Abstract: A fraud-resistant manually-fed reader-writer is especially suited for debit card use, in which a credit balance is read into the memory of the reader. When the card reaches the end of its insertion-reading movement, a validity indication encoded on the magnetic stripe of such card is automatically eradicated by energizing a de-gaussing coil. If, after effecting transactions which debit the memory, the card is removed by some artifice without re-writing it with a reduced balance, such removed card will lack a validity indication and hence be incapable of re-use. Provisions are made to time the re-writing and to avoid forfeiture of the balance if the card should be withdrawn too slowly or too rapidly.

Abstract: An adapter to permit a temperature measuring instrument ordinarily used with a thermistor temperature sensor to be used with a temperature probe of the thermocouple type. The adapter has an output for connection to the temperature measuring instrument and has circuitry for processing the signal from the thermocouple probe to produce at the adapter output a resistance which a thermistor sensor would generate at the same temperature. A temperature measuring instrument for efficient use of an electrical source has circuitry for processing a temperature related signal according to a sequence of operations to provide an electrical variable having a value which is a function of the temperature being measured. The sequence commences with connection of the electrical source to the processing circuitry. At the completion of the sequence a signal indicative of completion is produced. In responsive to the completion signal the electrical source is disconnected from the processing circuitry.