangement as our previous solution of plugging an adapter into the 12v socket.

    That local distributor to whom you refer nearly got a phone call last week not just to talk connectors, but also to express glee that our mid-May chat about tomatoes has produced fruit.

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