(19)

(11)

EP 0 446 257 A1

(12)

(43) Date of publication: 18.09.1991 Bulletin 1991/38 (21) Application number: 90900020.0 (22) Date of filing: 29.11.1989

(51) International Patent Classification (IPC):  H03M 1/ 38( . ) H03M 1/ 46( . ) (86) International application number: PCT/AU1989/000518 (87) International publication number: WO 1990/006630 (14.06.1990 Gazette 1990/14)

(84) Designated Contracting States: AT BE CH DE ES FR GB IT LI LU NL SE (30) Priority: 29.11.1988 AU 19880001694 (71) Applicant: MAGELLAN CORPORATION (AUSTRALIA) PTY. LTD. Myaree, Western Australia 6154 (AU)	(72) Inventor: BROOKS, David, Robert Perth, W.A. 6000 (AU) (74) Representative: Boydell, John Christopher, et al  Stevens, Hewlett & Perkins 1 Serjeants' Inn Fleet Street London EC4Y 1LL London EC4Y 1LL (GB)