rodcastler_two Posted May 24 Share Posted May 24 (edited) This is an old technique, many of you are probably using dual voltage switching power supplies for your drives. But I was thinking of the least invasive way of converting a 1050 or an XF-551 to DC and came up with a step-by-step guide. I hope it helps those of you who are not easily finding AC power supplies... Thoughts and ideas are welcome. Link to the instructions Edited May 24 by rodcastler_two 3 1 Quote Link to comment Share on other sites More sharing options...
macsonny Posted May 24 Share Posted May 24 3 hours ago, rodcastler_two said: This is an old technique, many of you are probably using dual voltage switching power supplies for your drives. But I was thinking of the least invasive way of converting a 1050 or an XF-551 to DC and came up with a step-by-step guide. I hope it helps those of you who are not easily finding AC power supplies... Thoughts and ideas are welcome. Link to the instructions This is awesome. Thanks for sharing/ Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted May 24 Share Posted May 24 7 hours ago, rodcastler_two said: Thoughts and ideas are welcome. Nice, so simple too, I would think if possible a 15VDC supply would be best, then there would be no need to adjust the speed (diagnostics disk speed check doesn't work on US Doubler, and maybe Happy). Can't remember if Happy has it's own speed check ? Quote Link to comment Share on other sites More sharing options...
Peri Noid Posted May 24 Share Posted May 24 (edited) 9 hours ago, rodcastler_two said: Thoughts and ideas are welcome. My thought is... a 7812 cannot provide 12V output when powered with a 12V PSU due to internal drop, giving less than 11V. Yes, you may try and compensate the motor speed at 12V as you mentioned but it is not meant to work under such conditions and may not be that stable. So you'd better use something just a bit more powerfull like 15V. And it's not that healthy for a 7805, although it can withstand even 20V (a lot of heat to deal with). But otherwise - yep, it works. I wouldn't risk my drives, though. Edited May 24 by Peri Noid Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted May 24 Share Posted May 24 I've seen this mod and similar and usually the switching power supply is 2.5 amp with the 12v portion adjusted or tweaked slightly upward to around 14.x V (or the upper limit of some of the power supply) the 7805's input limit is well within the ranges I've seen. The other thing I've seen is a barrel adapter plug is in the jack and locked in place with hot melt or other removable adhesive. The adapter is a different size than the AC supply only allowing the DC adapter to be inserted. They appear and it is consistent with the 14.6 v needed to keep most 12 volt regulators actually regulating ant the 5V regulator appears happy with that as well. Other takes on this have the wire going in the drive cases openings to an internal jack with some having 12v/5v fed directly those instances (the supply does both). Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted May 24 Share Posted May 24 (edited) Taking a look at the datasheets, most older 05 and 12 regulators can handle higher than most folks would expect input voltages, and they both like the input above the desired output voltage so they actually are regulating with the input 2.6~2.8 above being the norm. Oddly some newer 05,12 replacements do not appear as robust, and the dc to dc buck type converters are a crap shoot not only for that but noise issues as well. Edited May 24 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
rodcastler_two Posted May 24 Author Share Posted May 24 (edited) 5 hours ago, Peri Noid said: My thought is... a 7812 cannot provide 12V output when powered with a 12V PSU due to internal drop, giving less than 11V. Yes, you may try and compensate the motor speed at 12V as you mentioned but it is not meant to work under such conditions and may not be that stable. So you'd better use something just a bit more powerfull like 15V. And it's not that healthy for a 7805, although it can withstand even 20V (a lot of heat to deal with). But otherwise - yep, it works. I wouldn't risk my drives, though. You are right. However, the oscilloscope shows it to be very stable, mainly because of the multiple capacitors that remain in place. I've never experienced an issue with any of my 1050's nor the XF's in years with this mod. You can always hook the 12v to the output of the regulator instead if you prefer to address that particular concern. The only reason I decided to go this route is to retain the 12v regulator as an extra layer of thermal overload protection, reverse polarity protection and such (although not really needed imho). I also think that the 5v reg will easily take 15v, especially now that the 12v reg has to dissipate less power, hence lower temp operation. Edited May 24 by rodcastler_two typo Quote Link to comment Share on other sites More sharing options...
rodcastler_two Posted May 24 Author Share Posted May 24 (edited) 1 hour ago, _The Doctor__ said: I've seen this mod and similar and usually the switching power supply is 2.5 amp with the 12v portion adjusted or tweaked slightly upward to around 14.x V (or the upper limit of some of the power supply) the 7805's input limit is well within the ranges I've seen. The other thing I've seen is a barrel adapter plug is in the jack and locked in place with hot melt or other removable adhesive. The adapter is a different size than the AC supply only allowing the DC adapter to be inserted. They appear and it is consistent with the 14.6 v needed to keep most 12 volt regulators actually regulating ant the 5V regulator appears happy with that as well. Other takes on this have the wire going in the drive cases openings to an internal jack with some having 12v/5v fed directly those instances (the supply does both). There are two aspects I wanted to keep with this tutorial to maintain it as simple as possible: 1) Use 12v, single voltage power supply, mostly because they are everywhere these days, super easy to find. 2) Keep the original barrel connector for minimal cosmetic disruption and also to keep the front panel power switch working without modding anything else. The barrel connector is also quite common in 12v power supplies. 3) You can easily just swap the 12v power supply with a 15v one with this very same mod and expect zero issues (and probably even better results, only slightly warmer operation). I just happen to find the 12v ones more commonplace. Edited May 24 by rodcastler_two Quote Link to comment Share on other sites More sharing options...
ojanhk Posted May 24 Share Posted May 24 Very nice mod. I will definitely try it on a 1050, but I’m tempted to go a bit further and replace the barrel jack with a USB-C PD trigger providing 15v. I have a few ordered, I will try that when it arrives, a 1050 powered via USB-C can be convenient too. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted May 24 Share Posted May 24 While not a fan of most USB power supplies and their noise/failure modes, the USB C jack does fit in some pre-existing holes/slits etc. Quote Link to comment Share on other sites More sharing options...
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