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
Memory device and self interleaving method thereof
Rotating-body electrification mechanism, image carrier unit, process cartridge, image forming apparatus, and method for electrifying image carrier unit
Taxi cab key chain
Signal judgment method, signal judgment apparatus, program, and signal judgment system
MOS resistor apparatus and methods
Horizontal card holder
Scanning optical positioning system with spatially triangulating receivers
  Randomly Featured Patents
Method of packaging a device with a lead frame, and an apparatus formed therefrom
Inkjet printing apparatus and inkjet printing method
Hair cutting edge guide
Radioimmunoassay for benzoylecgonine
Semiconductor device wherein a property of a first semiconductor layer is different from a property of a second semiconductor layer
Method and apparatus for interactively providing information at multiple sites
Electronic mouse
Quieting a thermal expansion valve
Polymer concentrate containing an antistatic agent, process for the production thereof and the use thereof