Hammond 104B 150:80k Ohm Epoxy Potted PCB Input Transformer

The 104B is a miniature input audio transformer from the 104 Series with a very high step-up: a 150 ohm primary into an 80000 ohm secondary. It is designed for P.C. board mounting and suits designers feeding a low-impedance source into a high-impedance input.

Rugged black epoxy potting produces a completely sealed unit that withstands severe environmental conditions, including those of MIL-T-27 (Grade 5, Class S). The 104B uses 0.025 in square pins (drawing tolerance +/-0.005 in) with a series pin length of 0.11 in +/-15%. Unused connections have no pin. The drawing marks the part with a white dot and a stamp on top, and sets a +/-0.030 in tolerance for dimensions not otherwise stated.

Series table ratings are 5 mW output, 1 dB insertion loss and a -1 dB low frequency roll-off at 60 Hz. DC resistance is 6.6 ohms primary and 3730 ohms secondary, +/- 15%, and maximum primary DC is 0 mA. Peak working voltage is 200 V. The drawing rates the 104B at 5 mW over 60 Hz - 20 kHz at a 1 kHz 0 dB level, with 0 mA DC. Its production tests list:

• Iex at 0.9 V, 60 Hz, pins 1-3: 4.8 mA max
• Secondary no-load voltage, pins 4-6: 20.88 V +/-2%
• DCR at 20 degrees C: 6.600 ohms (pins 1-3) and 3760 ohms (pins 4-6), +/-15%
• Hipot primary to secondary: 250 V, 60 Hz, 1 sec

This part is RoHS and REACH compliant and ships at 0.1 lbs (0.05 kg). It follows drawing figure 5.