Acoustic-wave generating device

Patent metadata

Field	Value
Publication number	US-2023338989-A1
Application number	US-202318215327-A
Country	US
Kind code	A1
Filing date	Jun 28, 2023
Priority date	Mar 3, 2021
Publication date	Oct 26, 2023
Grant date	—

Abstract

An acoustic-wave generating device includes a drive circuit and a power auxiliary circuit. The drive circuit includes a capacitor chargeable via a direct-current power supply, and a drive switch to cause power to be supplied from the capacitor to an acoustic-wave source which produces heat through energization to generate acoustic waves. The power auxiliary circuit is operable to supplies power to the drive circuit to avoid a decrease of power supplied to the acoustic-wave source in an operation of generating a series of acoustic waves from the acoustic-wave source through switching of the drive switch.

First claim

What is claimed is:

1 . An acoustic-wave generating device comprising:
a drive circuit including a capacitor and a drive switch, the capacitor being chargeable via a direct-current power supply, and the drive switch being operable to cause power to be supplied from the capacitor to an acoustic-wave source which produces heat through energization to generate an acoustic wave; and a power auxiliary circuit to supply power to the drive circuit to avoid a decrease of power supplied to the acoustic-wave source in an operation of generating a series of acoustic waves from the acoustic-wave source through switching of the drive switch.

2 . The acoustic-wave generating device according to claim 1 , wherein the power auxiliary circuit is operable to supply power to the drive circuit in an OFF period of the drive switch.

3 . The acoustic-wave generating device according to claim 2 , wherein the power auxiliary circuit is operable to charge the capacitor in the OFF period of the drive switch.

4 . The acoustic-wave generating device according to claim 3 , wherein
the power auxiliary circuit includes:
an inductor electrically connected between the direct-current power supply and the capacitor; and
a charging switch electrically connected in parallel to a series circuit of the inductor and the direct-current power supply.

5 . The acoustic-wave generating device according to claim 4 , wherein
the power auxiliary circuit includes a diode; the diode is electrically connected, at an anode thereof, to the inductor; and the diode is electrically connected, at a cathode thereof, to the capacitor.

6 . The acoustic-wave generating device according to claim 4 , wherein the charging switch is ON during an ON period of the drive switch, and is switched off in the OFF period of the drive switch.

7 . The acoustic-wave generating device according to claim 6 , wherein the drive switch and the charging switch are switched on simultaneously.

8 . An acoustic-wave generating device comprising:
a drive circuit including a capacitor and a drive switch, the capacitor being chargeable via a direct-current power supply, the drive switch being operable to cause power to be supplied from the capacitor to an acoustic-wave source which produces heat through energization to generate an acoustic wave; and a power auxiliary circuit including an inductor and a charging switch and that supplies power to the drive circuit in an OFF period of the drive switch in an operation of generating a series of acoustic waves from the acoustic-wave source through switching of the drive switch, the inductor being electrically connected between the direct-current power supply and the capacitor, and the charging switch being electrically connected in parallel to a series circuit of the inductor and the direct-current power supply.

9 . The acoustic-wave generating device according to claim 8 , wherein
the power auxiliary circuit includes a diode; the diode is electrically connected, at an anode thereof, to the inductor; and the diode is electrically connected, at a cathode thereof, to the capacitor.

10 . The acoustic-wave generating device according to claim 8 , wherein the charging switch is ON during an ON period of the drive switch, and is switched off in the OFF period of the drive switch.

11 . The acoustic-wave generating device according to claim 10 , wherein the drive switch and the charging switch are switched on simultaneously.

12 . The acoustic-wave generating device according to claim 11 , wherein the charging switch is switched off after the drive switch is switched off.

13 . The acoustic-wave generating device according to claim 8 , wherein
Vc represents a voltage across both ends of the capacitor in a stationary state, Rth represents a resistance value of the acoustic-wave source, tAon represents a length of an ON period of the drive switch, imax represents a maximum of a current which is output from the inductor in an OFF period of the charging switch, and L represents a self-inductance of the inductor; and L satisfies an expression:

L
=

2
×
V
⁢

c
2

×
tAon

Rth
×
i

max
2

.

14 . The acoustic-wave generating device according to claim 8 , wherein
V represents a voltage of the direct-current power supply, tBon represents a length of an ON period of the charging switch, imax represents a maximum of a current which is output from the inductor in an OFF period of the charging switch, L represents a self-inductance of the inductor; and the direct-current power supply is set so as to satisfy an expression:

i
⁢
max

=

V
×
tBon

L

.

15 . The acoustic-wave generating device according to claim 1 , wherein the drive circuit includes an overcurrent protector electrically connected between the capacitor and the direct-current power supply.

16 . The acoustic-wave generating device according to claim 1 , wherein
the drive circuit includes a plurality of drive circuits; the power auxiliary circuit includes a plurality of power auxiliary circuits; the acoustic-wave generating device includes the plurality of drive circuits and the plurality of power auxiliary circuits corresponding to respective drive circuits; and the plurality of power auxiliary circuits supply power to the respective drive circuits so as to avoid a decrease of power supplied to the acoustic-wave source in an operation of generating a series of acoustic waves from the acoustic-wave source through alternate switching of the drive switches of the drive circuits.

17 . The acoustic-wave generating device according to claim 8 , wherein
the drive circuit includes a plurality of drive circuits; the power auxiliary circuit includes a plurality of power auxiliary circuits; the acoustic-wave generating device includes the plurality of drive circuits and the plurality of power auxiliary circuits corresponding to respective drive circuits; and each of the plurality of power auxiliary circuits supplies power to a corresponding one of the plurality of drive circuits in an OFF period of the drive switch of the corresponding drive circuit in an operation of generating a series of acoustic waves from the acoustic-wave source through alternate switching of the drive switches of the drive circuits.

18 . The acoustic-wave generating device according to claim 1 , wherein the power auxiliary circuit includes:
one or more auxiliary capacitors to be charged by one or more auxiliary direct-current power supplies correspondingly; and a selector

Assignees

• Murata Manufacturing Co

Inventors

• Sasaki Shinichi
• Asada Takaaki

Classifications

• B06B1/0215 Primary

  for generating pulses, e.g. bursts of oscillations, envelopes · CPC title

• B06B2201/40

  with testing, calibrating, safety devices, built-in protection, construction details · CPC title

• B06B2201/51

  Electrostatic transducer · CPC title

• H04R23/00

  Transducers other than those covered by groups H04R9/00 - H04R21/00 {(diaphragms for transducers of the distributed-mode type H04R7/045)} · CPC title

• H04R3/00

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title