Hammond 141M 30K to 1200CT Ohm Low Profile PCB Audio Transformer

The 141M is a 141 Series low profile audio transformer that mounts directly on a P.C. board, pairing a 30K ohm primary with a 1200 ohm center-tapped secondary. It is aimed at engineers designing compact audio boards who need a high impedance primary feeding a center-tapped secondary.

Note that the manufacturer's specification sheet states the 141M is incorrectly listed with a 300K primary impedance in its latest catalogs; the primary is actually 30K, as shown in the series table and the part drawing.

The 141M is rated for 100 milliwatts output with a maximum primary D.C. current of 2 mA. Series-table D.C. resistance is 1100 ohms primary and 47 ohms secondary. The drawing lists 1.604K ohms across primary pins 1-3 and 56.77 and 55.10 ohms across secondary pins 4-5 and 5-6, each ±20%. Typical primary inductance is 11.75 H (51.5K ohm impedance) at 1 kHz, 1 V open circuit, and leakage inductance is 109.50 mH.

Frequency response is 200 Hz to 50 kHz within ±1.0 dB referenced at 1 kHz. Dielectric strength is 250 VRMS and temperature class is up to 105 °C. The low profile, open type body uses a 29M6 silicon lamination core and pins 0.25" long by 0.035" diameter; net weight is 0.6 oz. It is RoHS and REACH compliant.