Cougar CMX 700 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of the Cougar CMX 700 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBJ1506 rectifying bridge, attached to the same heatsink as the active PFC transistors. This component supports up
to 15 A at 100° C, so in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 W without burning itself out. Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.

Figure 10: Rectifying bridge

The active PFC circuit uses three IPP60R190P MOSFETs, each supporting up to 20.2 A at 25° C or 12.8 A at 100° C in continuous  mode (note the difference temperature makes), or 59 A in pulse mode at 25° C. These transistors present a 190 mΩ resistance when turned on, a characteristic called RDS(on). The lower the number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

Figure 11: Active PFC transistors and diode

The electrolytic capacitor that filters the output of the active PFC circuit is Japanese, from Chemi-Con, and labeled at 105° C.

In the switching section, another two IPP60R190P MOSFETs are used. The specifications for these transistors were already discussed above.

Figure 12: One of the switching transistors

The primary is controlled by an FAN4800 active PFC/PWM combo controller.

Figure 13: Active PFC/PWM combo controller

Let’s now take a look at the secondary of this power supply.