Auto-poweroff for an external USB hard drive

Posted on Thursday, March 21st, 2013 in project logs by DP


Hlipka has written an article about his auto-power-off project:

I have an external hard drive connected to our satellite receiver for quite some time (to have it work as a PVR). But for some reason the disk won’t power down even with the receiver switched off (I verified – the disk itself is configured properly). So yesterday I went ahead and added small circuit to the enclosure switching it off when the USB master (the receiver) is turned off. The circuit I used looks like this.

Via the forum.

This entry was posted on Thursday, March 21st, 2013 at 9:00 pm and is filed under project logs. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

3 Responses to “Auto-poweroff for an external USB hard drive”

  1. CanaDave says:

    We have an external hard disk attached to a satellite receiver for Bell ExpressVu service…they intend for it not to turn off and say that if your enclosure turns it off it will cause problems. The receiver stays active and receiving codes and stuff even when it’s turned off..if you unplug your drive from the receiver, you have to re-format the disk and lose whatever you saved.

    Now, if you come up with a hack for the receiver that lets you save your un-encrypted stuff to your computer, let us know :)

  2. hli says:

    When the receiver wants to write to the disk even when it has been (formally) powered off, you cannot switch the disk off. My receiver really goes into sleep, not only into some kind of doze-mode. But you can check whether it changes the Vusb line – maybe you can use that information to power down the disk…

    As for accessing the recorded stuff: my receiver saves it as HD-Transport stream, so I can just plug the disk into my computer and copy it over :)

  3. CanaDave says:

    Sounds like your receiver is better than ours :)

Leave a Reply

Notify me of followup comments via e-mail. You can also subscribe without commenting.

Recent Comments

  • Drone: So these go for around $330 USD and NO published calibration procedure online or otherwise? Given what's inside - I don't think I'll be considering...
  • Pekka Akselin: This is ridiculous!? :-) We are back at 256(!) byte EPROMs that needed multiple, a handful, of voltages to run! :-(
  • KH: Let's try a back-of-envelope calc balancing energies. From MCP1700 datasheet, there are graphs for a 200mA load step. Estimate the energy shortfall as 12uJ. Say...
  • Daniel: It's been a week and my comment is still awaiting moderation. Apparently the CIA doesn't want their involvement known?
  • KH: Agree, so okay, I guess he must have learned from somewhere. 100nF and 1000uF is so far apart, that was jarring; it's more magic incantation...