[5V] Power to the People! [Part 2]

This is a three part article

When I was ‘planning’ [using the word in its loosest sense] this assault on electrical health and safety, I came across an old wooden cigar box in the back of a cupboard and thought it would be pretty whacky to use it as the housing for my powerboard. Also, since last I waxed lyrical about matters electrical, I had been at the online ordering again and got myself what was called a ‘low profile’ 6-way fuse holder, as well as a few other wee bits’n’bobs like, fuses, more wire and some blade terminals from 12 Volt Planet.

When the stuff came, I was a bit disappointed [though not totally surprised] to find that, low-profile or not, the fuse holder wouldn’t fit inside the cigar box, even without fuses inserted. So I had to modify my ‘design’ [loosest sense…] to account for this.

Armed with a craft knife and a drill, I cut holes in the lid of the cigar box to inset the USB sockets and to bring the leads through from the voltage converters 12V input side to the fuse box. I then crimped the terminals onto those leads and attached them to the fuse box.

Having to improvise, because the fuses won't fit inside
Having to improvise, because the fuses won't fit inside

Everything got a good going over with the glue gun to hold it in place. Especially the USB sockets, as they haven’t much of a lip on them so looked like they might push through the lid pretty easily.

Incidentally, I made a schoolboy error at this point:

When attaching the 5V output leads from the voltage converters to the USB sockets, I just wired them to the positive and earth terminals and left the two data terminals unconnected. I subsequently found out that my powerbox wouldn’t charge any Apple gadgets, such as our iPhones, or Mazza’s iPad. I later learnt that this is because the USB standard output is 500mA and iGadgets require at least 1A to charge. So, they ask the USB socket if it can supply more than 500mA and, if they don’t get an affirmitive reply, refuse to charge. Apparently all that’s needed is to short the two data wires together, which fools the iGadget into thinking the USB socket is saying *“Yep. you can have 2A, if you want!” *

Needless to say, I didn’t find out this titbit of information until after I’d wired my USB sockets and smothered them in glue!

You can draw 2A if you want –but the USB sockets can't tell you that
You can draw 2A if you want –but the USB sockets can't tell you that

With all the voltage converter outputs soldered in place and their inputs fed through to the fusebox, it was out with a bigger drill bit and I brought the heavier cable that would connect to the battery into the inside of the cigar box. This was a bit of overkill actually. Apart from the thin wire I was using for the components, I only had 30A wire, which was a lot more heavy duty than I needed. But it had to do. At least it was erring on the side of caution, albeit it was a mite unwieldy to work with.

Heavy duty cable for the battery connections
Heavy duty cable for the battery connections

At this point, I realised I could do with some kind of ‘busbar’ to connect all the individual wires to the main feeds from the battery. Not having such a thing handy, I had to make with the ‘improvisation across the nation’ again. I lathered the bared tips of the main feed cables with flux, heated them with a blowtorch and flowed several gallons of solder into each one. The results weren’t that pretty, but it meant I could easily solder the individual outlet leads onto the big fat main leads now, without any hassle.

If I’d framed up the photo below correctly, you’d be able to see all of this blowtorch-led shenanigans taking place. Unfortunately I haven’t so you can’t –but if you imagine the roar of flaming gas, interspersed with the occasional smell of burning flesh and cries of “Ouch! –that fucking hurt!”, you’ll get the basic idea.

Priming the main leads with solder
Priming the main leads with solder

At this point, I retired to the pavilion for the night, to nurse a glass of Rioja and the third-degree burns to my finger tips.

This is a three part article