Kingwin Mach 1 ABT-700MA1S 700 W Power Supply Review

Secondary Analysis

This power supply uses five Schottky rectifiers on its secondary.

The +12 V output is produced by two S30D60C Schottky rectifiers connected in parallel. Each device supports up to 30 A at 80° C (15 A per internal diode). Since this unit is based on the half-bridge topology, to calculate the maximum theoretical current is easy, it is the simple addition of the maximum current each diode can handle, i.e. 60 A or 720 W for the +12 V output. The maximum current this line can really deliver will depend on other components.

The +5 V output is produced by two S40D40C Schottky rectifiers connected in parallel. Each device supports up to 40 A at 100° C (20 A per internal diode). Since this unit is based on the half-bridge topology, to calculate the maximum theoretical current is easy, it is the simple addition of the maximum current each diode can handle, i.e. 80 A or 400 W for the +5 V output. The maximum current this line can really deliver will depend on other components.

The +3.3 V output is produced by one S30D40C Schottky rectifier, which supports up to 30 A at 80° C. Since this unit is based on the half-bridge topology, to calculate the maximum theoretical current is easy, it is the simple addition of the maximum current each diode can handle, i.e. 30 A or 99 W for the +3.3 V output. The maximum current this line can really deliver will depend on other components.

Even though this power supply uses a separated rectifier for the +3.3 V output, it is generated from the same transformer output that feeds the +5 V rail, so the maximum current the +5 V and +3.3 V outputs can deliver together is limited by the transformer.

It is also interesting to see that the +5 V output uses “stronger” rectifiers compared to the +12 V output. This configuration is typically seen on power supplies with older projects, since in the past a typical PC pulled more current from the +5 V outputs than from +12 V outputs. The trend nowadays is the computer pulling a lot more from the +12 V outputs, since the CPU and the video cards are fed with +12 V, and power supplies with updated projects will use “stronger” rectifiers on the +12 V line than the ones used on the +5 V line.

Figure 14: +12 V and +5 V rectifiers.

Figure 15: +3.3 V, +5 V and +12 V rectifiers.

This power supply uses a WT7510 monitoring integrated circuit, which is in charge of the power supply protections. This integrated circuit features ov
er voltage protection (OVP) and under voltage protection (UVP) only.

Figure 16: WT7510 monitoring integrated circuit.

The thermal sensor is attached to the secondary heatsink and you can see it in Figure 14. This sensor is used to control the fan speed according to the power supply internal temperature.

This power supply uses capacitors from CEC on the secondary, a company from Hong Kong.