Devices which can set up and transmit only one digit at a time

Full Title

Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M3/00; prepayment telephone coin boxes H04M17/00; current supply arrangements H04M19/08) > Devices for calling a subscriber (H04M1/66 takes precedence) > Devices which can set up and transmit only one digit at a time

Child Classifications

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• H04M 1/31 by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses
• H04M 1/50 by generating or selecting currents of predetermined frequencies or combinations of frequencies