The FIL-5V-3A precision filament supply, offered by UltraVolt, Inc. (Ronkonkoma, NY), is a center-tapped, non-isolated, low-voltage filament supply rated for 0 to 5 VDC at 0 to 3 Amps. The supply is designed for a variety of beam applications from electron guns to ion beams in devices such as scanning electron microscope inspection tools, focused ion beam workstations, and mass spectrometers. The FIL Series operates in either constant current (CC) regulated mode or constant voltage (CV) regulated mode. Between +26.4 VDC and +21.6 VDC, output line regulation is less than 0.01% in either mode. Units currently exhibit a temperature coefficient of 15ppm/°C in CC mode.