The URD-301A Resonant Scanner Driver is a variable amplitude self-oscillating resonant driver capable of driving ESI’s line of fixed frequency scanners.  The scanner is driven with a square wave at its resonant frequency.  The amplitude of the scanner oscillation can be varied from 20% to 100% of rated angle.  The driver maintains the operating frequency and scan angle of the scanner by closing the loop around the pickup coil on the scanner.