having a single resonator (crystal tuning forks H03H9/21)

Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators > Constructional features of resonators consisting of piezoelectric or electrostrictive material > having a single resonator

Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators (electro-acoustic transducers such as loudspeakers, microphones or gramophone pick-ups H04R; piezoelectric, electrostrictive or magnetostrictive devices with mechanical input or output, e.g. actuators or sensors, H10N30/00, H10N35/00) > Constructional features of resonators consisting of piezoelectric or electrostrictive material (H03H9/25 takes precedence) > having a single resonator (crystal tuning forks H03H9/21)