Hammond 162H20 20VA 20V CT Dual-Primary PCB Power Transformer

The 162H20 is a 20VA low-profile power transformer for printed circuit board mounting, built with a universal dual primary rated 115/230V and a 20V center-tapped secondary rated 1A RMS in series connection. Wired in parallel, the two secondary windings deliver 10V at 2.0A. It suits OEM engineers and designers who need one board-level transformer for equipment that may run from either 115V or 230V mains at 50/60 Hz.

Construction uses a split bobbin with dual, non-concentrically wound secondaries, which keeps primary-to-secondary coupling low so no electrostatic shield is required. Insulation is Class B (130 degrees C) and the part is hipot rated at 2,500V RMS; the drawing specifies the primary-to-secondary test as 2500V, 60Hz for 1 second. The unit is designed so that all windings must be used, and pin numbers are embossed on the bobbin flange for identification.

On the series mechanical table the H-size body measures 2.25 in long, 1.88 in wide and 1.44 in high, with a listed weight of 0.8 lbs; the shipping weight is 0.8 lbs (0.36 kg). It is a P.C. board mount design with industry standard pin spacing and two-hole mounting for #4 screws; mounting screws are not provided.

Electrical test acceptance criteria on the 162H20 drawing include a maximum excitation current of 91.2mA at 115V, 60Hz across pins 1–2, secondary no-load voltages of 11.90V on each winding (pins 5–6 and 7–8, ±2%), and DC resistance at 20°C of 69.51 Ω per primary winding and 0.863 Ω per secondary winding (±20%). The part is RoHS and REACH compliant and the series is c UL us recognized. A single 115V primary version of the same output is listed as 164H20.