FOUR QUADRANT DC TO DC SWITCHING SUPPLY FOR THE

The Fermilab Main Injector (FMI) will require 248 ramped corrector power supplies for the operation of the accelerator. The design and prototype test results will be described in this paper. The 3 main design goals for these supplies are: 1) eliminate failure due to thermal fatigue that has plagued similar systems at FNAL, 2) utilize PWM technology to attain good efficiency and small size, and 3) minimize conducted and radiated noise typically generated by PWM systems. The power supplies operate at 30kHz switching frequency and are rated for +/-150 Volts and +/-15 Amps at 95 percent switching duty cycle and 95 percent efficiency into a 1 Henry magnet load. The FMI requirements call for a ramp cycle of 1- 2 seconds. During the cycle, the maximum temperature swing, junction to heat sink, of the power components is less than 30 degrees centigrade. The output voltage ripple is less than 1 Volt RMS