1. I have a USB charger that I got with my first mobile phone in 2004.
Will it work with PowerShark? If not, what will?
As much as we appreciate retro-tech, in this case you need something
decidedly more contemporary. PowerShark requires any USB-C PD
supply that can output 12V
at min. 1.35A
(heavily expanded Amigas
will need more, see question 7). There is no point in looking for
the supply's PD spec version or Profile number, because they do not
map 1:1 with voltages actually available. Just check if the required
voltage is listed in the datasheet and that's it.
If you are not on a tight budget, just buy a 12V/3A power supply and
be done. They are often just a few bucks more.
Also, here is a spreadsheet with more information about USB-C PD power
supplies we have tested.
2. But what if I plug a non-compatible charger into a PowerShark? Will
there be fire, loud noises, things melting? More importantly, will I
damage my PowerShark?
Fortunately none of the above. After power-on, PowerShark's LED will
turn on RED, no output will be produced, and that's it. So it makes
sense to first try various chargers you have at home, if the LED turns
on GREEN, the 12V output is there.
3. What about multi-port chargers?
Many of them perform "power rebalancing" when a new device is being
(un)plugged, briefly stopping power delivery to all ports. That
obviously won't make your Amiga very happy, because it does not have
an internal battery to sustain it throughout these gaps. So either get
a single-port power supply, or remember not to play with other ports
when you're using your Amiga.
Additionally, keep in mind that many multi-port chargers reduce power
available in individual ports, if more than one are in use.
4. How long can I work on a battery?
Forever, if the battery is continuously being replenished. :)
Otherwise, it depends on the size of the battery and the configuration
of your Amiga. On a machine with no power-hungry expansions you will
get nearly 2:30h from a 10,000 mAh battery, or nearly 8h from a 30,000
mAh one. Before getting a USB-C powerbank, do check a) if it provides
12 V, b) how many amps it pushes at this voltage (see question 1 for
details). Most of 10,000 mAh powerbanks max out at 1.5A, which won't
be sufficient for very expanded configurations (yet still fine for
5. PowerShark is so small that I can't bring myself to believe it can
deliver enough power for my setup. Can it handle anything more than a
Yes it can. The last forty years of semiconductor development did not
focus only on CPU speeds and memory sizes. We now have components
which can do power conversion with efficiency unimaginable to '80s
engineers, and in equally unimaginable form factors. Substantial part
of the PowerShark design process was component selection and testing,
optimizing for stability, size and efficiency. Don't ask how many
prototypes we built on the way.
6. Uh, how many prototypes did you build on the way?
13, starting with this monstrosity:
7. My Amiga has every expansion ever manufactured plugged into it. Will it work?
In our experience, people frequently have a somewhat exaggerated idea
of their Amiga's power consumption, because most power supplies
currently used (including Commodore's and contemporary aftermarket
ones) have relatively low efficiency. When the power consumption is
then measured at the mains socket, it is often way off from what is
really used by the Amiga. Large part of it goes into heating the power
supply (and sometimes the cable).
But there are obviously limits. So far we have not seen an Amiga that
failed to stably work with a 12V/3A power supply, but it does not mean
there isn't a guy somewhere who managed to assemble a configuration
that makes lights darken when powered on. Generally though, you should
avoid pumping much more power than the Amiga connector - and circuit
board's tracks - were designed to carry, and for a very heavily
expanded setups, supply power through some additional connection. As we
receive more information from our users, we will publish detailed
information about the limits and consumption of various setups, but so
far our testers exercised configurations with 68030/40/60 accelerators,
Vampires, RaspberryPi (3 and 4), ACAs, graphics/networking cards,
flicker-fixers, Goteks, external drives, etc., and the largest
observed draw from the 12V line was below 2.2A.
8. Does USB-C cable matter?
It does in the sense that some cables are more efficient than others,
so if you are aiming for maximum efficiency, you should get a cable
with less resistance, especially if your Amiga is very souped up. As is
usual, it is difficult to rely on branding and ads, because some
claimed to be great - aren't. Here is probably the best site to get
more information about specific cables:
(look for PDF link). Rule of thumb is to get a 5A cable, because it
should have a thicker conductor. Out of bazillion cables we
used/tested, INIU (6.6ft) 100W PD 5A
uni USB Type C 100W Fast Charging Nylon Braided Cable (5A 20V)
worked best, but there are probably equally good ones available in your
market (or on your shelf).
