| Number | Name | Date | Kind |
|---|---|---|---|
| D309600 | Backes | Jul 1990 | |
| D328058 | Suzuki et al. | Jul 1992 | |
| 4935847 | Welsh | Jun 1990 | |
| 5157590 | Barthel et al. | Oct 1992 | |
| 5253140 | Inoue et al. | Oct 1993 | |
| 5289363 | Ferchau et al. | Feb 1994 |
| Number | Date | Country |
|---|---|---|
| 1454600 | Oct 1966 | FRX |
| Entry |
|---|
| Converter module on p. 70 of Electronin Design, Feb. 4, 1993. |