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Secondary Analysis

The Antec VP450 uses a regular design in its secondary, with Schottky rectifiers.

The maximum theoretical current each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.

The +12 V output uses two MBR20100CT Schottky rectifiers (20 A, 10 A per internal diode at 120° C, 0.95 V maximum voltage drop). This gives us a maximum theoretical current of 29 A or 343 W for the +12 V output.

The +5 V output uses one HBR3045 Schottky rectifier (30 A, 15 A per internal diode at 150° C, 0.7 V maximum voltage drop). This gives us a maximum theoretical current of 21 A or 107 W for the +5 V output.

The +3.3 V output uses another HBR3045 Schottky rectifier. This gives us a maximum theoretical current of 21 A or 71 W for the +3.3 V output.

Antec VP450 power supplyFigure 13: The +3.3 V, +12 V, and +5 V rectifiers

This power supply uses a WT7527 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. This chip offers two +12 V channels, correctly matching the number of +12 V rails advertised by the manufacturer.

Antec VP450 power supplyFigure 14: Monitoring circuit

The electrolytic capacitors that filter the outputs are from CapXon and Teapo, and labeled at 105° C, as usual.

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Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.