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
Device and method incorporating an improved text input mechanism
In-store marketing sign
Direct chemical vapor deposition of graphene on dielectric surfaces
Semiconductor devices and methods for changing operating characteristics and semiconductor systems including the same
Sub-resolution assist feature repair
Distylium plant named `PIIDIST-I`
Method for forming ventilation holes in an electrode plate
  Randomly Featured Patents
Image forming apparatus showing preview of finishing as applied to sample image
Method for forming molded portion at end of extruded weather strip
Exterior-coated nitrile rubber article having natural rubber characteristics
Endoscopic suturing machine
Focusing system
Temperature controlled core rod
Self-cleaning foam-dispensing device
Prioritized content recording and storage management
Cruciform display