Evidious Posted August 25, 2020 Share Posted August 25, 2020 (edited) Is it a good idea or bad idea to replace the 12v and 5v regulators with more efficient Switching regulators? I was wonder if anyone had any thought on this Edited August 25, 2020 by Evidious Quote Link to comment Share on other sites More sharing options...
+mytek Posted August 25, 2020 Share Posted August 25, 2020 I use them in my 1088XLD and they work great without any need for a heatsinks, and also result in less demand from the 9VAC power adapter, as well as way less heat being generated within the case. 2 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 25, 2020 Share Posted August 25, 2020 they work fine, ive done a few now and as Mytek said, no heat! ? Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted August 25, 2020 Share Posted August 25, 2020 Only potential downside is a slightly noisier DC output due to the high frequency switching and limited filter caps, which has been debated as to any potential downside in reliability, but many have done it, and will reduce draw on the PSU by about 40% and no heat output.... 1 Quote Link to comment Share on other sites More sharing options...
blacka013 Posted August 25, 2020 Share Posted August 25, 2020 Hi All, where can you get these please? Regards Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 25, 2020 Share Posted August 25, 2020 2 hours ago, blacka013 said: Hi All, where can you get these please? Regards Tracopower is a good make: 5v: https://www.ebay.co.uk/itm/TRACOPOWER-TSR-1-2450-CONVERTER-DC-DC-1-Output-5-W-5-V-1-A-Fixed/171119461528?epid=149085216&hash=item27d783c498:g:XP4AAOSwgQ9ViYN9 12v: https://www.ebay.co.uk/itm/TRACOPOWER-TSR-1-24120-CONVERTER-DC-DC-24V-12V-1A-SIP/171948241143?epid=149091254&hash=item2808e9f0f7:g:vCkAAOxyXzxTIip~ you can also get cheaper ones from china if you like 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted August 25, 2020 Share Posted August 25, 2020 9 hours ago, Nezgar said: Only potential downside is a slightly noisier DC output due to the high frequency switching and limited filter caps, which has been debated as to any potential downside in reliability, but many have done it, and will reduce draw on the PSU by about 40% and no heat output.... Yes this can indeed be an issue where audio and video are concerned, and does require additional filtering which was done on the 1088XLD. However neither audio or video noise would be a concern for a disk drive, so it should be safe to go this route. 5 hours ago, blacka013 said: where can you get these please? These are what I used for the 1088XLD. 5V: TPSM84205EAB 12V: TPSM84212EAB And might be a little cheaper then the Tracopower devices depending upon where you purchase them. 1 Quote Link to comment Share on other sites More sharing options...
cwilbar Posted August 25, 2020 Share Posted August 25, 2020 What additional filtering would be needed ? with the rapid switching, I wouldn't think it would need a large cap.... Anyone ever use these in a 400/800 ? Any issues with noise ? Quote Link to comment Share on other sites More sharing options...
+mytek Posted August 26, 2020 Share Posted August 26, 2020 7 hours ago, cwilbar said: What additional filtering would be needed ? with the rapid switching, I wouldn't think it would need a large cap.... None would be needed for the 1050 application, which is what this topic is about. Quote Link to comment Share on other sites More sharing options...
cwilbar Posted August 26, 2020 Share Posted August 26, 2020 y, I got that.... was just curious, that if noise was an issue in a 1050 (which it is not), what sort of filtering would be required which then led into my curiosity of these had ever been used in the Atari computers with on-board regulators.... Quote Link to comment Share on other sites More sharing options...
+mytek Posted August 26, 2020 Share Posted August 26, 2020 1 hour ago, cwilbar said: y, I got that.... was just curious, that if noise was an issue in a 1050 (which it is not), what sort of filtering would be required which then led into my curiosity of these had ever been used in the Atari computers with on-board regulators.... I've never tried that, but there might be enough filtering via the ferrite beads and the capacitors to be ok. If not the first indication usually is a high pitched whine in the audio when you crank up the volume and listen to the background without anything else playing. Next indication of a problem would be herringbone patterns in the video. Here's the filter circuit I used in the XLD to eliminate these issues. 1 Quote Link to comment Share on other sites More sharing options...
Evidious Posted August 26, 2020 Author Share Posted August 26, 2020 Thanks for the feedback everyone Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted August 26, 2020 Share Posted August 26, 2020 6 hours ago, mytek said: Here's the filter circuit I used in the XLD to eliminate these issues. Bear in mind, the filter circuit needed will depend on the frequency the regulator is running at, the ones I've looked at are running at 400KHz , not sure if that's a standard or every manufacturer chooses their own frequency. Quote Link to comment Share on other sites More sharing options...
cwilbar Posted August 27, 2020 Share Posted August 27, 2020 On 8/25/2020 at 11:40 PM, mytek said: I've never tried that, but there might be enough filtering via the ferrite beads and the capacitors to be ok. If not the first indication usually is a high pitched whine in the audio when you crank up the volume and listen to the background without anything else playing. Next indication of a problem would be herringbone patterns in the video. Here's the filter circuit I used in the XLD to eliminate these issues. Is the filtering on the post regulator 5V more complex than the 12V due to more current, different switching frequencies, ??? The 12V post regulator is much simpler with no inductors too. I'm pretty good in the digital realm, and I'm learning more of the analog realm, but this is well outside of my familiarity ? Thanks for sharing the schematic. Quote Link to comment Share on other sites More sharing options...
+mytek Posted August 27, 2020 Share Posted August 27, 2020 17 minutes ago, cwilbar said: Is the filtering on the post regulator 5V more complex than the 12V due to more current, different switching frequencies, ??? The 12V post regulator is much simpler with no inductors too. I'm pretty good in the digital realm, and I'm learning more of the analog realm, but this is well outside of my familiarity ? Thanks for sharing the schematic. The 5 volts is powering the logic, audio, and the video circuits so it needed to be clean. Whereas the 12V was mainly provided for accessories that would likely have their own on board down regulation plus additional filtering. The only on board use for the 12V was to drive the precision 10V zener regulated power supply for the GTIA color adjust circuit. Quote Link to comment Share on other sites More sharing options...
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