Is there a method to avoid a power supply and utilize direct DC power instead?
Is there a method to avoid a power supply and utilize direct DC power instead?
Is there a method to avoid using a power supply and instead use direct DC power? I believe a power supply converts AC input to DC, while the computer or motherboard relies on DC. In an off-grid scenario with solar power feeding a battery bank, solar inverters lose significant efficiency when converting DC to AC for the supply and then again when converting AC back to DC. This means that multiple conversions can reduce overall efficiency. Some people propose using a DC-to-DC converter to control specific voltage levels for devices. Have anyone experienced this approach before? Has it been discussed in the context of computers, servers, or Bitcoin mining?
There are already established methods for handling direct lower voltage solar power and converting it to DC for charging a 12V system. You could simply extract the voltage for 12V and then utilize high-efficiency DC-DC converters, using components similar to those found in PC power supplies.
There are also numerous PCs with DC input capabilities available. For running devices like laptops, a boost converter from around 12V to 19-20V—potentially delivering about 5A—is sufficient. You’ll likely find many options on Amazon, though you’d need to adapt the connector for your specific laptop.
If your requirements are higher, such as between 24 or 48V, a high-efficiency DC-DC converter would be appropriate. For access to high-voltage DC, you have several ready-to-use options, allowing you to skip the AC side and connect directly to main capacitors. This approach may require some adjustments to POST circuits for optimal performance, but it’s a more advanced and potentially safer method. For direct operation, you’d need around 200V DC for a 110V AC source and approximately 400V for a standard 240V supply.
If you’re interested, consider Vicor modular bench supplies for various DC-to-DC converters. These are not inexpensive.
For a laptop, it's certain.
The division of voltages occurs on the laptop motherboard.
A desktop, with 20/24 pin input, then also the CPU/GPU/SATA connections – a different setup.
There are ATX 12VO models available and motherboards built for direct DC input, though that isn't typically what I'm after. A converter that changes low voltage DC to higher voltage DC could enable such setups if they weren't limited to 12V input, but I'm aware there are systems that do exist. However, they usually don't match the full desktop performance levels.
If you require 12V at around 100Amps for your 5090 system, it would be quite costly.
Another approach involves using high voltage power supplies. You could connect a PSU directly to the main capacitors and, with some modifications, achieve a very clean DC output. This method is risky and not recommended for safety reasons.
There are ready-to-use solutions for off-grid AC power, which might be a more practical choice, even if they are less efficient.
Here is a module that connects to an AC-powered backplane:
https://www.artisantg.com/TestMeasu...Gu...oFUt2NCyfY&gQT=1
It outputs 100W at 12V from a 300V DC input. You can connect multiple units in parallel to reach several hundred watts, though smaller systems only accept up to 8 units. These are highly efficient but expensive options.
If you prefer not to convert DC back to AC at around 70% efficiency or lower, you'll need to consider more advanced equipment.
I spent 30 seconds searching the internet and came up with this 12V DC input 1000W ATX PSU.
https://www.powerstream.com/DC-PC-12V-1000.htm
This is obviously an old design because it's plastered in Molex connectors and only two SATA but it proves such DC input designs exist.
No, you cannot "Bypass a power supply" entirely unless your solar power system magically charges a 12V battery, a 5V battery and a 3.3V battery, or something else that's compatible with your motherboard and GPU. You need an ATX PSU to generate 12V, 5V and 3.3V from the solar battery.
It doesn't matter if the ATX PSU runs on 100V to 240V AC 50/60Hz, or 12V DC, or something else. It could run on any AC or DC voltage there's a (niche) market for. It wouldn't surprise me if there are 48V DC input ATX PSUs.
It may take a bit of searching, but all I did was enter "ATX PSU with DC input for solar system" into a web browser. Simple.