Protecting Hardware on Unstable Power Sources?

psuedo_samurai asks: "Later this year, I will be returning for a visit to a small 3rd world country in Africa. I was lucky enough to travel to the country before, and the last time that I went I was able to bring four fully functional computers that I donated to a local high school, to provide a small computer network for teaching purposes. I had loaded Red Hat Linux with Open Office and a multitude of free goodies onto the systems and everything was working well. The equipment I brought back with me survived for about 12 months, but eventually fell victim to power surges, brownouts, blackouts, and so forth. On my return, I will be better prepared and am planning on setting up 8 computers, this time around. However, I am still stuck on how to best provide either a battery backup (aside from lugging UPS's along with me) with automatic shutdown and/or AVR on the cheap. Does anyone have any good references, experience, or suggestions on how to over come the challenge of running a computer network in a country where the power fluctuates wildly and multiple outages in week are not unusual occurrences?"

Comments

419?

[tepples]

I will be returning for a visit to a small 3rd world country in Africa.

I hope this doesn't have anything to do with an advance fee scam someone sent to your e-mail, does it?

Inverter + charger

[wowbagger]

What you need is known as an off-line UPS, which is nothing more than a battery charger, a battery, and an inverter.

The charger charges the battery, the inverter runs from the battery - if the line voltage spikes, the battery charger takes the hit. If the line voltage sags, the inverter draws power from the battery until power is restored.

You can take along just the inverter if you can count upon getting batteries and chargers for them at your location.

The charger MUST be able to put out more current than the inverter will draw - so for a 400W computer system your charger will need to be able to put out about 40 amps at 12VDC.

The other advantage to this approach is the ability to run off a battery string charged by photovoltaic panels.

Lastly, if you can find somebody with the skill, you can get a replacement power supply for the computer that will take 12VDC to make the voltages for the computer (usually 5VDC, 12VDC, and 3.3VDC) - this will eliminate the inverter (at the downside of using a non-standard power supply for the computers.)