Akasa Essential Power 350 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of Akasa Essential Power 350 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU6J rectifying bridge, which supports up to 6 A at 100° C if a heatsink is used, which is not the case, or up to 6 A at 45° C, if a heatsink isn’t used. At 115 V this unit would be able to pull up to 690 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 552 W without burning itself out. Of course we are only talking about this component and the real limit will depend on all other components from the power supply.

Figure 9: Rectifying bridge.

This unit is based on the obsolete half-bridge design, using two KSH13009H power NPN transistors on the switching section, each one capable of delivering up to 12 A at 25° C in continuous mode, or up to 24 A at 25° C in pulse mode. Unfortunately the manufacturer does not provide the current limits at 100&de
g; C.

Figure 10: +5VSB switching transistor and main switching transistors.

The switching transistors are controlled by an AZ7500 PWM controller, which is physically located on the secondary from the power supply.

Figure 11: PWM controller.

The two electrolytic capacitors from the voltage doubler are from Fhy and labeled at 85° C.

Now let’s take a look at the secondary of this power supply.