Tuning device with battery condition display

Claim 1

A tuning device comprising: a battery constituting a source of operating power for the device; averaging means connected to said battery for producing a battery voltage signal representative of the average value of the battery voltage over a selected time interval; a tuning circuit for computing data identifying a note to be tuned; a reference sound generating circuit for generating a signal representing a reference sound; means including a speaker connected to said reference sound generating circuit for producing an audible reference sound corresponding to that represented by the reference sound signal; switch means operable for selectively providing an indication of one of a tuning mode in which a tuning operation is performed and a reference sound producing mode in which a reference sound is produced, and for providing a designation of the reference sound to be produced by said reference sound generating circuit; control means connected to said switch means, said averaging means, said tuning circuit and said reference sound generating circuit, said control means being operative for placing said device in a selected one of the tuning mode and the reference sound producing mode in response to the mode indication provided by said switch means, for controlling and receiving data from said tuning circuit when said device is in the tuning mode, and for activating said reference sound generating circuit to generate a reference sound signal based on the designation provided by said switch means when said device is in the reference sound producing mode; and display means connected to said control means for providing a display indicating the current state of charge of said battery when said device is in the reference sound producing mode, in response to the battery voltage signal produced by said averaging means.