DIY power panel - In progress

[Vox45]

After consulting with savvy DIY users in this forum (this thread and this one) I finally took the plunge.

I will be building a power panel. My first project was to build a power box but I got inspired by this

I wanted the flexibility of being able to use any battery I wanted without being dependant of a fix battery in a box. This way I can use a small and light battery for short sessions, bring a big one for star parties, or even borrow one on location when I travel.

The power panel is a good choice for my needs and it can also be mounted with velcro on the mount itself as it is very light. This way there are only 2 cables coming from the mount (1) the power cable to the battery (2) the USB cable to my laptop.

Material I bought for this project:

1x switch 12 V/DC 12 V/DC 25 A      2.90 €
5x DC-DC 3A Buck Converter Adjustable Step-Down Power Supply     4.35 €
50x female crimp     4.86 €
1x fuse holder 12V 4x     5.68 €

2x 1.5mm solid wire 10m  8.80€
2x WAGO 8 poles (distribution)     7.10 €
2x Neutrik Speakon male     7.49 €
2x Neutrik Speakon female     7.60 €
1x Crimper tool   8.00 €
1x Voltmètre display     8.49 €
2x Cigar lighter sockets    9.89 €
1x Project box TEKO P/4 215 x 132 x 78     12.99 €
1x Set of 3 step cone drill bit    13.99 €
1x Charger H-Tronic AL 300 Pro     15.58 €
2x CSL - 5m cable USB     19.00 €
1x Velleman soldering station 48W 150 - 450°C     22.90 €
1x HQ BAT-LEAD-12 Batterie (12V 7.2Ah/20hr)      24.89 €
1x StarTech ST4200USBM Hub USB     64.99 €

So that's around 175€ of parts + charger and battery and some tools (crimper and drilling bits) ... note that the powered hub is 1/3 of the price

Some of these will be reused in futur project so the price will go down a lot for version 2.0

[Vox45]

First steps: drilling holes !

The plastic did not crack and it went rather smoothly using a 'hole saw'  but, although it did the job, it was very hard to be precise, one hole is bigger than the other .... I was lucky it doe not show

I bought a 'step cone drill bit' and will be using it for the rest of the holes...

[Vox45]

So that's around 175€ of parts + charger and battery and some tools (crimper and drilling bits) ... note that the powered hub is 1/3 of the price

Let me rephrase that: the total cost of the project is around 175€ and that includes tools/soldering station/powered hub.

The cost of the parts alone is much less (around 75€)

[Alien 13]

Looking good, a soldering station is always handy look forward to completion.

Alan

[Vox45]

Looking good, a soldering station is always handy look forward to completion.

Alan

Thanks to you in part lots of advices you gave me were taken into account and proved to be very valuable

[Vox45]

I just got my new soldering station (a bit cheap but better than what I have) and the drill bit

Project will restart tonight

[Snaxmuppet]

Crickey! What is that? It looks like it could do a lot of damage if put in the wrong kind of place 

Never seen one of those before.

[Lonestar70]

Commonly known as a step drill... great for plastic boxes and for sheet metal and much safer than a standard twist drill, which can easily screw it'self into sheet metal if great care is not taken even when it is specially sharpened specifically for sheet material use.

These don't have a spiral flute so they dont catch you out in that way.

It is advisable though, regardless of which you use, to clamp the workpiece down to prevent any movement.

They come in both Imperial and Metric step diameters with varying numbers of steps.

That particular one goes from 4mm dia to 32mm dia in 2mm steps.

Their only limitation is that the thickness of material being drilled must be no thicker than the individual step height.

Clear skies.

Sandy.

[Vox45]

Crickey! What is that? It looks like it could do a lot of damage if put in the wrong kind of place 

Never seen one of those before.

he he

I've seen some people using this to drill holes in plastic boxes. The nice thing is that you start with a small hole and count the steps until the desired size in mm (inscription on side of the drill bit) perfect hole everytime and no risk of slipping or cracking the box. Some people just put a piece of tape at the desired mark instead of counting (makes more sens to me)

[Snaxmuppet]

Thanks everyone... I have ordered one

[Vox45]

Little update on my progress

My wife and child being gone at Mami's house for 4 days I was able to expand my work area to the whole living room

I Started the wiring and soldering

Wiring:

After a while I realised that the path I took was a dead end, I was using wires that were too short by fear or not having enough before noticing that I'd only use 20% of it (I bought 2 rolls of 5m!!) I decided to strip it all, cut everyting and redo the wiring and connectors properly ! It was much neater the second time around and a good lesson learned for version 2.0

My biggest problem so far is with the stepdown modules. Out of the 5 I received from China, only 2 were working (output above 0v). I read that these cheap convertor sometime just give up and instead of providing the chosen voltage they just let the whole voltage supplied go through (!) Since I wanted to use the step down to 8v for my DSLR I am now a bit concerned ...

