Activated from 3.3VDC to 24 VDC via a heavy-duty relay Optically – coupled with full automatic reset. 40% more efficient than EI type. Separate bi-filar windings for each channel guaranty lower noise and crosstalk. Double-sided, FR-4 glass-epoxy, computer-grade boards are assembled in-house. Ultra soft turn on reduces in-rush current to a minimum. Multiple units can be turned on without tripping circuit breakers eliminating the need for sequencing. High-current, bi-polar and ThermalTrak output transistors insure optimized performance in real-time. 59,400 µF (microfarads) per channel. Dual detachable, 3-wire cord. Parts and labor against defects in parts or workmanship. 17 1/4"W X 9 1/2"H X 18 1/2"D (without feet: H=8 3/4") 88 to 138 lbs (model dependent)