On demand backup drive.

I have to make my backing up more frequent. 

Right now I use a double dock, with a 5 1/4" drive.  I bought one whose
advertising said it turned off when it wasn't getting input, but
afterwards, when I tried to get the software the ad said was needed,
someone there admitted there was no software and it didnt' do it!!!**

Is there a 5 1/4" dock that will turn off when not in use. 


I have the impression that those 2 1/2" backup drives do indeed turn off
when I'm not backing up.  Do they?  All of them?  Any that you
recommend?  Any you recommend against? 



(I wanted the HDD image to be made to a 5 1/4 so if there were a
problem, I could just swap HDD's.  That would work, right?  But most of
my backups are just data files (not part of a disk image). and I can't
stand to have the drive spinning 24/7 when I only back up for 10 minutes
once a day or less. And I can't reach the switch without standing up and
going around the desk.) 



WRT my email backups, if there is a crash (and I just had several) the
program rebuilds the table of contents but does a half-baked job, and if
I back that up, I no longer have a backup of a good toc.  Some software
keeps more than one generation of backup.   Any recommendations? 


**This is the second time advertising lied to me. Back during dial-up
and call waiting, a modem claimed to let me know when someone was
calling me, but after I bought it, it didn't work either and someone on
the phone admitted it didn't work. 

TIA