One for the electronics bods

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Believe it or not my 7 month-old lab pup has bitten the power supply cable off the power supply for our BT Home Hub 3.0! I've managed to repair it but, as she bit said cable off immediately after the anti-flex grommet on the adaptor, I had to cut said grommet off leaving me with about 10-15mm of cable to play with so it's not as 100% safe as I'd like it.
I want to buy a replacement and being a tightwad I'd rather not pay BT prices, if indeed they seel just the power supply, but it says it's a 'switching' power supply, can anyone explain what this is please?
I've got my eye on a couple of the same model of home hub on the dreaded auction website, which may work out the cheapest way of getting a replacement, but if anyone can explain the 'switching' thing I'd be grateful.

 

[Globalti]

Woah there! We were given a new Home Hub by BT two days ago and I think the adaptor for the old one is lying on a table (they never take away the old faulty HH). You'd be welcome to have it; let me check when I get home. Meanwhile PM your home address and I'll stick it in a jiffy bag tomorrow.

Edit: Got home and checked; it's yours if you want it.

 

[ColinJ]

I started to write an explanation of how switch-mode power supplies work, but decided that you might as well read this article instead!

It's basically a way of making a small, very efficient power supply.

It doesn't really matter what kind of PSU you have as long as the output voltage, current capacity, power connector and polarity are right.

Anyway - it sounds as though Globalti will sort you out!

Speaking of routers and power supplies ... It turns out that the wireless router that I've just scrounged off my sister doesn't boot reliably. Once it is up and running, it is fine, but it can take a lot of faffing about with power-ups/downs/ups and resets to get it going. I've seen that kind of problem a lot when power-on reset circuitry was faulty or absent. (Circuitry to hold chips in reset until the power supply voltage has stabilised. If it isn't done properly, all sorts of problems can result.) For now, I think I'll just leave it powered up. I use it about 15 hours a day anyway so I'll only be wasting 9/24 of the energy it uses!

 

[Globalti]

My colleague and others I know in Nigeria suffer constantly from domestic equipment failing thanks to the constant power cuts and fluctuations. One customer even had a cellphone charger catch fire and burn out his bedroom, which really traumatised his young children. That may just have been down to a cheap Chinese charger bought from a street hawker though.

 

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Thanks very much Globalti, PM sent