English Amiga Board - View Single Post - Amiga 500 PSU ref P.312503-03 singapore (Heavy PSU)

e5frog · 07 October 2020, 17:28

Not sure about the policy here, continue a subject in old thread or start a new one on the same subject?
I chose to continue.

Had used an Amiga-PSU for other stuff, just sold my A600 and with it the "everyday" switched A600 PSU. When now restoring the heavy Amiga 500 312503-03 I thought I'd swap caps.

Not sure if the late 80's Marcon and Necon brands are still any good but for such an important detail it's worth spending a few dollars to keep the other end safe (which is a lot more $), it's been over 32 years...
Marcon seems to be OK in general, Necon... don't know.

The six original caps in this one, all of them Marcon, 105 degree except C10 which is Necon.
I have added diameter and raster (distance between pins) values to the list as it's a very important detail when you try and fit them. Modern capacitors are generally smaller but the proper raster measurement is nice if you don't want to bend pins here and there.

It's my understanding the caps should have ESR less than the old ones, preferably as low as possible. Ripple current tolerance is another detail, highest possible.
Can't really find any proper specs on these - so, guesswork regarding the ripple? I guess I'll get the best and hope it's enough.

C1: 40V, 2200µF, D 16mm, raster 7mm, ESR <0.06 Ohm, V-L: 1.9%
C2: 40V, 2200µF, D 16mm, raster 7mm, ESR <0.07 Ohm, V-L: 1.6%
C5: 16V, 470µF, D 10mm, raster 5mm, ESR <0.24 Ohm, V-L: 4.6%
C9: 25V, 330µF, D 10mm, raster 5mm, ESR <0.21 Ohm, V-L: 3.9%
C10: 40V, 330µF, D 13mm, raster 5mm, ESR <0.32 Ohm, V-L: 1.5%
C11: 50V, 10µF, D 5.5mm, raster 2.5mm, ESR <4.3 Ohm, V-L: 8.4%

So... _seems_ pretty much OK, all of them measure above printed capacitance except C5 and C9, which also have the highest V-Loss. However, all are within the usual tolerance of 20% regarding capacitance. Measurements has not been made at the voltage they are used so... measurements like this doesn't give all the information. Getting in there with a 'scope and checking the details could be done - but... naah.

Important is also to buy from a reputable source, perhaps not get those cheap Panasonic caps from a Chinese seller at 1/10th of the price for the same thing at DigiKey - then they are likely fake or actually called "Pansaonic", "Ponasonic", "Penisonic"... or something like that...
;-)

07 October 2020, 17:28	#16
e5frog The Headstrong Join Date: May 2010 Location: Älvängen / Sweden Age: 49 Posts: 273	Not sure about the policy here, continue a subject in old thread or start a new one on the same subject? I chose to continue. Had used an Amiga-PSU for other stuff, just sold my A600 and with it the "everyday" switched A600 PSU. When now restoring the heavy Amiga 500 312503-03 I thought I'd swap caps. Not sure if the late 80's Marcon and Necon brands are still any good but for such an important detail it's worth spending a few dollars to keep the other end safe (which is a lot more $), it's been over 32 years... Marcon seems to be OK in general, Necon... don't know. The six original caps in this one, all of them Marcon, 105 degree except C10 which is Necon. I have added diameter and raster (distance between pins) values to the list as it's a very important detail when you try and fit them. Modern capacitors are generally smaller but the proper raster measurement is nice if you don't want to bend pins here and there. It's my understanding the caps should have ESR less than the old ones, preferably as low as possible. Ripple current tolerance is another detail, highest possible. Can't really find any proper specs on these - so, guesswork regarding the ripple? I guess I'll get the best and hope it's enough. C1: 40V, 2200µF, D 16mm, raster 7mm, ESR <0.06 Ohm, V-L: 1.9% C2: 40V, 2200µF, D 16mm, raster 7mm, ESR <0.07 Ohm, V-L: 1.6% C5: 16V, 470µF, D 10mm, raster 5mm, ESR <0.24 Ohm, V-L: 4.6% C9: 25V, 330µF, D 10mm, raster 5mm, ESR <0.21 Ohm, V-L: 3.9% C10: 40V, 330µF, D 13mm, raster 5mm, ESR <0.32 Ohm, V-L: 1.5% C11: 50V, 10µF, D 5.5mm, raster 2.5mm, ESR <4.3 Ohm, V-L: 8.4% So... _seems_ pretty much OK, all of them measure above printed capacitance except C5 and C9, which also have the highest V-Loss. However, all are within the usual tolerance of 20% regarding capacitance. Measurements has not been made at the voltage they are used so... measurements like this doesn't give all the information. Getting in there with a 'scope and checking the details could be done - but... naah. Important is also to buy from a reputable source, perhaps not get those cheap Panasonic caps from a Chinese seller at 1/10th of the price for the same thing at DigiKey - then they are likely fake or actually called "Pansaonic", "Ponasonic", "Penisonic"... or something like that... ;-)