Electronic clinical thermometer

Abstract

An electronic clinical thermometer has a first oscillator producing a first temperature oscillating output signal, a second oscillator producing a second temperature oscillating output signal whose frequency is dependent on a measured temperature body temperature, a first counter and a second counter and operative to provide a gate signal after a predetermined number count. A first memory temporarily stores the count content of the first counter in response to the gate signal, and a second memory stores the count content of the first memory. A digital magnitude comparator compares the count content of the first and second memories and produces a corresponding comparison signal indicative of whether the count content of the first memory is greater or not greater than the count content of the second memory. A flip-flop circuit responds to the comparison signal to produce a control signal for controlling a switching circuit in dependence on the comparison signal so as to selectively switch either the count content of the first memory or the count content of the second memory, whichever is greater, to a decoder ROM which decodes the count content and applies decoded digital signals to a driving circuit for driving a display. The display always shows the maximum value of the measured bodily temperature and thus provides error-free temperature measurements.