DC Interconnect Scheme for ATX Power Supply Units
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Solution Overview
Problem
Current power supply units (PSUs) for computers suffer from inefficiencies due to high voltage drops in AC interconnects, primarily caused by insufficient cable diameter and high contact resistance in connectors, leading to power losses and reduced efficiency ratings.
Innovation Solution
The implementation of alternative AC interconnect schemes using lower gauge wire and connectors with reduced contact resistance, such as IEC 60309 plugs, terminal blocks, circular and rectangular connectors, and direct connections, which replace or complement standard IEC 60320 connectors to minimize voltage drops and heat dissipation, thereby enhancing overall efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If IEC 60320 connectors are used for AC power input, then the PSU can supply high power (1000-1200 watts), but voltage drops approach 1 volt at 11.5 amps resulting in power loss of approximately 11.5 watts
Solution Approach 1:
The patent changes the electrical parameters of the interconnect system by replacing IEC 60320 connectors with IEC 60309 connectors that have lower contact resistance, and by using lower gauge wire (12-14 gauge instead of higher gauge), thereby reducing voltage drop and power loss while maintaining high power supply capacity
Solution Approach 2:
The patent segments the AC interconnect path into distinct components (connector, cable, wiring) and optimizes each segment independently - using IEC 60309 connectors with specified contact resistance, lower gauge cable with specified resistance per foot, and direct wiring methods to minimize total voltage drop across the complete interconnect path
2Device complexity
If IEC 60320 power cords with insufficient cable diameter are used, then the connector size and complexity are reduced, but voltage drops increase due to high resistance
Solution Approach 1:
The patent changes the physical parameter of the cable by specifying lower gauge wire (12-14 gauge) with lower resistance per foot, directly reducing the voltage drop across the cable while maintaining manageable connector complexity through the use of IEC 60309 connectors
3Device complexity
If IEC 60320 connectors with high contact resistance are used, then the connector design is simplified, but power loss increases due to high contact resistance between inlet and power cord
Solution Approach 1:
The patent changes the electrical parameter of the connector by specifying IEC 60309 connectors with maximum contact resistance of 5 milliohms per contact, significantly lower than typical IEC 60320 connectors, thereby reducing power loss at the connector interface while maintaining reasonable design complexity
4Ease of operation
If modular cables with sub-optimal connectors are used for DC output, then cable management and connectivity are improved, but contact resistance and wire series resistance increase causing power losses
Solution Approach 1:
The patent changes the electrical parameters of the DC modular cable system by specifying connectors with maximum contact resistance of 1 milliohm per contact and wire with maximum series resistance of 0.0005 ohms per foot, minimizing power loss while maintaining the ease of operation benefits of modular cable design
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These solutions reduce power losses and increase efficiency by lowering voltage drops and heat dissipation, improving the performance of high-current power supply units compatible with personal computers and workstations.
Implementation Method 1
The voltage drops across the complete interconnect path including the input AC line cord and power inlet connector from the line source to the neutral return can approach 1 volt at 11.5 amps. This results in a power loss of approximately 11.5 watts
Implementation Method 2
Such losses largely originate from two sources: 1.) The voltage drops in the IEC320 power cord are a result of the use of cable with insufficient diameter (the AWG rating and resistance is too high); 2.) The voltage drops in the IEC320 inlet originate from high contact resistance between the inlet and the mating end of the power cord
Data Source
AI summary
An ATX compatible power supply unit having at least one DC power outlet and at least one DC power cable, the DC power outlet configured to support nominal contact resistances of less than 2.5 milliohms per contact or the DC power cable configured to support series resistances of less than 4 milliohms per linear foot of individual conductor is disclosed.