5 ms·

Some chargers don't do 12V or 15V, but will do 5V, 9V and 20V. This depends a lot on the total wattage. Lower watts, like 20W or 30W can or can not do 15/20V, b

by gbraad 3y ago

Some chargers don't do 12V or 15V, but will do 5V, 9V and 20V. This depends a lot on the total wattage. Lower watts, like 20W or 30W can or can not do 15/20V, but 12V@1.5A (18W) and 12V@2.5A (30W). Usually the >65W will do most of them, plus PPS. Always check specs. And what is the input voltage this powerplug expects; 15V or 20V? > Utilizing any 12V-capable If so, this is usually at a VERY low wattage. they usually go to a max of 2.5 or 3A max at 12V. I would expect it would use 20V and step-down as 20V is more generally available at a high Amperage. (Note: 3A is the max possible for cables without an E-marker, os if often regarded as a ceiling). This would have made the device much bigger (and more versatile. a clear trade-off). Actually, I am more concerned about -12V, ... at 0.1A. That seems rather low. Also, the 12V rail itself is only 1.0A. The original supply did 12V@2A and -12V@0.5A if not mistaken, and so does the C64psu.com. Overall, rather low Amp values. This might affect 'stability' if your machine is expanded (although it claims: "of even the most expanded configurations"). Curious if they can share some details. I have a BlizzardPPC in my A1200. > allows users to tap into a vast array of affordable and readily available “power bricks” if DC5521 at >12V to 20V is possible, that would be great, as this allows you to use a Lenovo or generic laptop brick, or a USB-C trigger cable. Perhaps something I should make ...

laubzega 3y ago
Principal designer of PowerShark here. Original PS spec from Commodore defined 5V/3A, 12V/0.5A and -12V/0.1A as max. load (http://www.kaiiv.de/servicemanuals/A500_Power_Supply_Specification.pdf http://www.kaiiv.de/servicemanuals/A500_Power_Supply_Specifi... page 3) It was in later models bumped up to 5V/4.5A and 12V/1A, with -12V unchanged. In actual use, a "wedge" Amiga consumes just below 30mA from -12V line. Visit our page, there is now a detailed FAQ and a list of various USB-C power supplies we tested with PowerShark.
p1mrx 3y ago
One would hope that they based their power limits on real-world measurements. Maybe the original power supply was oversized to avoid efficiency loss near 100% load, or because precise overcurrent protection wasn't available?
- gbraad 3y ago
  I'd rather have headroom than running in an overcurrent situation. I hope than can provide more details about the capability and what they tested. I moved away from the stock supply many moons ago as it wasnt as stable anymore, plus of powering the accelerator board, plus the CD-drive and harddisk
bluescrn 3y ago
The A1200 at least will actually function without -12V, but the audio will be bad. I had crackly audio problems. I swapped the A1200 motherboard (a few years back when they were still fairly cheap on eBay), and still had the same audio problem. Only then did I investigate+repair the PSU issue. Recently built a replacement Amiga PSU from a MeanWell PT-65B board in a 3D printed case. This USB-C option would have been neater and easier (so long as it puts out enough power for a PiStorm as well as the Amiga)
- gbraad 3y ago
  Pistorm would be 5V. But yeah, perhaps an idea to move away to this instead... Most likely less power hungry. Haven't had the time yet... The place I am in is hard to get shipped in reliably.
- snvzz 3y ago
  >Only then did I investigate+repair the PSU issue. This is why you always check the voltages first.
bogantech 3y ago
In these machines +/-12V is only used for Audio op-amps, RS232 Line drivers and the floppy motor. everything else is running on the 5V rail.
- gbraad 3y ago
  That is not completely true. The opamps for sure, but the 12V rail is also used for external devices, eg harddisk, cd drive, expansion cards, etc. Too low current on the -12V rail can cause crackling sound. I use my A1200 machines mostly for this, although more using AHI than before.
  - bogantech 3y ago
    > the 12V rail is also used for external devices, eg harddisk, cd drive, expansion cards, etc External drives should have their own power supply and indeed the A590, A570, GVP drives etc all do. The A500/A2000 Technical Reference (page 227) shows that the 12V current limit on the expansion connector is 50mA The A600/1200 don't even have the expansion connector Page 5 of the TRM specs the -12V supply at 100mA > Too low current on the -12V rail can cause crackling sound. Maybe if the current is zero TRM: https://archive.org/details/CommodoreAmigaA500A2000TechnicalReferenceManual https://archive.org/details/CommodoreAmigaA500A2000Technical...
    - gbraad 3y ago
      I thought the trapdoor (cpu slot) also exposed 12V, but just checked and I was wrong. Thanks for clarifying that the 12V rail might be sufficient.

