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Telephone conversion unit with multiple memory system

  • US 4,008,380 A
  • Filed: 06/30/1975
  • Issued: 02/15/1977
  • Est. Priority Date: 06/30/1975
  • Status: Expired due to Term
First Claim
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1. In a conventional telephone unit, a converter positioned therein in place of a rotary dialer unit for converting a keyboard coded telephone number to a serial pulse train corresponding to the type generated by said rotary dialer unit, said converter comprising:

  • a. a keyboard switching means having at least ten keys for generating signals corresponding to each of said keys as said keys are depressed,b. an electrical encoder means for converting said signals into parallel four bit signals, each encoder signal uniquely identifying a depressed one of said ten keys,c. a dialer circuit means for converting said encoded signals to a serial pulse train corresponding to the respective keys depressed,d. a bridge rectifier for rectifying the telephone line current conducted to said telephone unit,e. means for generating a supply voltage for said converter, said voltage generating means including means for converting telephone line current coupled to said telephone unit to a voltage only when the hook switch of said telephone unit is closed, and voltage multiplying means for increasing said voltage to a preselected voltage level,f. a first switch for inhibiting current flow through said telephone unit when said dialer generates said pulse train,g. second switching means connected across said telephone unit for interrupting current flow in said telephone lines in accordance with said pulse train, andh. a support structure adapted for positioning in a standard telephone unit in place of a rotary dialer, said support structure supporting said converter in said telephone unit housing.

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