Abstract: A refrigerant charging system and method for charging a refrigeration system with refrigerant includes a refrigerant source, one or more cartridges, an input line, an output line, and a scale preferably having an accuracy within about ±0.2 ounce. The cartridge is filled with refrigerant by transferring the refrigerant from the refrigerant source to the cartridge, after which, the filled cartridge is disconnected from the refrigerant source. An initial weight of the filled cartridge is obtained, and the cartridge is connected to the refrigeration system. Refrigerant is then transferred from the filled cartridge to the refrigeration system. A revised weight of the filled cartridge is obtained, and the revised weight is compared to the initial weight to determine if the refrigeration system has been completely charged. The cartridge is disconnected from the refrigeration system after the refrigeration system has been completely charged.

Abstract: A refrigerant charging system and method for charging a refrigeration system with refrigerant includes a refrigerant source, one or more cartridges, an input line, a scale, a pressure sensor and a temperature sensor. The input line connects the refrigerant source to the cartridge. A valve is disposed between the refrigerant source and cartridge. The scale measures the weight of the cartridge. The pressure and temperature sensors adjust the remaining refrigerant that ensures full charge on the refrigeration system. A heater can be connected to the refrigerant source to raise the temperature of the refrigerant within the refrigerant source, and a controller can be attached to the components of the refrigeration charging system. The system and method are used to charge the refrigeration system of, e.g., an automotive vehicle.

Abstract: An automatic refrigerant handling apparatus has a compressor pump for withdrawing a refrigerant from an associated refrigeration system to be serviced, a condenser for liquefying the refrigerant and a storage vessel for storing the recovered refrigerant, the compressor pump also being capable of evacuating the refrigeration system to a first refrigeration system pressure. The apparatus has a connection jack for receiving a connector of an associated optional vacuum pump, the connector including a jumper which interconnects two terminals on the jack when the vacuum pump is connected so that the control circuitry of the apparatus can recognize the presence of the vacuum pump, whereupon the program routine of the control processor utilizes the vacuum pump instead of the compressor pump to draw a vacuum on the associated refrigeration system.

Abstract: A linearly moving external part of a multi-cylinder internal combustion engine is contacted with a hand-held contact tachometer for producing a waveform signal which, along with a signal responsive to the ignition of each cylinder, are applied to an engine analyzer processor for display of a single engine cycle of the waveform signal on the CRT oscilloscope of the engine analyzer. The variations and amplitude of the waveform signal correspond to speed variations of the moving part over an engine cycle to give an indication of the relative power contributions of the individual cylinders. Cylinder ignition markers and cylinder zone markers are respectively displayed at the top and bottom of the screen, respectively corresponding to the cylinders in their ignition order. Each cylinder zone marker is delayed a predetermined time from its corresponding cylinder ignition marker and indicates the time period during which the engine responds to the ignition event of the corresponding cylinder.

Abstract: A digital engine analyzer has an oscilloscope display and is controlled by microprocessors operating under menu-driven stored program control. The analyzer receives analog input signals from an engine being analyzed and calculates and display spark plug burn time information derived from a single analog input signal, the data being displayed in both numerical and bar graph form. The measured burn time is the time that the ignition voltage signal is above a predetermined threshold level which is greater than the amplitude of the ringing portion of the ignition voltage signal.

Abstract: A digital engine analyzer has an oscilloscope display and is controlled by microprocessors operating under menu-driven stored program control. The analyzer receives analog input signals from an engine being analyzed. The engine calculates and displays real-time cylinder time balance information by calculating for each cylinder the cylinder time period from the firing of that cylinder to the firing of the next cylinder, storing the cylinder time values for each cylinder for a number of successive engine cycles, averaging the time period values for each cylinder over that number of engine cycles, calculating an overall average of the cylinder averages, calculating the percentage difference between each cylinder average and the overall average and then displaying the percentage differences in both numerical and bar graph form along with the overall average value.

Abstract: A digital engine analyzer has an oscilloscope display and is controlled by microprocessors operating under menudriven stored program control. The analyzer receives analog input signals from an engine being analyzed. Peak capture circuitry permits the display of a full cylinder period of a waveform, even though it contains very high frequency portions, by selectively switching between normal and high resolution modes. The circuitry samples the analog waveform at a very high rate and selects samples for display at a much slower display rate. The circuitry captures and stores the highest magnitude sample in each cylinder cycle by storing each sample only if its magnitude exceeds that of the previously stored sample. In the normal mode, at each display clock pulse the most recent sample is selected for display, irrespective of its magnitude. In the high resolution mode the stored peak value is selected for display at each display clock pulse.

Abstract: A digital engine analyzer has an oscilloscope display and is controlled by microprocessors operating under menu-driven stored program control. The analyzer receives analog input signals from an engine being analyzed, digitizes the signals, captures the digital peak ignition voltage values for each cylinder and stores only these values for each cylinder over a number of successive engine cycles, and then simultaneously displays all the stored values for any one cylinder over a number of engine cycles to provide a historical display. Each peak value is stored twice and displayed twice to provide width to the value display and effectively produce a bar graph-type display.

