Huntkey Balance King 5000 500 W Power Supply Review
Secondary Analysis
Contents
Huntkey Balance King 5000 has six Schottky rectifiers attached to its secondary heatsink.
Since this power supply uses a half-bridge configuration to calculate the maximum theoretical current each output can deliver is easy: all we need to do is to add the maximum current supported by all diodes.
The +12 V output is produced by three of the available rectifiers. Two STPS30H100CT Schottky rectifiers are connected in parallel, each one supporting up to 30 A (15 A per internal diode at 155° C, 0.93 V maximum voltage drop). This gives a maximum theoretical current of 60 A or 720 W for the +12 V output (Balance King 4500 has two 20 A rectifiers here). The third Schottky rectifier, an STPS4045CW, has its two diodes connected as “freewheeling” diodes, a rather unusual configuration for a half-bridge power supply.
The +5 V output is produced by two STPS2045CT Schottky rectifiers connected in parallel, each one capable of delivering up to 20 A (10 A per internal diode at 155° C, 0.84 V maximum voltage drop), giving us a maximum theoretical current of 40 A or 200 W for the +5 V output. Here it is interesting to note that the 450 W model uses two 30 A rectifiers here, i.e., it has a higher maximum theoretical current/power.
The +3.3 V output is produced by one STPS4045CW, which can handle up to 40 A (20 A per internal diode at 130° C, maximum voltage drop of 0.94 V), which translates in a maximum theoretical power of 132 W. The 450 W model uses two 30 A rectifiers here, providing a maximum theoretical current/power.
All these numbers are theoretical. The real amount of current/power each output can deliver is limited by other components, especially by the coils used on each output.
Figure 13: +3.3 V rectifier, one of the +5 V rectifiers and the two +12 V rectifiers.
Figure 14: +12 V freewheeling rectifier and the other +5 V rectifier.
The monitoring circuit is built using three LM339 integrated circuits (each one has four voltage comparators inside).
Figure 15: Monitoring circuit.
The capacitors on the secondary are from Teapo and Fcon.