by gbraad 3y ago

laubzega 3y ago

Principal designer of PowerShark here. Original PS spec from Commodore defined 5V/3A, 12V/0.5A and -12V/0.1A as max. load (http://www.kaiiv.de/servicemanuals/A500_Power_Supply_Specification.pdf http://www.kaiiv.de/servicemanuals/A500_Power_Supply_Specifi... page 3) It was in later models bumped up to 5V/4.5A and 12V/1A, with -12V unchanged. In actual use, a "wedge" Amiga consumes just below 30mA from -12V line. Visit our page, there is now a detailed FAQ and a list of various USB-C power supplies we tested with PowerShark.

p1mrx 3y ago

One would hope that they based their power limits on real-world measurements. Maybe the original power supply was oversized to avoid efficiency loss near 100% load, or because precise overcurrent protection wasn't available?

gbraad 3y ago
I'd rather have headroom than running in an overcurrent situation. I hope than can provide more details about the capability and what they tested. I moved away from the stock supply many moons ago as it wasnt as stable anymore, plus of powering the accelerator board, plus the CD-drive and harddisk

bluescrn 3y ago

The A1200 at least will actually function without -12V, but the audio will be bad. I had crackly audio problems. I swapped the A1200 motherboard (a few years back when they were still fairly cheap on eBay), and still had the same audio problem. Only then did I investigate+repair the PSU issue. Recently built a replacement Amiga PSU from a MeanWell PT-65B board in a 3D printed case. This USB-C option would have been neater and easier (so long as it puts out enough power for a PiStorm as well as the Amiga)

gbraad 3y ago
Pistorm would be 5V. But yeah, perhaps an idea to move away to this instead... Most likely less power hungry. Haven't had the time yet... The place I am in is hard to get shipped in reliably.
snvzz 3y ago
>Only then did I investigate+repair the PSU issue. This is why you always check the voltages first.

bogantech 3y ago

In these machines +/-12V is only used for Audio op-amps, RS232 Line drivers and the floppy motor. everything else is running on the 5V rail.

gbraad 3y ago
That is not completely true. The opamps for sure, but the 12V rail is also used for external devices, eg harddisk, cd drive, expansion cards, etc. Too low current on the -12V rail can cause crackling sound. I use my A1200 machines mostly for this, although more using AHI than before.
- bogantech 3y ago
  > the 12V rail is also used for external devices, eg harddisk, cd drive, expansion cards, etc External drives should have their own power supply and indeed the A590, A570, GVP drives etc all do. The A500/A2000 Technical Reference (page 227) shows that the 12V current limit on the expansion connector is 50mA The A600/1200 don't even have the expansion connector Page 5 of the TRM specs the -12V supply at 100mA > Too low current on the -12V rail can cause crackling sound. Maybe if the current is zero TRM: https://archive.org/details/CommodoreAmigaA500A2000TechnicalReferenceManual https://archive.org/details/CommodoreAmigaA500A2000Technical...
  - gbraad 3y ago
    I thought the trapdoor (cpu slot) also exposed 12V, but just checked and I was wrong. Thanks for clarifying that the 12V rail might be sufficient.