Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4885563 | Power line carrier communication system | Richard A. Johnson, Dirk J. Boomgaard | 1989-12-05 |
| 4885564 | Power line carrier communication system for monitoring refrigerated containers | Leonard C. Vercellotti, David A. Christiansen, Dannis R. Johnson, Laurence R. Brickner, Robert G. Colclaser III +1 more | 1989-12-05 |