My overly complex setup

I thought it might give some of you a laugh to show you my current extremely convoluted setup. On the top of this standard office document rack you can see my Sky ER115 Router which has DHCP etc.. turned off, effectively turning it into a wireless access point, behind that is a gigabit switch. Next level down is one of those very cheap unlocked OpenReach ADSL/VDSL modems from eBay which is acting as a modem bridge. Next level is a HP Thin Client PC with OpenWRT installed doing all the routing work. The lower level is a USB3.0 HDD connected to the thin client and used for NAS. On the side is a zip tied 120mm computer fan connected to a 5V supply. This still makes the fan spin, but it's slow enough to be totally silent and provides enough air flow to keep the devices from overheating.

The thin client has two ethernet ports, one is the built in gigabit port and the other is a USB2.0 to ethernet adapter. The adapter is connected to LAN1 of the OpenReach modem directly and is used as the modem bridge to the thin client's WAN interface. All other ethernet ports, the LAN2 of the OpenReach (config interface), Sky Router and the thin client's built in gigabit port all go to the switch.

This setup provides me with a good and powerful routing engine that I can install a bunch of stuff on without worrying about RAM or Storage (The thin client has plenty of both) I have the full adblocking lists, recursive DNS, OpenVPN, Tor, Transmission and all sorts on it without any issues. It gives me gigabit speed access to the NAS and provides reasonable Wifi as the ER115 isn't all that bad in that department and it is gigabit ethernet to boot giving me good LAN speed access over Wifi, something you just can't get with those dreadful HH5a things.

Last thing still to do is to consolidate the power. Currently this monstrosity uses 6 power bricks which is insane. Since everything bar the switch is 12V I'm wanting to get a big old 12V supply to feed everything and using a 12V to 9V DC-DC converter for the switch. I'll use 12V for the fan, but I'll incorporate a fan controller to slow it down.

Anyway, hope you found that amusing.



-0.5 pts for single point of failure (12vdc switch mode supply) and extra cost (also a dc-dc). Class 2 wall warts last a long time and are reliable.

Bonus points:

If you can get it to work on the new power scheme. Common ground.

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The main reason for wanting to consolidate the power is that I live in an area prone to power outages and I am setting up a 12V solar system. I want to eventually get it all working on that without having to fuss about with an inverter, so I still have net when the lights go out. BUT! There is a spanner in the works unfortunately, the thin client is in fact 19v not 12v and has that stupid centre pin that forms a resistor divider. So now I'm looking at both a buck and boost converter to get everything going from the single supply. Might have to rethink stuff a little.

Power budget

Estimated full load conditions:

5 port switch = 2W
OpenReach ADSL/VDSL = 7W
Sky ER115 Router = 5W
NAS USB 3.0 = 3.5W
12v FAN operated at 5V = 2W
HP Thin Client PC running OpenWRT only = 12W

Total = ~31.5W max (idle wattage might be ~26W)

31.5W x 24H = ~756Wh per day max.

Unsolicited Recommendations:

fusion power source located 93 million miles away-->12v solar-->up convert to 19v-->down convert to 12v

They sell sealed chassis 100W 12v to 19v 5A DC to DC converters on all the major online retailers for ~$20CAD. Sealed is safer.

A 100W converter running at 31.5W is going to be well within its capacity and should run fairly cool. DC to DC converters are typically 95% efficient - so that beats all inverters ~85% efficiency and wall warts ~85% efficiency combined losses of 30%.

You want to upconvert 12v to 19v because when charging your SLA or FLA lead acid batteries the charging voltage will be 13-14.5V which will potentially piss off or destroy some of the 12v devices downstream if they are connected directly to the battery.

Upconvert to 19v for the thin client and then add a down converter 19v to 12v for all the 12v devices. (The down converter might even have 5v-24v input range which means you could use it as a 12v to 12v converter.) Now the system should be immune to slight variations on the battery during charge / discharge. All converters work better with a slight load.

You could operate the 12v supply as a 12v to 12v as well but I would be concerned about charge cycles pissing it off TBH. Avoid adjustable DC to DC units as they are more prone to problems IMO.

Cooling fan running off USB of one of the devices is a nice solution and avoids extra cost. The fan load may piss off some devices so try to keep it below 2.5W or use USB 2/3.0.


It would be up to you to engineer and test to ensure fire safety, personal safety, equipment safety and functionality etc. not me. Fuse everything. Make safety your top priority.

Pro tip:

I put a smoke detector above my solar power charge controller, all the 12v fused automotive power distribution accessories and batteries and chargers for Lipo 18650's power banks, FLA, etc. and I check them regularly. I keep 2.5 US gallons of water right beside it just in case.

I still use a pure sine inverter as it simplifies everything in many ways and is a safe CSA approved way of doing things. Not as efficient - but a good trade off for my set up. I don't run everything off solar 24/7 I just keep it more for power outages / hobby / fun.



Wow, that's a lot of work and info you just freely gave, I appreciate that a lot. I had been mulling over the possibilities and boosting the SLA to 19v then bucking down to 12v and 9v was one of them. After your reply it seems the best choice. I am currently running the HP on a 19.5V supply that has more than enough capacity for all devices (several times more) so the tower's topology can be setup static with that arrangement. I could then manually swap the power input to the tower during a power outage to the boost converter on the SLA. I've already changed the cooling fan to a 12V PWM controller, so I don't need the 5V line anymore.

Again thanks for that, it was very helpful.

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While we are telling jokes, there is a very popular camper-van youtuber and "technical outfitter" who will set up your "digital office" in your camper-van for you as one of his services. Note here that the camper is already equipped with a solar array and a heavy duty lithium battery bank. The outfitter says to you that mobile power is very unreliable and you really must have a UPS, so the outfitter sells and installs in the camper a 12VDC to 120VAC inverter, plus a 120VAC UPS unit and then plugs all the 120VAC to 12VDC power adapters for all your equipment into the UPS unit. That's some snow (I mean "sales") job for you!

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