Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5041745 | Failsafe bandpass filter/decoder | — | 1991-08-20 |
| 4878638 | Combination frequency loop coupling for railway track signalling | James R. Hoelscher, Klaus H. Frielinghaus, Barry L. Smith | 1989-11-07 |