Soldering:

Soldering was also a bit of an issue as I anticipated. It went really well for the XLR and Speakon but it was a bit of a mess on the tiny PCB. I managed to do it but it took me some time to understand that the iron was not hot enough. Once I got it properly setup it was way easier, thanks to the 3rd hand, which is a must by the way.

Fuses:

I bought some inline fuses as my fuse boxes were way to big to fit inside the box They really seem nice, on paper at least, as they do not need any connectors or soldering... just put 2 wires and clamp. I'll see if they are as easy to use as they look.

Holes:

Cutting holes is so much easier using the step drill bit. A well spent 13€ !

[Alien 13]

Are you sure that the converters are dead? they will be using multi turn pots so you might have to wind them a long way.

Alan

[Vox45]

Are you sure that the converters are dead? they will be using multi turn pots so you might have to wind them a long way.

Alan

I turned the screw on the pot both ways 10 turns without any changes in the output voltage (0.0v) on the remaining ones I found that 2 turns would start changing the voltage quite fast :/

The thing that worries me the most is the fact that when it fails it outputs the input voltage (12v) which is not good for my DSLR. I do not know if this is the case for all step down converter or only on cheap copies. I would assume that when failling it should output 0v not let 12v go through ... Urban legend or fact, I will research this

[Alien 13]

I turned the screw on the pot both ways 10 turns without any changes in the output voltage (0.0v) on the remaining ones I found that 2 turns would start changing the voltage quite fast :/

The thing that worries me the most is the fact that when it fails it outputs the input voltage (12v) which is not good for my DSLR. I do not know if this is the case for all step down converter or only on cheap copies. I would assume that when failling it should output 0v not let 12v go through ... Urban legend or fact, I will research this

Not good, if they fail that way but you could add a protection with a zener diode (8.2v 2A) and an inline fuse (crowbar circuit) this should prevent any damage to the camera.

I have a battery grip with my camera that can also accept AA cells this outputs around 9.4V with a fresh set of duracells so the camera supply has some headroom, so by setting the voltage at 7.4V the circuit above would blow the fuse if the regulator exceeds 8.2V.

Alan

[cjdawson]

I love the design so far.  I'm doing the v2 of my power box, with built in dew heater.  Hadn't thought about including a way to power my DSLR at the same time.  That and the Step change drill bit.  You learn something every day.

[Vox45]

I love the design so far.  I'm doing the v2 of my power box, with built in dew heater.  Hadn't thought about including a way to power my DSLR at the same time.  That and the Step change drill bit.  You learn something every day.

Made a couple of basic mistakes ... crooked holes, color of the box, size of some components (fuse boxes) but overall that is a good 1st experience. Since I already have all the component and plenty of wire and connectors left, I plan to do a version 2 by just changing the project box but first I'll use it in the field a couple of time as a proof of concept and see what needs to be modified ...

I just go my clip inline fuses and they look good... I just need to cut a wire anywhere and fit the fuse without having to solder anything which is a good thing for me

[cjdawson]

It's definatly worth running with your V1 project for a while before starting work on the V2.  I'd say, have a notepad without and make plenty of notes.  I'd take the time to make three lists.

1. Stuff that works well

2. Problems that you have encountered

3. Ideas for other features.

Keep them all separated, then when you are designing the V2 project, carry over the stuff that works well, try to resolve the problems from that first run, then if there's time/space/money, see if you can include further features.

I've done the same thing with the power project that I'm working on for my scope, and am considering changes that I wouldn't have thought about before.  I'm waiting for some parts to arrive before I can answer some of the questions, which will delay my project, that's not a real problem, as I want it to be right, rather than rushed.

[Vox45]

See Version 2 here :)

 

[kirkster501]

I'm in the middle of building one of these too.  I also treated myself to a Dremel ;-)  Dremel is a mighty useful tool.

[Gina]

I have a cheap Chinese copy of a Dremel but I think I may treat myself to a proper one