A Look Inside

BeQuiet's Pure Power L8 CM is based on a HEC OEM design. The first hint for a high-quality power supply you can get from the transient filtering stage.

On the primary side you find a rectifier. We can find a PCB housing the CM6800. The CM6800 controls the PFC Booster and the Push-Pull converter. This PSU has a Push-Pull topology using two Mosfets and two Diodes according to the following primary sided principle: link
This is an old school standard topology; simple and proven, but it won't achieve new efficiency records. Because this topology requires hard switching from the Mosfets (Switching Mosfets under voltage and current generates losses) this topology is more and more replaced in the PC PSU market by resonant topologies. The transformer has on the secondary side two coils one for 12V and one for 5V. 3.3V is generated from the 5V Coil. This is the classic old PSU topology.

The APFC Capacitor with 470uF at 400V and 85°C from Teapo. The PFC Booster uses a BCY10-600 Hyperfast recovery diode and 3 60R190C6 Mosfets. This is ok for a PSU in this price range; SiC Diodes are still quite expensive. For rectifying the secondary side Schottky diodes are used. The Output filter Capacitors are from Teapo. 105°C is written on them.

The OCP, UVP, OVP is done by a WT7527.

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Page 1 - Presentation

Page 2 - Photo Gallery

Page 3 - Delivery / Specs

Page 4 - A Look Inside

Page 5 - Input/Output Power and Efficiency

Page 6 - Result Analysis and Discussion

Page 7 - Conclusion