Apparatus for determining tonal characteristics of an object and method thereof

DETAILED DESCRIPTION OF THE DRAWINGS In the drawings, wherein like numerals represent like parts: FIG.
1 is a perspective view of a bell tester in accordance with the invention; FIG.
2 is a top view of the bell tester in accordance with the invention; FIG.
3 is a block diagram of the circuit for the bell tester of FIG.
1; FIGS.
4A and 4B are flow charts for the operation of the bell tester; FIGS.
5A-5C are flow charts of the average subroutine for a microprocessor incorporated in the circuit of FIG.
4; FIGS.
6A and 6B are circuit diagrams for the bell tester of FIG.
1; FIG.
7A is an example of a frequency distribution curve of a typical musical tone; FIG.
7B is an example of a typical frequency distribution curve of a bell; FIG.
8 is a waveform at output D of operational amplifier U8A of FIG.
4; FIGS.
9A-9C are waveform outputs at points A, B, and C, respectively, of the local oscillators of FIG.
4; FIG.
10 is a waveform at output E of AGC circuit 52 of FIG.
4.
FIG.
11 is a waveform at the output of the mixer circuit at point G of FIG.
4; FIGS.
12A-12C are waveforms at the outputs of the low-pass filters at points I, J, and K, respectively, of FIG.
4; FIGS.
13A-13C are waveforms at the outputs of the comparator circuit 73 at points L, M, and N, respectively, of FIG.
4; and FIG.
14 is the waveform output of microprocessor U2 to initiate the striking of the bell.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS Turning now to the drawings, FIGS.
1 and 2 depict a bell tester 10 for grading a bell 12 in accordance with the present invention.
A spindle 13 or the like is provided to secure the bell 12 in enclosure 14.
A removable cover 16 is provided to isolate the bell disposed in the enclosure 14 from ambient noise.
The cover 16 may be made of plastic, glass, or any sound insulating material, and is typically hemispherically-shaped.
A power switch 18 is provided for turning on and off the bell tester 10.
The type of bell, i.
e.
the note of the bell, is selected with a bell select switch 20