Nexus RX-1.1K Gold Nexus RX-1.1K Gold and its accessories. Highlights of the Nexus RX-1.1K Gold. Specifications of the Nexus RX-1.1K Gold. Outer appearances of the Nexus RX-1.1K Gold. The fan used in the PSU has 11 blades. All connector pins are gold plated to reduce contact resistance. The cable management of Nexus RX-1.1K Gold is partially modular. Acoustic Noise Test EXPERIMENTAL SETUP Fig. A1 shows the test setup for measuring the acoustic noise of a standalone power supply. The test was mainly carried out in an anechoic chamber with a background noise of not more than 16.6 dBA. As shown in the figure, a sound level meter, which was placed 30 cm away from the PSU, was used to measure the acoustic noise (in dBA) emitted by the power supply, whilst the audio output of the sound level meter was connected to a dynamic signal analyzer for recording the sound level pressure (SPL) spectrum. RESULTS & DISCUSSIONS Fig. A2 shows the measured dBA vs output loading for OCZ600SXS and Nexus RX-1.1K Gold. At 600W, Nexus RX-1.1K Gold is approximately 20 dBA quieter than the OCZ600SXS. The measured SPL at almost all operating loads is not more than 25 dBA, which is considered relatively quiet. Fig. A3 shows the SPL spectrum of background noise. Fig. A4 compares the SPL spectra of OCZ600SXS and Nexus RX-1.1K Gold at 600W. Fig. A5 depicts the SPL spectra when the Nexus RX-1.1K Gold supplies 600W and 1000W. CONCLUSIONS Nexus RX-1.1K Gold, with relatively low acoustic noise for its entire operating range, can be an option for users who demand for maximum sound comfort. Power Efficiency Test INTRODUCTION Fig. B1 shows the efficiency level certifications defined by Ecos Plug Load Solutions (previously known as 80 PLUS Website, http://www.80plus.org/). The 80 PLUS certification of ATX PSU with multiple outputs is carried out at 115VAC. Many PSUs with 80 PLUS Gold badges were introduced to the market. Among them is the Nexus RX-1.1K Gold. This report will review the efficiency of the PSU when the input voltage is 240VAC. TEST METHODOLOGY Proper procedure to evaluate the efficiency of a PSU for 80 PLUS certification can be found in the following reference: Generalized Test Protocol for Calculating the Energy Efficiency of Internal Ac-Dc and Dc-Dc Power Supplies, Revision 6.5, July 07, 2010 which was drafted upon the efficiency test protocol outlined in Section 4.3 of IEEE Std. 1515-2000, IEEE Recommended Practice for Electronic Power Subsystems: Parameter Definitions, Test Conditions, and Test Methods. According to the generalized test protocol, the efficiencies of the PSU under test (PUT) are measured at 20%, 50% and 100% of rated nameplate output power. At each loading, the output power drawn from the PUT is distributed across its multiple voltage rails (e.g. +3.3V, +5V, +12V, etc.) as described in Section 6: Loading Criteria For Efficiency Testing (pp. 23) of the reference. Readers may find many PSU reviews on the internet which followed the foregoing load distribution criteria. In this work, the output power was, however, shared only between the +5V and +12V rails as shown in Fig. B2. This will provide readers an option to evaluate the performance of a PSU at other operating conditions. In addition, the load distribution in real world applications can be very much different from one system to another, and may not follow the load distribution as defined in the generalized test protocol. The output load distribution implemented in this work is as following: +5V is constantly loaded at 14A, whilst the +12V loading is increased from 100W to the PUT’s rated output power. As shown in Fig. B2, Fluke 37 digital multimeters were used to measure the voltages and currents of the +5V and +12V rails for output power calculation. On the other hand, the input power was calculated from the input voltage and current data, which were sampled simultaneously by a Tektronix TDS2024B. To minimize the measurement errors, the voltage drop across wires, as stated in Annex B (pp. 74) of IEEE 1515-2000, were taken into consideration for the efficiency calculation. RESULTS & DISCUSSIONS Fig. B3 shows the measured efficiency vs output power for OCZ600SXS and Nexus RX-1.1K Gold. Although this work did not follow the usual loading criteria for 80% PLUS certification, the measured efficiency of the Nexus RX-1.1K Gold with 50% loading is above 90%. Clearly, the Nexus RX-1.1K Gold is about 6% more efficient than the OCZ600SXS at almost every loading condition. Fig. B4 shows the input voltage and current waveforms when the Nexus RX-1.1K Gold supplies 1000W, whilst Fig. B5 shows the harmonic spectrum of the input current. The input power factor and the current total harmonic distortion at output power of 1000W are 0.99 and 7.66%, respectively, which are very close to those measured by Ecos Plug Load Solutions. The overcurrent protection of the PSU was tested and confirmed to work effectively. CONCLUSIONS The measured maximum efficiency of the Nexus RX-1.1K Gold with 50% loading is above 90%. Overcurrent protection circuit of the Nexus RX-1.1K Gold was tested and confirmed to work effectively. Awards BUY HERE .