@LDV
28-12-2009, 17:22
75936
75934
75939
75938
75937
75935Inductive cards
Brasil is the home of inductive technology which was invented in 1978 by Nelson G.Bardini, an engineer, who first demonstrated the card at a national inventors' exhibition in 1982, winning the first prize. This was awarded by Telebras, the national telecommunications organization.
Even if prototype phone cards appeared in 1987, it was another five years before the cards could be tested in public trials, the earliest of which took place at the airport in Rio, and public issues began later the same year.
The inductive system is considered to be cheap and reliable, yet very sicure, and operates through electrical induction coils (there are 104 in each card). The telephone contains another coil which 'searches' for an unused coil and 'blows' it like a fuse when it is spent. There is. however, no visible difference between mint and used cards, other than that indicated by the presence or absence of a wrapper. Inductive system is used mainly in Brasil, but trials have been conducted in Bolivia, China, Nicaragua and Nigeria.:-h
75934
75939
75938
75937
75935Inductive cards
Brasil is the home of inductive technology which was invented in 1978 by Nelson G.Bardini, an engineer, who first demonstrated the card at a national inventors' exhibition in 1982, winning the first prize. This was awarded by Telebras, the national telecommunications organization.
Even if prototype phone cards appeared in 1987, it was another five years before the cards could be tested in public trials, the earliest of which took place at the airport in Rio, and public issues began later the same year.
The inductive system is considered to be cheap and reliable, yet very sicure, and operates through electrical induction coils (there are 104 in each card). The telephone contains another coil which 'searches' for an unused coil and 'blows' it like a fuse when it is spent. There is. however, no visible difference between mint and used cards, other than that indicated by the presence or absence of a wrapper. Inductive system is used mainly in Brasil, but trials have been conducted in Bolivia, China, Nicaragua and Nigeria.:-h