On this page we will take an in-depth look at the primary stage of the Huntkey Jumper 300G Planet3dnow.de Edition. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.
This power supply uses one T10KB80 rectifying bridge, attached to an individual heatsink. We couldn’t find the datasheet for this component, but we can easily assume it is a 10 A part, so in theory, you would be able to pull up to 1,150 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 920 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.
The active PFC circuit uses one SPP20N60C3 MOSFET, which supports up to 20.7 A at 25° C or 13.1 A at 100° C in continuous mode (note the difference temperature makes), or 62.1 A at 25° C in pulse mode. This transistor presents 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.
The active PFC circuit is controlled by a CM6502 chip.
The electrolytic capacitor that filters the output of the active PFC circuit is Japanese, from Rubycon, and labeled at 105° C.
In the switching section, two STF15NM60ND MOSFETs are used. Each transistor supports up to 14 A at 25° C or 9 A at 100° C in continuous mode, or 56 at 25° C in pulse mode, with an RDS(on) of 299 mΩ.
The switching transistors are connected using a design called LLC resonant, controlled by a CM6901 integrated circuit, which operates under PWM (Pulse Width Modulation) mode when the power supply is operating under light load but under FM (Frequency Modulation) mode under other loads. This controller was placed in the secondary section of the power supply, on the same printed circuit board as the rectifying transistors.
Let’s now take a look at the secondary of this power supply.