Comparison of switching mode power supplies

Laboratory practical
Tutor: M.Sc. Muhammad Bilal Saif
By Mitja Stachowiak Open Booklet

Introduction

Idea:
Tested power supplies:

Hama Ultra Slim Power Supply, 00054190
Cooler Master, RP-120-USNA-J1
Clevo P150HM, FSP180-ABAN1
TDK CME150-24

What to measure?

voltage and current stability
efficiency
reactive power
thermal resistance
influence of an internal power supply on the mainboard
distortion
jitter

What questions to answer?

Are compact power supplies less efficient?
What efficiency factor required for internal power supply?
What surface material to use?

Input and output

{ x:'Iout', y:[['Hama', 'Uout'], ['Clevo', 'Uout'], ['CoolerMaster', 'Uout'], ['TDK', 'Uout']] } { x:'Iout', y:[['Hama', 'eff'], ['Clevo', 'eff'], ['CoolerMaster', 'eff'], ['TDK', 'eff']] } TDK manufacturer sais efficiency was 82% Clevo and CoolerMaster measurement unprecise!

Heatup

Hama manufacturer sais there was an overheating protection { x:'time', y:[['hama_high', 'tempIn'], ['hama_high', 'tempOut'], ['Clevo', 'tempOut']] } { x:'tempOut', y:[['hama_high', 'eff'], ['Clevo', 'eff']] } { x:'tempOut', y:[['hama_high', 'VAr_'], ['Clevo', 'VAr_']] } { x:'tempOut', y:[['hama_high', 'Uout'], ['Clevo', 'Uout']] }

Infrared

{ action : function () { this.drag.value = 1; } } { action : function () { document.getElementById('InfraredVideo').currentTime = 0; document.getElementById('InfraredVideo').play(); this.drag.value = 0.3; } } { action : function () { document.getElementById('InfraredVideo').currentTime = 120; } } { action : function () { document.getElementById('InfraredVideo').currentTime = 240; } } { action : function () { document.getElementById('InfraredVideo').currentTime = 458; document.getElementById('InfraredVideo').pause(); this.drag.value = 0.3; } }

Simulation resistor
Provide 21 W to the resistor (≙ 89.4% efficiency)
Simulation resistor Pic 1: Resistor with metal surface (Ti = 123 C, Ts = 82 C) Pic 2: Resistor with plastic tape surface (Ti = 111.6 C, Ts = 68.5 C) Pic 3: Resistor in laptop (Ti = 118.2 C, Ts* = 47.6 C)
For benchmarking (and Pic. 5 & 6) power was reduced to 10.5W (≙ 94.4% efficiency)
P150EM, Quadro K5000M benchmark
HP 8770W, Quadro K5000M benchmark temperature without resistor stable at 69 C t1: Add resistor, temp. stable at 74 C t2: temperature at an other viewpoint + 2 K t3: temperature at previous viewpoint again 74 C

Input Signal { content : 'Input Signal: Clevo' } { content : 'Input Signal: Hama' } { content : 'Input Signal: TDK' }

{ staticIndicators:{Iout:0}, x:'time', y:[['Clevo', 'Upri'], ['Clevo', 'Ipri']] } { staticIndicators:{Iout:1}, x:'time', y:[['Clevo', 'Upri'], ['Clevo', 'Ipri']] } { staticIndicators:{Iout:5}, x:'time', y:[['Clevo', 'Upri'], ['Clevo', 'Ipri']] } { staticIndicators:{Iout:10}, x:'time', y:[['Clevo', 'Upri'], ['Clevo', 'Ipri']] } { staticIndicators:{Iout:0}, x:'time', y:[['Hama', 'Upri'], ['Hama', 'Ipri']] } { staticIndicators:{Iout:1}, x:'time', y:[['Hama', 'Upri'], ['Hama', 'Ipri']] } { staticIndicators:{Iout:5}, x:'time', y:[['Hama', 'Upri'], ['Hama', 'Ipri']] } { staticIndicators:{Iout:0}, x:'time', y:[['TDK', 'Upri'], ['TDK', 'Ipri']] } { staticIndicators:{Iout:1}, x:'time', y:[['TDK', 'Upri'], ['TDK', 'Ipri']] } { staticIndicators:{Iout:5}, x:'time', y:[['TDK', 'Upri'], ['TDK', 'Ipri']] }

Output Signal

{ x:'time', y:[['Hama_res', 'Isec']] } AC measured, DC part is mostly just assumed! { x:'time', y:[['TDK_res_realDC', 'Isec']] } { x:'time', y:[['Clevo_res', 'Isec']] } { x:'time', y:[['Clevo_P150HM_Idle', 'Isec']] } { x:'time', y:[['Clevo_P150HM_Idle', 'Isec'], ['Clevo_P150HM_battLoading', 'Isec']] }

Conclusion

Output voltage is stable, negligible dependency of I and T
Compact power supplies are not less efficient
Most power losses are caused by the transistors and the transformers
Metal is unsuitable for surface material
More than 94% of efficiency required for ODD bay power supply
Power factor correction is a major issue when designing switched-mode power supplies