Hammond 108P 10K:1.5K Ohm Center-Tapped Potted PCB Audio Transformer

The 108P is a miniature epoxy potted audio transformer from the 500 mW-rated 108 Series, built for printed circuit board mounting. It couples a 10K ohm center-tapped primary to a 1.5K ohm center-tapped secondary, for matching a high-impedance source into a medium-impedance input. Designers of audio input, line matching, isolation and output stages will find it a compact, board-level way to add transformer coupling.

Nominal impedances are 10K ohm CT on the primary (pins 1-3) and 1.5K ohm CT on the secondary (pins 4-6). The ordering table lists D.C. resistance of 1050 ohms primary and 180 ohms secondary (+/- 20%) and a maximum D.C. unbalance of 1.5 mA. The part drawing gives typical values of 438Ω (255Ω/183Ω) primary DCR, 9.0 H primary and 1.60 H secondary inductance, 3.50 H leakage inductance, a 2.58:1 turns ratio and 500 Vrms dielectric strength.

The series is rated 500 milliwatt (+/- 1.5 db, 300 Hz. - 50 KHz.), and the 108P drawing lists a power level of 150 mW from 300 Hz to 50 kHz with typical output power of 0.500 W. Frequency range is 300 Hz to 50 kHz +/- 1.5 dB at +0 dBm and 300 Hz to 100 kHz +/- 1.5 dB at +20 dBm, measured with no D.C. saturation. Power ratings are maximum at the lowest frequency, and the secondary may be used as the primary and vice versa.

Construction is rugged epoxy potting in a black molded case, producing a completely sealed unit, with pin type P.C. board terminals of at least 0.187" length. The part withstands soldering for 10 seconds at 260 °C, is rated for 85 °C maximum ambient, and the casting epoxy has a workable range of -40 °C to +105 °C. It is RoHS and REACH compliant, made in Canada, and ships at 0.08 lbs (0.04 kg).