Abstract: A wire fence alarm system 10 comprises a plurality of zones in which a wire or set of wires is stretched between two anchor posts. A sensing post includes sensors for detecting deflection of one of the wires and a processor for generating alarms responsive to signals from the sensors. One or more of the anchor posts comprise rotating members attached to the wires. Use of the anchor post to climb the fence will result in an imbalance in the forces applied to the rotating members by the wires, thereby initiating an alarm condition.

Abstract: A taut wire perimeter fence intrusion detection system is disclosed. The taut wire deflection sensors in the system each include a flexible housing into which is disposed a full resistance bridge having strain gages for each leg. Opposing strain gages in the bridge circuit have predominant directions in common directions. The strain gages are formed directly onto a printed circuit board. An amplifier circuit is also mounted onto the circuit board, for amplifying the differential bridge voltage from the bridge. The taut wire is connected to the housing, for example by way of a slotted bolt and nut, so that horizontal deflection of the taut wire creates strain on the circuit board which is sensed by the strain gage bridge, amplified by the amplifier, and communicated to a data processing system which generates the appropriate alarm condition.

Abstract: An apparatus is provided for monitoring and indicating the amount of material in a hopper or a bin includes self-test circuitry for automatically testing both a material level sensor and circuitry for storing the output signal generated by the sensor. During the normal operation of the monitoring apparatus, the value of the sensor output signal is compared with the values of predetermined maximum and minimum reference signals. If the sensor output signal is greater than the predetermined maximum value or less than the predetermined minimum value, the test circuit generates a failure indication to the operator of the apparatus. In order to test the sensor output signal storage circuitry, the test circuit disables the sensor and generates a simulated sensor output signal to the storage circuitry. The test circuit then compares the stored signal with the simulated signal and generates a failure indication if they are different.

Abstract: An apparatus for monitoring and indicating the amount of material at a given level in a plurality of hoppers or bins includes a detector for sensing and indicating the build-up of the material on the side walls of the hoppers. A sensor positioned at each hopper senses the amount of material at the given level and generates a pulsed output signal which is accumulated over a predetermined time interval to represent the amount of the material at the given level in the hopper. The value of the accumulated output signal is compared with the values of first and second reference signals to generate "full" and "not full" indications respectively. Typically, the indications are a continuous "not full" light when the hopper is empty, a flashing "not full" light as the hopper is filled, a continuous "full" light when the hopper is full, and a flashing "full" light as the hopper is emptied.

Abstract: An apparatus for monitoring the level of material in a plurality of hoppers or bins includes a radiation source and sensor associated with each hopper. Each sensor generates an output signal representing the incidence of radiation passing through the material in the respective hopper. The sensor output signals are supplied to individual sample/hold circuits where they are temporarily stored. A central control circuit cyclically reads the stored signals from the sample/hold circuits and then generates a reset signal to clear the sample/hold circuits. The central control circuit compares the sum of the sensor output signals for each sensor over a predetermined time interval with at least one reference signal representing a predetermined material amount to generate a status signal for each hopper. A plurality of indicator circuits are responsive to respective condition of the status signals for visually and/or audibly indicating to an operator the status of the material level in the associated hopper.

Abstract: A method and apparatus are disclosed for making threaded joints, such as pipe joints, within a range of predetermined applied torque and turns values. A pipe or a pipe and a coupling are threaded onto the end of a pipe string. The applied torque is monitored and, when a reference torque value is exceeded, the number of turns are counted. When either the actual torque or the actual turns exceeds a predetermined minimum value for that parameter and the value of the other parameter exceeds a predetermined minimum value, but is less than a predetermined maximum value, a good joint is indicated and the make-up is stopped. A bad joint is predicted and make-up is stopped when the value of the actual torque divided by the actual turns falls outside a range of values defined by the slopes of a pair of boundary lines and predetermined minimum torque and minimum turn values.

Abstract: A pipe or a pipe and a coupling are threaded onto the end of a pipe string. The applied torque is monitored and, when a reference torque value is exceeded, the number of turns are counted. When either the actual torque or the actual turns exceeds a predetermined minimum value for that parameter and the value of the other parameter exceeds a predetermined minimum value, but is less than a predetermined maximum value, a good joint is indicated and the make-up is stopped. A bad joint is predicted and make-up is stopped when the value of the actual torque divided by the actual turns falls outside a range of values defined by the slopes of a pair of boundary lines and predetermined minimum torque and minimum turn values.

Abstract: An apparatus is provided for making threaded joints, such as pipe joints, including means for storing and indicating values of the actual torque applied to one of the members being rotated with respect to the other member and values of actual turns made by the one member and a d.c. power supply for powering the storage and indicating means. The power supply is connected to a first source of power such as an a.c.-to-d.c. converter for normal operation. The power supply generates a predetermined magnitude voltage and has means responsive to the predetermined magnitude value for switching to a second source of power, such as a battery, when the first source of power fails. The power supply also includes a d.c.-to-d.c. inverter having transistor switching means connected between a transformer and a power source. The transistor switching means are switched on and off to induce current flow in the transformer secondary to generate the power to the storage and indicating means.

Abstract: A method and apparatus are provided for making threaded joints, such as pipe joints, within a range of predetermined applied torque and turns values. A pipe or a pipe and a coupling are threaded onto the end of a pipe string. The applied torque is monitored and, when a reference torque is exceeded, the number of turns made is counted. According to a representative aspect of the invention, when either the actual torque or the actual turns are within a predetermined percentage of a predetermined minimum value for that parameter and the other parameter has exceeded a predetermined minimum value, an indication is generated to the operator of the apparatus that he should be ready to stop the joint making operation.

Abstract: A method and apparatus are disclosed for making threaded joints, such as pipe joints, within a range of predetermined applied torque and turns values. A pipe or a pipe and a coupling are threaded onto the end of a pipe string. The applied torque is monitored and, when a reference torque value is exceeded, the number of turns are counted. When either the actual torque or the actual turns exceeds a predetermined minimum value for that parameter and the value of the other parameter exceeds a predetermined minimum value, but is less than a predetermined maximum value, a good joint is indicated and the make-up is stopped. A bad joint is predicted and make-up is stopped when the value of the actual torque divided by the actual turns falls outside a range of values defined by the slopes of a pair of boundary lines and predetermined minimum torque and minimum turn values.

Abstract: A phase locked loop including a reference oscillator connected to one input of a loop phase detector the output of which is connected through an integrating low pass filter to a voltage controlled oscillator with the output of the voltage controlled oscillator being mixed with a second frequency and compared to the reference in the loop phase detector. The mixer output is also compared to an output of the reference oscillator shifted 90.degree. in a quadrature phase detector, the output of which controls a lock detector which in turn controls a fixed current sink. The fixed current sink is connected to the integrating low pass filter when the loop is in an unlocked condition so that a linear voltage, ramp signal is applied to the voltage controlled oscillator from the output of the integrating low pass filter.