Distribution power line communication system including a messeng

Do not disturb doorbell

Dog bark door bell notification and personal protection system

Domestic appliance control and display panel

Door alarm controlled by operation of door lock

Door alarm system responsive to forced entry

Door alert system and magnetic switch therefor

Door operator with automatic control of auxiliary circuit

Door station apparatus with electric lock

Doorbell base

Doorbell for pets

Doppler detection device with integrator sampling means to inhib

Doppler detection device with phase shift means to inhibit false

Doppler perimeter intrusion alarm system using a leaky waveguide

Doppler shift actuator and intrusion systems

Dot matrix converter

Double detection circuit for conserving energy in fire detection

Double oscillator battery powered flashing superluminescent ligh

Double-detecting loop type alarm system

Down marker indicator for football competition