Resources Contact Us Home
Method of and apparatus for selectively controlling a plurality of remotely located loads

Image Number 4 for United States Patent #3964023.

A master controller is connected via a pair of wires to a plurality of loads and is capable of generating pulses having either positive or negative polarity and a voltage level either above a first threshold or below a second threshold or above the second threshold. Some of the slave units connected via these two wires to the master controller are singly handicapped and have a single zener diode whose avalanche voltage corresponds to the first threshold so that the load is energized whenever this first threshold is exceeded. Other units have a second zener diode in series of the first diode and itself having an avalanche voltage equal to the second threshold so that only when this second threshold is exceeded is the load energized. In such a system it is possible to provide a memory circuit to short circuit this second zener diode if it is desired to remove the double handicap and partially emancipate the slave unit. This memory circuit may comprise a thyristor connected across the second zener diode so that if the voltage in the input lines to the slave unit drop to zero the emancipation command from the memory is eliminated. In addition some of the slave units are connected via full-wave rectification bridges to the two conductors so that regardless of the polarity of the pulses they are energized, whereas others of the units do not have such fall-wave rectification so that reversal of the signal polarity cuts these slave units out.

  Recently Added Patents
Communication apparatus, communication method, and communication system
Detection of bioagents using a shear horizontal surface acoustic wave biosensor
System and method for content delivery
Nucleotide sequence coding for variable regions of .beta. chains of human T lymphocyte receptors, corresponding peptide segments and the diagnostic and therapeutic uses
Carrier or transport strip
System and method of creating and providing SMS http tagging
Method for reserving network bandwidth for versioned network services
  Randomly Featured Patents
Arrangement for feeding flat sample bags into further processing
Cordless telephone base
Cherry rootstock: Brooks-2 cultivar
Control device for multiple lamp currents of liquid crystal display backlight source
Information processing apparatus, information processing method, and transmitting medium
Handset front cover
Hydrothermal crystal growing process
Gamma camera stabilizer
Incoming telephone call director
Coating of film-forming resin and functional flow control copolymer