Abstract: A method of controlling a refrigeration case of a refrigeration system including the steps of locating an expansion valve of a refrigeration case, moving the expansion valve of the refrigeration case out of a predetermined position, sampling temperature readings from an evaporator coil of a refrigeration case, calculating an adaptive proportional-integral-differential (PID) of the temperature of the evaporator coil for the refrigeration case, and moving the expansion valve to a second position closer to the predetermined position based on the calculated proportional-integral-differential until the temperature of the evaporator coil for the refrigeration case is within a predetermined temperature range.

Abstract: A method of controlling a plurality of commonly piped compressors for a refrigeration system having a plurality of refrigeration cases including the steps of sensing a suction pressure of the refrigeration system, determining whether the sensed suction pressure is within a predetermined pressure range, and turning compressors ON or OFF in stages until the suction pressure is within the predetermined pressure range. The method also includes the steps of sensing a case temperature for each of the refrigeration cases if the sensed suction pressure is within the predetermined pressure range and determining whether the sensed case temperature is within a predetermined temperature range.

Abstract: A pair of thermistors are mounted in a tube which diverts a minor portion of the air flowing through a duct of an HVAC system. One thermistor is heated by a feedback control system to maintain a substantially constant temperature differential between the thermistors. A signal representing the flow velocity is detected by detecting the power which is applied to the heating body to maintain the constant differential. That power represents the thermo power being carried away from the heated body. The temperature of the unheated thermistor is also detected. The signals are converted to digital form and applied to a computer for computing the flow rate in the ducts.

Abstract: A method and apparatus for use in scientific measurement analysis and control. Travelling interference fringes are generated by radiating at least two different periodic waves at two different frequencies, one from each of two different radiators. The waves are received, mixed and filtered to detect at least one beat signal from these waves which represents the travelling interference fringe. The phase of that beat signal is detected relative to a reference signal of the same frequency as the beat signal. The radiated waves may be received at a second antenna and the phase of the beat of the waves at the first antenna is compared to the phase of the beat as observed at the second antenna. A third wave may be radiated from the first antenna to provide a reference signal which is the beat generated by the third wave and the other wave from the same radiator.

Abstract: An apparatus and method suitable for automatic machine interrogation of individuals for identifying or analyzing persons such as those seeking admittance to secure areas or seeking an extension of credit. Physical vibration wave energy is applied by a signal generator and transducer to the person's body at a selected point such as the finger tips. The frequency and/or the time function of force and/or motion parameters at the driving point of the body are then detected and stored. Comparison of a previously known function with a subsequently measured function to determine whether they are within preselected tolerances permits a machine decision whether the functions represent the same person.

Abstract: A burglar deterrent switch for installation in a conventional manual switch box for controlling room lights. An electronic sound responsive timing switch illuminates the room lights for a selected period of time in response to the occurrence of a sound and then turns the lights off for another selected period of time. The timing switch has a triac which is shunted across the manual light switch. The gate of the triac is controlled by an SCR connected in a bridge rectifier for controlling the triac gate current. The gate of the SCR is connected to the output of an amplifier and is switched on by sound incident upon a sound transducer connected to the input of the amplifier. A timing circuit means is also connected across the SCR and comprises a pair of voltage reference diodes connected parallel to a capacitance for fixing the voltage to which the capacitance may charge and having a resistance series connected to the parallel diodes and capacitance.

Abstract: An apparatus for use in the medical diagnosis of human and other bodies and also for use in the automatic machine interrogation of individuals for identifying persons such as those seeking credit or admittance to a security area. Oscillatory wave energy, preferably a sonic signal, is applied with a selected polarization to a first part of a body. The polarization of the wave energy transmitted through a portion of the body is detected at a second part of the body. Data representing the shift in polarization is stored for subsequent comparison to a polarization shift which is subsequently measured by the same steps. Comparison of the data representing the two polarization shifts can be used for quantitative and qualitative medical diagnosis as well as for an automatic machine decision whether the polarization shifts are sufficiently similar that they were derived from the same individual. The use of multiple frequencies permits the derivation of a polarization shift characteristic over a range of frequencies.

Abstract: A device for use in an enclosure associated with an audio speaker or other sound producing device and which permits relatively large volume changes within the enclosure as a result of relatively small pressure changes so that relatively small enclosures can be as effective as enclosures of larger volume. The device reduces the energy required from the speaker to change the volume of the interior of the enclosure. The device has a displaceable walled container having an expansible and contractible volume containing a composition of matter at gas phase/liquid phase equilibrium at its boiling point under atmospheric or other ambient pressure. The composition of matter preferably selected is one having the characteristic that relatively large volumes undergo a phase change for relatively small energies. The composition is heated to its boiling point. The heater is actuated by a volume responsive switch to maintain the container within a selected range of volume.

Abstract: A method for the medical diagnosis of human and other bodies and also for use in the automatic machine interrogation of individuals for identifying persons such as those seeking credit or admittance to a security area. Oscillatory wave energy, preferably a sonic signal, is applied with a selected polarization to a first part of a body. The polarization of the wave energy transmitted through a portion of the body is detected at a second part of the body. Data representing the shift in polarization is stored for subsequent comparison to a polarization shift which is subsequently measured by the same steps. Comparison of the data representing the two polarization shifts can be used for quantitative and qualitative medical diagnosis as well as for an automatic machine decision whether the polarization shifts are sufficiently similar that they were derived from the same individual. The use of multiple frequencies permits the derivation of a polarization shift characteristic over a range of frequencies.

Abstract: An electronic apparatus and method suitable for automatic machine interrogation of individuals for identifying persons such as those seeking admittance to secure areas or seeking an extension of credit. Acoustical wave energy is applied by an oscillator and transducer to the person's body, such as one end of an arm. Another transducer contacts another body part, such as the other end of the arm, to receive the body-transmitted energy. The frequency response characteristics of the body part are then detected by suitable correlation means to determine the amplitude and phase transfer functions. Comparison of a previously known transfer function of a person with a subsequently measured transfer function permits a machine decision whether the functions represent the same person.