Hammond 229D20 48VA 20V C.T. Low Profile PCB Mount Transformer

The 229D20 is a 48 VA dual-primary power transformer from the 229 Series, designed for low profile mounting directly on a printed circuit board. It suits OEM engineers and electronics designers who need an on-board low voltage supply: wired in series, the secondaries deliver 20V C.T. @ 2.4A (center tapped); wired in parallel, they deliver 10V @ 4.8A. At 48 VA it is the largest power size in the 229 range, which spans 2 VA to 48 VA.

The transformer uses a dual - split bobbin with a semi-toroidal design. That construction gives low primary to secondary coupling and balanced windings, so no electrostatic shield is required, and it keeps EMF radiation low. The universal dual primary is rated 115/230V at 50/60 Hz, so the same part can be wired for either line voltage. Insulation is Class B (130 degrees C) with a hipot rating of 1,750V RMS.

Per the 229D20 drawing, the body measures A 2.50" (64 mm), B 3.12" (79 mm) and C 1.38" (35 mm), with D 0.60" (15 mm), D1 0.66" (17 mm) and E 2.18" (55 mm). PC board spacing is 1.50" (38 mm) and the pin size is 0.04" x 0.04" (1 mm x 1 mm). Rated regulation is 15%, and the shipping weight is 1.55 lbs (0.70 kg).

With 2.4A available from the 20V center-tapped winding, or 4.8A at 10V in parallel, this 48 VA size is aimed at boards that need more current than the smaller 229 sizes provide. The part is C UL US recognized under UL file E207860 and is listed as RoHS and REACH compliant. Identifiers: UPC 623980271644, UNSPSC 39121301.