US 12,407,160 B2
Driving circuit for a piezoelectric ultrasonic transducer and ultrasonic transducer system
Mark Heinrich Ewald Rode, Lampertheim (DE)
Assigned to Pepperl+Fuchs SE, Mannheim (DE)
Filed by Pepperl+Fuchs SE, Mannheim (DE)
Filed on Mar. 29, 2023, as Appl. No. 18/128,031.
Claims priority of application No. 22168796 (EP), filed on Apr. 19, 2022.
Prior Publication US 2023/0330704 A1, Oct. 19, 2023
Int. Cl. H02H 3/20 (2006.01); H02M 3/156 (2006.01)
CPC H02H 3/20 (2013.01) [H02M 3/156 (2013.01); B06B 2201/40 (2013.01); B06B 2201/55 (2013.01)] 8 Claims
OG exemplary drawing
 
1. Driving circuit (2) for a piezoelectric ultrasonic transducer (4) in an ultrasonic transducer system (1), comprising:
a transformer (21) having at least one primary-side winding (22, 22′, 22″);
a switching unit having a semiconductor switch (24′, 24″) connected to the at least one primary-side winding (22, 22′, 22″) via a switched connection (A′, A″); and
a control unit (5) which is configured to alternately apply an operating voltage (UB) to the at least one primary-side winding (22, 22′, 22″) or to disconnect it therefrom,
a protection circuit (25) which is electrically coupled to the switched connection (A′, A″) and which has a Zener diode (ZD1) which limits a switch-off voltage at the switched connection (A′, A″) in terms of magnitude to a limiting voltage (UG) which corresponds to at least twice the operating voltage,
wherein the transformer (21) has two primary-side windings (22, 22′, 22″) which are being alternately connected to and disconnected from the operating voltage (UB), so that the operating voltage (UB) is constantly applied to one of the primary-side windings (22, 22′, 22″), and
wherein the corresponding switched connections (A′, A″) of the primary-side windings (22, 22′, 22″) are connected to the protection circuit (25), in particular via a respective diode (D1, D2).