Huntkey Balance King 5000 500 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of Huntkey Balance King 5000. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one T15XB80 rectifying bridge, which supports up to 15 A at 100° C if a heatsink is used – which is the case – but only 3.2 A at 25° C if a heatsink isn’t used. Here we saw a great advantage of Balance King 5000 over other units from Huntkey: most power supplies from this manufacturer we’ve reviewed use the same bridge, but without having a heatsink attached (including Balance King 4500). On Balance King 5000 the manufacturer fixed this problem. Curiously the models from this brand that we’ve tested and didn’t explode – Jumper 550 and Titan 650 W – are the only ones that have this component
attached to a heatsink… Hum…

At 115 V this unit would be able to pull up to 1,725 W from the 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 component and the real limit will depend on all other components from the power supply.

Figure 9: Rectifying bridge.

The two electrolytic capacitors of the voltage doubler circuit are from CapXon and rated at 85° C.

As mentioned, Balance King 5000 has an active PFC circuit. This circuit uses two 2SK2837 power MOSFETs, each one providing a maximum current of 20 A at 25° C in continuous mode, or up to 80 A at 25° C in pulse mode (unfortunately the manufacturer doesn’t say the maximum current at 100° C). These transistors present a typical resistance of 210 mΩ, which is a good number. The lower this number is, the better, meaning higher efficiency.

The active PFC circuit is controlled by an ICE2PCS01 PFC controller.

Figure 10: PFC controller.

Balance King 5000 uses two 2SC3320 power NPN transistors on its switching section using the obsolete half-bridge design, each one supporting up to 15 A at 25° C (unfortunately the manufacturer from these transistors do not say how much they can deliver at higher temperatures). These are the same transistors used on Balance King 4500, Green Star 550 W, V-Power 550 W and Titan 650 W (Rocketfish 700 W) from Huntkey. These transistors are more “powerful” than the ones used on the 350 W, 400 W and 450 W versions from Green Star power supplies.

Figure 11: Switching transistors, active PFC diode and one of the active PFC transistors.

The primary is controlled by an AZ7500 PWM controller, which is physically installed on the secondary.

Figure 12: PWM controller.

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