BTW, retrousbpower.com is an Amazon Affiliate and may receive commision
from products sold through links on this page.
9. How about GaN?
In practice it matters less than the cable, but GaN power supplies are
usually somewhat smaller. Go for it if you want the latest and
greatest, but you will save more energy by getting a better cable.
10. What protection is present in PowerShark?
There are three types of failures that are guarded against:
- Faulty USB-C power supply resulting in under- or
overvoltage on 12V input. Unlikely, but since we do not
control what power supply is attached, it makes sense
to monitor what it delivers. If it goes out of
acceptable range, PowerShark stops power delivery and
makes its LED red.
- Failure of voltage converter circuit inside PowerShark
resulting in an overvoltage. Even more unlikely, but
since it is well known that impossible things do happen
occasionally, and nobody wants to be responsible for
frying an Amiga, we check for that and we cut off power
if voltage exceeds 6V even for a few microseconds.
- Temporary undervoltage caused by PowerShark failing to
handle a large load transient. A regular power supply
will pretend that nothing happened, while the connected
Amiga hangs or does something otherwise undesired.
Since the user obviously has no idea what just took
place, (s)he may suspect a software problem or be
generally confused. PowerShark is not like that - it
will enter the lockout mode, stopping all current flow
and turning its LED red, so you can immediately see
that it was an inadequate power that led to failure.
All this in addition to
overvoltage, overcurrent, and undervoltage
protection already present in the voltage converter chips.
Finally, PowerShark protects your Amiga by preventing quick powercycles. If either you, an overloaded power supply or some other protection circuit turns off power, the device will only restart after a few seconds - even if the ON/OFF switch is in the ON position. The exact delay depends on the power consumption of your computer, but it will be a few seconds.
11. Can you explain how powershark conserves power and thus extends the existence of life on planet Earth?
Most devices using USB-C power turn on at least partially as soon as
the power plug is inserted. They negotiate voltage and current, and
then remain on standby, waiting for further user actions. Even if your
laptop battery is full and it's hibernated (regular standby needs some
power for DRAM refresh and a few other things), the USB-C charger needs
to constantly work and provide current.
PowerShark is not like that - when its switch is in the "OFF" position,
the device remains totally invisible to the power supply, which
believes nothing is connected, and so it remains dormant. Only after
PowerShark is turned on, the power supply realizes that the USB-C plug
has been inserted, and initiates powering on its voltage converter,
starts delivering 5V, and then negotiates the voltage.
12. What's the deal with 12 V being not always available in USB-C power supplies?
It's an exemplary case of "design by committee", where said committee
defined in spec v1 what voltages HAVE TO be available in chargers of
particular wattage. Later they thought some more, and for v2 they
figured it would be a-ok to replace 12V with 15V. After all we're only
talking about MANDATORY voltages, and you can keep others, too, so no
problem here. There are no hardware changes needed, either. Just add a
few lines of code to your chip's firmware and you are done.
Naturally, for manufacturers it was easier/faster/safer/cheaper to just
search-and-replace "12" to "15" in their code, rather than implement
new features, so this is what happened in at least some cases. Most
manufacturers came to their senses very quickly, but there are
outliers, too. Chargers that are delivered with laptops or VR headsets
usually are missing 12V output. Some (major) brands needed time to
realize that getting your chargers blacklisted because of unsuitability
for some applications enabled by V1 of the standard is bad for
13. I heard somewhere that magnetic connectors for USB-C should be avoided.
We heard that too. Two reasons are usually cited:
- Disturbances in the data lines leading to slower data
transmission. Very true, but PowerShark only
communicates over CC lines, where the PD protocol
operates at just 300 kHz, and so is not affected by
some minor noise. Worst case, an unreadable packet
(wrong CRC) will be retransmitted. Again, speed is not
very important here, given how little data is
- Static electricity. PowerShark has ESD diodes on all lines
that lead to the USB-C connector, in addition to ESD
protection in the chips that connect there.
But clearly, a magnetic connector is another device in the power chain.
This device by itself may be working very well, or not at all. So take
a look at its current rating and reviews at the minimum.
And one more thing. Used with a laptop, if you trip over the cable and
disconnect it, the laptop will continue working thanks to its battery.
In contrast, your Amiga will shut down immediately. While that sounds
bad, the alternative is a potential damage to USB-C plugs or sockets or
your life and limb, if you manage to trip over in especially