(o';'o)
Active member
Hello All,
I am currently looking into designing a drop in replacement power supply for the SE/30 that would fit all of the major versions of stock PSUs. What I have currently found is that there appear to be three major versions: Two from Astec, and one from Sony. I was able to obtain one Astec and one Sony PSU, and JDW was kind enough to ship me the second Astec for me to inspect and get mechanical measurements. My aim to is create a single PCB version that would fit into all of the metal enclosures, would be easy to install (little to no soldering), and would not require a cooling fan.
I have a few questions that I'm looking to get some guidance on:
(Note that I have read through https://68kmla.org/bb/index.php?threads/modern-psu-for-the-se-30.30945/)
1) Is anyone aware of any other versions of power supplies that were used with the SE or SE/30 other than what I have pictured (Two pictures are screenshots from JDWs YouTube video)?
2) What is the necessity for providing separate +12V supplies for the disk and sweep circuits? I have seen some folk say there there is no issue with running them both from a single supply, but others have mentioned that there is potential for display artifacts when the disk drive pulls current. My initial thought, other than the visual artifacts, would be some concern about the sweep flyback circuit causing spikes to be reflected to the disk drive, which could cause errors or disk failure. (I realize this question has been posed in other threads, and that there is an isolation diode between the two, but I don't think I've read anything that was conclusive).
3) Some folks would argue that the stock PSU current capabilities are limited, especially if someone were to install upgrade cards. Does anyone have a measured value for what current rating would be required, given the worst case of upgrades? And would this only apply to the 5V supply, or should the +12V and -12V have increased ampacity? I'm looking for concrete, measured current values.
Many thanks in advance!
-Chris
I am currently looking into designing a drop in replacement power supply for the SE/30 that would fit all of the major versions of stock PSUs. What I have currently found is that there appear to be three major versions: Two from Astec, and one from Sony. I was able to obtain one Astec and one Sony PSU, and JDW was kind enough to ship me the second Astec for me to inspect and get mechanical measurements. My aim to is create a single PCB version that would fit into all of the metal enclosures, would be easy to install (little to no soldering), and would not require a cooling fan.
I have a few questions that I'm looking to get some guidance on:
(Note that I have read through https://68kmla.org/bb/index.php?threads/modern-psu-for-the-se-30.30945/)
1) Is anyone aware of any other versions of power supplies that were used with the SE or SE/30 other than what I have pictured (Two pictures are screenshots from JDWs YouTube video)?
2) What is the necessity for providing separate +12V supplies for the disk and sweep circuits? I have seen some folk say there there is no issue with running them both from a single supply, but others have mentioned that there is potential for display artifacts when the disk drive pulls current. My initial thought, other than the visual artifacts, would be some concern about the sweep flyback circuit causing spikes to be reflected to the disk drive, which could cause errors or disk failure. (I realize this question has been posed in other threads, and that there is an isolation diode between the two, but I don't think I've read anything that was conclusive).
3) Some folks would argue that the stock PSU current capabilities are limited, especially if someone were to install upgrade cards. Does anyone have a measured value for what current rating would be required, given the worst case of upgrades? And would this only apply to the 5V supply, or should the +12V and -12V have increased ampacity? I'm looking for concrete, measured current values.
Many thanks in advance!
-Chris
