Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M19/00—Current supply arrangements for telephone systems
  • H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
  • H04M19/04—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone the ringing-current being generated at the substations
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/30—Modifications for providing a predetermined threshold before switching
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
  • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
  • H03K3/26—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback
  • H03K3/28—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback
  • H03K3/281—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator
  • H03K3/286—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator bistable
  • H03K3/2893—Bistables with hysteresis, e.g. Schmitt trigger

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Power Engineering (AREA)
• Devices For Supply Of Signal Current (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4093910

Family Applications (1)

Country Status (6)

Families Citing this family (13)

Family Cites Families (3)

• 1972
  • 1972-07-24 CA CA147,766A patent/CA968477A/en not_active Expired
  • 1972-09-12 US US00288410A patent/US3772470A/en not_active Expired - Lifetime
• 1973
  • 1973-02-13 GB GB690973A patent/GB1415461A/en not_active Expired
  • 1973-04-04 JP JP3861673A patent/JPS5319367B2/ja not_active Expired
  • 1973-06-05 FR FR7320444A patent/FR2194094B1/fr not_active Expired
  • 1973-07-11 NL NL7309680A patent/NL7309680A/xx not_active Application Discontinuation
• 1974
  • 1974-02-04 US US43906574 patent/USRE28283E/en not_active Expired

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