## Secondary Analysis

## Contents

The Thermaltake Smart 730 W 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 four PFR40L60CT Schottky rectifiers (40 A, 20 A per internal diode at 120° C, 0.60 V maximum voltage drop). This gives us a maximum theoretical current of 114 A or 1,371 W for the +12 V output.

The +5 V output uses two SBR30A40CT Schottky rectifiers (30 A, 15 A per internal diode at 110° C, 0.50 V maximum voltage drop). This gives us a maximum theoretical current of 43 A or 214 W for the +5 V output.

The +3.3 V output uses another two SBR30A40CT Schottky rectifiers. This gives us a maximum theoretical current of 43 A or 141 W for the +3.3 V output.

**Figure 14:** The +12 V, +5 V, and +3.3 V rectifiers

This power supply uses a PS223 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), over current (OCP), and over temperature (OTP) protections. This chip offers two +12 V channels, but the manufacturer decided to use only one of them to make this unit have a single +12 V rail.

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

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