Universal Power Supply
|Universal Power Supply|
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A Universal Power Supply forms the backbone of an off-grid electrical system.
This is a combination inverter, converter, pulse-width modulation current controller, and high frequency power supply for applications from off-grid power, charge controllers, to power supplies for welders, induction furnaces, and plasma cutters.
A large range of power electronic devices is desirable within the infrastructure of communities. Having an individual power supply for each is redundant and expensive. A modular UPS construction kit is desirable as an analogue to the 'industrial-strength Lego' that we have already demonstrated for heavy mechanical hardware infrastructures.
Rectification is the conversion of AC to DC. A universal power supply would require one or two rectifying stages: one at the AC input to provide DC for the voltage converter, and another if the voltage converter is a proper Active PFC converter, which produces PWM shaped output.
Rectifiers can be either passive schottky diode bridges, or active (IC-controlled) MOSFET H-bridges. Passive ones are cheaper, and ultimately more efficient for very high currents, while active ones are superior for low-medium-and-maybe-high currents yet more expensive. This design choice affects price, producability and simplicity.
In either case a rectifier stage requires power packaged components and a heat sink. The size of the heat sink is a function of the current, which is higher at low voltages for a given output power. Questions for the specification is how much power the device should be able to deliver from a 12V source (first rectifier in the case of voltage up-conversion) and to a load at 12V DC output (second rectifier if present).
 Voltage Converters
An inverter is an electrical device that converts DC voltage from batteries to AC voltage for off-shelf electrical tools and appliances.
Off-the-shelf inverters have about a 2 year lifetime, and 5-10 year lifetime for higher quality models. Lifetime design inverters with plug-in replacement components are required for sustainable communities which use battery storage as a component of their electricity infrastructure. One of the few other feasible, non-battery, non-fuel energy storage may be via heat storage coupled to thermoelectric generators, or possibly thermal storage via phase-change salts and heat engines.
 Product Ecology
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