Electronic clinical thermometer with power shut-off at maximum temperature

Claim 1

An electronic clinical thermometer comprising: (a) a thermometric oscillator means for producing output pulses having an oscillation frequency which varies in accordance with a temperature desired to be measured; (b) a thermometric counter means connected to said thermometric oscillator means for counting said output pulses, the frequency of said output pulses proportional to the temperature to be measured; (c) a maximum value memory circuit means connected to said thermometric counter means for storing a maximum count value of said counter means corresponding to a maximum temperature; (d) a comparison circuit means for comparing the maximum count value stored in the maximum value memory circuit means with the count value from the thermometric counter means and for producing a reset signal when said thermometer counter count value is greater than said maximum count value; (e) a reference oscillator generating a plurality of reference pulses; (f) a clock counter means connected to said reference oscillator for counting clock pulses from said reference oscillator and connected to receive said reset signal for resetting the count of said clock pulses, said clock counter producing an overflow signal when no reset signal is received after a predetermined time from said comparison circuit; and (g) said thermometric oscillator responsive to said overflow signal from said clock counter means for inhibiting production of said output pulses from said thermometric oscillator means, whereby energy is conserved by terminating production of said thermometric oscillator output pulses when said maximum temperature is stored in said maximum value memory circuit means.