Hammond 166U5 5V CT 15A Open Style Power Transformer, 75 VA

The 166U5 is a 75 VA open style power transformer providing a 5 V centre-tapped secondary at 15 A from a 115 V, 60 Hz primary. The high current at low voltage makes it a fit for filament strings, low-voltage lamp and heater circuits, and rectified low-voltage DC supplies in OEM and bench equipment.

Construction follows the 166 Series design: an open style unit on a channel bracket, a dual bobbin winding arrangement that needs no electrostatic shield, and Class B insulation rated to 130 °C for extra protection, while the transformer is UL listed as a Class A (105 °C) design. Every unit is hi-pot tested at 2,000V RMS, and it is supplied with minimum 6 in long leads. With 15 A available, the 166U5 sits above the 10 A 166S5 in the 5 V C.T. line-up of this series.

Overall dimensions are A 4.03 in (102 mm), B 2.25 in (57 mm) and C 2.63 in (67 mm). The 166U5 mounts with two holes of 0.187 in (4.7 mm) spaced 3.56 in (90 mm) hole to hole (mounting reference C). Shipping weight is 2.5 lbs (1.13 kg). On the drawing schematic the primary leads are black (BLK/BLK) and the secondary leads are green (GRN/GRN) with a green/yellow (GRN/YEL) centre tap.

The transformer is UL listed and CSA certified, and it is declared RoHS and REACH compliant. Check the 115 V, 60 Hz primary against your supply before ordering; for 117/234 V or 50/60 Hz operation across the range, or dual secondaries, the manufacturer points to its 266 Series.