Hammond 270EX 118 VA Plate Transformer, 550V C.T. 144mA, 5V/6.3V

The 270EX is a 118 VA high voltage (plate) and filament transformer designed for 115 VAC, 60 Hz. It delivers a 550V center-tapped secondary rated at 144 mA along with a 5V @ 3A winding and a 6.3V @ 4A filament winding, suiting builds that need more plate and filament current than the smaller 550V models provide.

Electrically, the 270EX is rated 118 VA with a 115 VAC, 60 Hz primary, a high voltage secondary rated 550V C.T. @ 144mA (RMS), and filament windings of 5V @ 3A (#1) and 6.3V @ 4A (#2). As with every 200 Series unit, it can be run full wave bridge or full wave C.T. Compared with the 270DX, it raises the high voltage current from 104 mA to 144 mA and the filament ratings to 3A and 4A.

The case is an enclosed, 4 hole, chassis mount design in the vertical (X) mounting style, with minimum 6 in long leads. Listed dimensions are A 2.50 in (64 mm), B 3.75 in (95 mm), C 3.06 in (78 mm), D 2.00 in (51 mm), F 2.69 in (68 mm), with 0.20 in (5 mm) x 0.38 in (10 mm) mounting slots. Shipping weight is 4.5 lbs (2.04 kg).

For the primary, the 200 Series wiring notes describe two choices: use the white and gray wires and tape the black wire for 115 VAC input, or use the white and black wires and tape the gray wire where roughly 125V line voltage is producing too high a secondary voltage. Never connect power to both the gray and black wires at once. Insulation is Class A (105 degrees C), units are hi-pot tested at 2,000V RMS, the design is CSA certified (209651), and the part is RoHS and REACH compliant.