A transformer board is disclosed. In some embodiments, the transformer board includes a base, a circuit board, a transformer having a first and second winding, a first and a second connector, a ribbon cable and a nonconductive fill material. The base has a recess within which the circuit board is positioned. The transformer is mechanically coupled to the circuit board. The first connector is configured to electrically couple to transducers within a pressure boundary of an ultrasonic flow meter and is electrically coupled to the second winding of the transformer. The ribbon cable is electrically coupled between the first winding of the transformer and the second connector. The nonconductive fill material is contained by the recess and encases the circuit board, the transformer, the coupling of the first connector to the second winding of the transformer, and the coupling of the ribbon cable to the first winding of the transformer.