Hammond 183K28 56VA 28V Center-Tapped Dual Primary PCB Transformer

The 183K28 is a 56VA low voltage power transformer for printed circuit board mounting, part of the 183 Series of universal PCB transformers. It is aimed at OEM engineers and electronics designers who need an isolated low-voltage AC supply on a board that must run from either 115 or 230 VAC mains at 50/60 Hz.

The 183K28 provides a 28V C.T. secondary at 2A in series, or 14V at 4A in parallel, from the 56VA K-size core. The dual winding secondaries are non-concentrically wound and can be wired in series, in parallel or used separately; when they are connected in series (pin 9 to pin 10) that junction acts as the center tap.

Construction is a low profile split bobbin with a top shroud, Class F insulation rated 155 degrees C and a 4,000V RMS hipot. Low primary-to-secondary coupling means no electrostatic shield is required. The body measures 3 x 2.5 x 1.81 in (76.2 x 63.5 x 46 mm), with a unit weight of 1.7 lbs (0.77 kg); the shipping weight is 1.59 lbs (0.72 kg).

The transformer uses P.C. board pins on industry standard spacing, with 0.045 in square pins and four hole mounting for #6 screws (mounting screws not provided). Pin numbers are not marked on the unit - the paint dot always identifies the secondary side (pins 12-7). It is cUL listed, with cURus, CE and TUV agency listings shown on its drawing, and RoHS and REACH compliant.