Abstract: Multiple heaters are calibrated and controlled by a microcomputer, and a multiplexer for this system. The heaters are sequentially sampled and resistance calculated from voltage and current measurements. The operator enters a temperature for the calculated resistance to establish a calibrated resistance value. During run, the computer energizes and samples each heater to calculate its resistance. The calculated resistance if divided by the calibrated resistance to determine a resistance ratio. A look-up table is stored in the computer having resistance ratios for corresponding temperature. The computer compares the calculated ratio to that of the look-up table to determine actual heater temperatures. Based upon heater temperatures, the computer controls energization of the heaters until set points are achieved. Negative temperature coefficient and positive temperature coefficient transistors and semiconductors can be utilized.

Abstract: Multiple heaters are calibrated and controlled by a microcomputer, and a multiplexer for this system. The heaters are sequentially sampled and resistance calculated from voltage and current measurements. The operator enters a temperature for the calculated resistance to establish a calibrated resistance value. During run, the computer energizes and samples each heater to calculate its resistance. The calculated resistance if divided by the calibrated resistance to determine a resistance ratio. A look-up table is stored in the computer having resistance ratios for corresponding temperature. The computer compares the calculated ratio to that of the look-up table to determine actual heater temperatures. Based upon heater temperatures, the computer controls energization of the heaters until set points are achieved. Negative temperature coefficient and positive temperature coefficient transistors and semiconductors can be utilized.

Abstract: Multiple heaters are calibrated and controlled by a microcomputer, and a multiplexer of this system. The heaters are sequentially sampled and resistance calculated from voltage and current measurements. The operator enters a temperature for the calculated resistance to establish a calibrated resistance value. During run, the computer energizes and samples each heater to calculate its resistance. The calculated resistance is divided by the calibrated resistance to determine a resistance ratio. A look-up table is stored in the computer having resistance ratios for corresponding temperatures. The computer compares the calculated ratio to that of the look-up table to determine actual heater temperatures. Based upon heater temperatures, the computer controls energization of the heaters until set points are achieved.

Abstract: The disclosure describes a computer-aided instructional system for teaching a student to trouble-shoot a piece of equipment, such as a radio receiver, with a tester, such as a volt-ohm meter (VOM). In order to achieve this result, the receiver and VOM are simulated by non-operating components which are controlled by the computer to respond as if they were fully operative and functioning devices. A computer-operated display presents instructions to the student and monitors the student's responsive use of the simulated receiver and VOM. Additional instructions are selected for display depending on the nature of the student's responses. In this way, the student learns to analyze the equipment by proper use of the tester.