Credit card verifier using transformers
作者： Max Norman Schweizer
DOI:
关键词:
摘要:
lens.org 参考文章(5)
William H Wolowitz, Record card with selective conductive marks ,(1951)
John D Helms, Jr Herbert L Brown, Apparatus for use with a credit card ,(1963)
Frederick M Demer, Martin J Kelly, Magnetic data processing ,(1959)
Gene D Barber, Blocking oscillator comparator ,(1960)
Thomas J Schinner, Embossed card reading device ,(1963)