Parallel resonance

A transducer resonance where the current flow through the transducer is a relative minimum (i.e., the impedance is high).

Up to moderate loads, the transducer amplitude is relatively unaffected by the load. However, the transducer must be driven at relatively high voltages in order to obtain appreciable amplitude. Contrast with series resonance.

The frequency of parallel resonance will occur somewhat above series resonance.

Also called "open circuit resonance" because of the high impedance and because, if the piezoelectric ceramics are left open-circuited (i.e., not shorted together), then this is the resulting mechanical resonance of the transducer.

Also called "antiresonance" although this term should generally be avoided.