Abstract: A digital engine analyzer has an oscilloscope display and is controlled by microprocessors operating under menu-driven stored program control. The analyzer receives analog input signals from an engine being analyzed. The analyzer is provided with a scanner interface, so that a scanner designed to read data from a vehicle on-board computer, can transfer this data to the analyzer for display on the analyzer oscilloscope. The analyzer processor, when operating in the scanner interface mode, operates under stored program control to reconfigure analyzer keyboard and soft key functions to duplicate scanner control functions, so that the scanner control functions can be effected from the analyzer.

Abstract: A microprocessor controlled digital engine analyzer recieved analog input signals from an engine being analyzed, engine parameter data entered via a keyboard, and function data, selecting one of several operating modes for the analyzer and which information is to be displayed, entered via the keyboard, and displays on a CRT screen the selected information such as cylinder firing order, RPM, Dwell, KV and DC volts, alphanumerically, information such as primary and secondary ignition and voltage, alternator and fuel injector information through the use of continuous waveform patterns, and additional information pertaining to Dwell, KV and Cylinder Shorting through the use of bar graphs.

Abstract: A distributorless ignition interface unit for use with an engine analyzer for analyzing an internal combustion engine includes a processing circuit which responds to analog signals representing true and wasted firings for the cylinders of the engine under test to determine the number of cylinders of the engine and the polarity of the firing of each cylinder and to then characterize the engine by determining the order of the true and wasted firing signals produced during an engine cycle and for producing a parade pattern of true or wasted secondary signals for application to the engine analyzer.

Abstract: A microprocessor controlled digital engine analyzer receives analog input signals from an engine being analyzed, engine parameter data entered via a keyboard, and function data, selecting one of several operating modes for the analyzer and which information is to be displayed, entered via the keyboard, and displays on a CRT screen the selected information such as cylinder firing order, RPM, Dwell, KV and DC volts, alphanumerically, information such as primary and secondary ignition and voltage, alternator and fuel injector information through the use of continuous waveform patterns, and additional information pertaining to Dwell, KV and Cylinder Shorting through the use of bar graphs.

Abstract: A microprocessor controlled digital engine analyzer receives analog input signals from an engine being analyzed, engine parameter data entered via a keyboard, and function data, selecting one of several operating modes for the analyzer and which information is to be displayed, entered via the keyboard, and displays on a CRT screen the selected information such as cylinder firing order,RPM, Dwell, KV and DC volts, alphanumerically, information such as primary and secondary ignition and voltage, alternator and fuel injector information through the use of continuous waveform patterns, and additional information pertaining to Dwell, KV and Cylinder Shorting through the use of bar graphs.

Abstract: A distributorless ignition interface unit for use with an engine analyzer for analyzing an internal combustion engine includes a processing circuit which responds to analog signals representing true and wasted firings for the cylinders of the engine under test to determine the number of cylinders of the engine and the polarity of the firing of each cylinder and to then characterize the engine by determining the order of the true and wasted firing signals produced during an engine cycle and for producing a parade pattern of true or wasted secondary signals for application to the engine analyzer.

Abstract: A microprocessor controlled digital engine analyzer receives analog input signals from an engine being analyzed, engine parameter data entered via a keyboard, and function data, selecting one of several operating modes for the analyzer and which information is to be displayed, entered via the keyboard, and displays on a CRT screen the selected information such as cylinder firing order, RPM, Dwell, KV and DC volts, alphanumerically, information such as primary and secondary ignition and voltage, alternator and fuel injector information through the use of continuous waveform patterns, and additional information pertaining to Dwell, KV and Cylinder Shorting through the use of bar graphs.

Abstract: A microprocessor controlled digital engine analyzer receives analog input signals from an engine being analyzed, engine parameter data entered via a keyboard, and function data, selecting one of several operating modes for the analyzer and which information is to be displayed, entered via the keyboard, and displays on a CRT screen the selected information such as cylinder firing order, RPM, Dwell, KV and DC volts, alphanumerically, information such as primary and secondary ignition and voltage, alternator and fuel injector information through the use of continuous waveform patterns, and additional information pertaining to Dwell, KV and Cylinder Shorting through the use of bar graphs.

Abstract: The apparatus comprises a combustion sensor to sense the combustion event in an engine, and a magnetic sensor to sense top dead center. Electrical signals from the sensors are converted to two trains of pulses which are applied to a microprocessor. Under the stored program, the microprocessor determines the time between pulses in one train and converts such time into engine speed in rpm. Also, the microprocessor determines degrees of rotation between corresponding pulses in the two trains. The offset angle, which is applied to a keyboard is subtracted from the degrees of rotation to provide the timing angle. The engine speed and timing angle appear in digital displays.