Re: [LUG] Hot swapping hard drives

[Robin Cornelius <robin@xxxxxxxxxxxxxxxxxxxxx>]

> best advice possible is don't do it.....
>
> the quickest way to kill IDE drives is to hard switch the power on them,
> this applies also to the non-hot-swap drives when you pull a hot swap one.
>
> I build these sorts of computers all the time, and the ten quid "hot swap"
> caddies are really just removeable caddies, very useful for swapping hard
> drives without having to open a case, they ate NOT hot swap, if you MUST
> hot swap get a separate power rail for the hot swap drive, this basically
> means a separate power supply, doesn't have to be an ATX, and buy a GOOD
> caddy, eg 70 quid's worth.
>
> Not this also applies to proper hot swap scsi, you can't mix them with ide
> on the same PSU unless you want the ide to die young.

If you don't mind some DIY you can protect against these type of problems 
fairly easily, you would need devices like "transorbs" between each power 
rail and the ground(0v) line. What happens is that if you break a "flowing" 
current you can get "fly-back" where you end up with a voltage much bigger 
than you started with the transorbs will clamp any over voltage protecting 
your equipment (they need to be of the correct voltage rating to clamp at the 
correct voltage). these would need to be on the HD side, but both sides 
dosn't hurt. and a liberal scatering of inductors also stops any "rapid" 
current change characteristics.

Of cause these problems technicaly exist on ALL the connectors you are 
breaking (eg ALL 40 pins of IDE and power pins)  but the power supply is 
worse as the flyback effect is related to how much current you are breaking 
and the 12v line is quite heavy.

Totally over the top and unnecessary off-topic information!

Regards

Robin

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