Device and method for filtering the resonance peak in a circuit for supplying at least one loud speaker upstream of the latter

Patent metadata

Field	Value
Publication number	US-10271139-B2
Application number	US-201515127851-A
Country	US
Kind code	B2
Filing date	Mar 3, 2015
Priority date	Mar 5, 2014
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

The present invention relates to an acoustic signal supply circuit of at least one loudspeaker (HP), this circuit comprising a filtering device of the resonance peak occurring at a given frequency of the supply current, characterized in that the filtering device of the peak is incorporated in a first branch bypassing the intermediate circuit between at least two converters (A, A0), this filtering device being purely electrical in the form of an impedance (Z3) connected, on the one hand, at a point on the intermediate circuit and, on the other hand, to a ground instrumentation, the impedance being called RLC (Z3) for comprising at least one first resistor (R3), at least one first capacitor (C3) and at least one first inductor (L3) arranged in series, the parameters of the first resistor (R3), the first capacitor (C3) and the first inductor (L3) being predetermined as a function of the resonance peak to be filtered.

First claim

The invention claimed is:

1. An acoustic signal supply circuit of at least one loudspeaker, said circuit comprising a filtering device of a resonance peak occurring at a given frequency of a supply current of said at least one loudspeaker and at least two non-inverting converters arranged in series upstream of said at least one loudspeaker, each of the two converters having a positive supply terminal and a negative supply terminal and an output, the most upstream of the two converters having its positive supply terminal connected to the circuit input supply while its output is connected via an intermediate circuit to the positive supply terminal of the second converter, the output of the second converter being connected to said at least one loudspeaker, characterized in that the filtering device of the resonance peak of said at least one loudspeaker is incorporated in a first branch bypassing the intermediate circuit between said at least two converters, this filtering device being purely electrical and being an impedance connected, firstly, to a point in the intermediate circuit and, secondly, to a ground instrumentation, the impedance being called RLC for comprising at least one first resistor, at least one first capacitor and at least one first inductor arranged in series, a plurality of parameters of the first resistor, the first capacitor and the first inductor being predetermined as a function of the resonance peak to be filtered of said at least one loudspeaker;
wherein the first inductor is virtual in being formed of two non-inverting auxiliary converters arranged in series, each of the two auxiliary converters having a positive supply terminal and a negative supply terminal and an output, the most upstream of the two auxiliary converters having its positive supply terminal connected to the output of the first capacitor whereas the output of this most upstream auxiliary converter is connected by a first auxiliary intermediate circuit to the positive supply terminal of the second auxiliary converter, the first intermediate auxiliary circuit comprising an auxiliary capacitor and being connected in bypass to a first auxiliary instrumentation ground circuit having a first auxiliary resistor, the output of the second auxiliary converter being connected to the first auxiliary converter by a second auxiliary circuit including a second auxiliary resistor, each auxiliary converter having its own feedback loop connecting its output to its negative supply terminal;
wherein a second capacitor is arranged in a second branch bypassing the intermediate circuit between said at least two converters, this second capacitor being associated with a second resistor, the parameters of the second resistor and the second capacitor being predetermined to reduce the high frequency signals;
wherein the intermediate circuit between the two non-inverting converters comprises a third resistor arranged between the output of the most upstream non-inverting converter and the first bypass branch of the intermediate circuit incorporating the filtering device.

2. The circuit of claim 1 , wherein the first virtual inductor is equal to the product of the first and second auxiliary resistors and the auxiliary capacitor.

3. The circuit of claim 2 , wherein the first resistor and the second auxiliary resistor are deducted from each other in a total resistance according to the equation:
R 3 =R 03 −R A .

4. The circuit of claim 1 , wherein for a 197 Hz resonance peak frequency, the value of said at least one first resistor is equal to 0, the values of said at least one first capacitor and said at least one first inductor are respectively equal to 0.29 pF and 2.28 H, the values of the first auxiliary resistor and the second auxiliary resistor being respectively equal to 1,200Ω and 400Ω, the value of the third resistor being 3,000Ω.

5. The circuit of claim 1 , wherein each non-inverting converter has its own feedback loop connecting its output to its negative supply terminal, each of the feedback loops being mounted, for the most upstream converter, bypassing the intermediate circuit between the two non-inverting converters and, for the most downstream converter, bypassing an instrumentation ground circuit arranged after said at least one loudspeaker, the instrumentation ground circuit comprising a fourth resistor.

6. A method of supply control of the acoustic signal power supply of at least one loudspeaker, the power supply incorporating a filtering device of the resonance peak according to claim 1 , in which method a correction step of the resonance peak is performed by the filtering device, this step taking place upstream of said at least one loudspeaker.

7. The method of claim 6 , wherein the overall resonance factor of the loudspeaker and of the filtering device is set to a Butterworth filter.

8. The method of claim 6 , wherein, when said at least one loudspeaker includes a diaphragm, filtering of the resonance peak is performed simultaneously to a reduction in the sound level in the highest frequencies in the direction of the perpendicular axis of the diaphragm of said at least one loudspeaker.

9. The method of claim 6 , wherein temperature variations of said at least one loudspeaker are taken into account by the filtering device by variation matching the impedance parameters of said device.

Assignees

• Whylot Sas
• Univ Maine
• Centre Nat Rech Scient

Inventors

• Gaviot Etienne
• Erza Mehran
• Polet Frederìc
• Camberlain Lionel
• Ravaud Romain

Classifications

• H04R3/08 Primary

  of electromagnetic transducers · CPC title