9 systems, namely, air-cooled solid state electro-electronic devices for the conversion of constant 3 phase AC power in controlled variable voltage DC power including main circuit brakes, line inductors, air-cooled bridge, thyristor module with fused protector, blown fuse indicator panel, firing circuit module, rate limit module, current limiting module, logic circuitry, air distributor, associated switchgear and disconnect terminal strips for use as alternative and direct current electrical drivers used with oil and gas drilling equipment
Trademark: 75446488
