Other topologies requires higher and negative

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Unformatted text preview:   –  –  –  Requires reversal of current to pull switching node “up” Requires critical conduction mode Gives variable switching frequency Can be applied to other topologies Requires higher (and negative) currents •  Active clamp circuit –  LC tank controlled by aux switch in series with main switch –  Requires higher currents and voltages Power Factor Notebook Computers Workstations Game Consoles Small­Scale Servers Thin Clients Handhelds, PDAs, and Smartphones Energy Star Regulations 3) Energy Efficiency and Power Management Criteria: Computers must meet the requirements below to qualify as ENERGY STAR. The Version 5.0 effective date is covered in Section 5 of this specification. (A) Power Supply Efficiency Requirements - Requirements are applicable to all product categories covered by the ENERGY STAR Computer Specification: Computers Using an Internal Power Supply: 85% minimum efficiency at 50% of rated output and 82% minimum efficiency at 20% and 100% of rated output, with Power Factor > 0.9 at 100% of rated output. Computers Using an External Power Supply: External Power Supplies sold with ENERGY STAR computers must be ENERGY STAR qualified or meet the no­load and active mode efficiency levels provided in the ENERGY STAR Program Requirements for Single Voltage External Ac­Ac and Ac­Dc Power Supplies, Version 2.0. The ENERGY STAR specification and qualified product list can be found at Note: This performance requirement also applies to multiple voltage output external power supplies as tested in accordance to the Internal Power Supply test method referenced in Section 4, below. Power Factor >= 0.9 at 100% rated output (B) Efficiency and Performance Requirements: 1) Desktop, Integrated Desktop, and Notebook Levels: Desktop Categories for TEC Criteria: For the purposes of determining TEC levels, desktops and integrated desktops must qualify under Categories A, B, C, or D as defined below: Category A: All desktop computers that do not meet the definition of Category B, Category C, or Category D below will be considered under Category A for ENERGY STAR qualification. IEC/EN61000-3-2 d dh ( s ) = vd ( s ) = dh ( s ) h d L s2 LC + s R + hDh i2 Definition s2 + hDh ihVd i LC hDh i2 1 s RC + LC Real P ower PF = Apparent P ower P PF = p P 2 + Q2 1 I1,rms PF = p = 2 Irms 1 + T HD 1 Apparent Power = Vrms x Irms Power Factor Correction •  Correct power factor by regulating input current ...
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This document was uploaded on 04/07/2014.

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