1. SA2004 Test conditions: Vout= 5V Iout =50Amp 0-5KGauss

2. Setup

3. To the load SASY2000 Vout CHon Vset

4. SASY2000

5. Address + - PWR 48V IN Communications 48V sig. Fuse Earth SASY EXTERNAL PWR48

6. 48V sig. SY2527. Communications

7. Instruments: -n°1 48V LAMBDA JWS600 Power supply -n°1 Branch Controller -n°1 80V 50A 400W/CH MAX Active load -n°1 Oscilloscope TEKTRONIX YHS720P -n°1 Rshunt 20Amp 10mOhm -n°1 Rshunt 50amp 50mV -n°1 SASY -n°1 System SY2527 -n°1 Tester Goldstar DM-332

8. Waveform across the transfomer primary 0KGauss 5KGauss 20V/Div 60V 0 -60V 1usec/Div 1KGauss2KGauss 3KGauss4KGauss

9. Current absorbed by the primary’s power supply, measured on a 33 mOhm load 0KGauss 1usec/Div 0 33A/Div 1KGauss2KGauss 4KGauss5KGauss3KGauss 23A 20A 26.4A 33A 34A 40A

10. Effect Reduction of the dead time on the transformer drive. Increment of the absorbed current. Cause Reduction of the magnetization inductance Increment of the dissipated inductance

11. Vrin: drop over the 10 mOhm shunt resistance in series to the Pwr 48V Iin-Choff: current absorbed by the SASY with the channel off VinSASY: Pwr 48V Pin: power absorbed by the SASY with the channel off Iin-Chon: current absorbed by the SASY with the channel on IinCH: current absorbed by the channel (IinChon-IinChoff) VinCH: channel input voltage Pi-CH: power provided by the Pwr 48V with the channel on Vout: channel output voltage Iout: current provided by the channel Po-CH: power over the load Po/Pi%: percentage efficiency of the channel

13. Conclusions The channels have behaved as foreseen during the project phase, this is the reason why components which could stand a larger current stress have been chosen. Proposals According to the data resulting from these tests, CAEN Power Supply is realizing the revisions of the tested boards in order to improve their performance in magnetic field

14. Acknowledgements : For the test runs we wish to thank the following people: G. Stefanini, S. De Pasquale, F. Cindolo (ALICE) L. Periale (CERN ESS-EP)