using shelly 2.5 to control pc hdd

  • Hello. I was wondering if Shelly 2.5 could be used in a computer to switch both 12v and 5v for HDD. This setup would require reversed polarity as official wiring diagram (common ground, not positive) and use of external DC-DC step up bulk converter. Question is, would this setup work?

  • Hello, this is not possible. With DC supply, reversing L and N is not possible.

    But you would switch only one supply rail, right? The other one generated by a DCDC converter. Why not using a Shelly 1?

  • I was initially thinking of switching both +5V and +12V rails. I later realized that even reversing polarity would not work because HDD's bolts are grounded.

    Anyway, Shelly 1 can be run with 12V and It could be possible to run/shutdown HDD with switching just one rail (12V for example). But I still want to measure running time and power consumption and just to make sure nothing gets damaged I want to switch both rails.

    Shelly 1PM is probably way to go. I will add a DC-DC converter that will make 24V out of 12V. Then I will be switching both rails with a standard 2pole relay. Sounds complicated, but I guess this is the only way to go.

  • Good question, let me explain. I have two disks in a computer, one is main a second is a backup. There is no reason for backup disk to be running all the time. I do my backups only once a few days. Second reason is that only a shutdown disk is truly protected from malware like ransomware. After few years when the main disk is expected to be in trouble of any kind (hardware malfunction, malware, data loss by accident,...) the backup disk will be in better shape overall with less running hours and less spin ups. No brute force turning off is intended.