Electronic sound generating toy

The electronic device uses domino-shaped sound elements in combination with a support track to generate audible sounds or musical notes. The sound elements are placed in indentations on a support track in a selected sequence corresponding to the sequence of musical notes in a song to be played. Each of the sound elements corresponds to a single sound or musical note. When the sound elements are toppled in a domino-type manner, the notes are played in the selected sequence. Each of the sound elements has one or more magnetic elements in its bottom surface. The movement of the magnetic element away from associated Hall Effect sensors in the support track during toppling of the sound elements is used to trigger a decoding circuit. The decoding circuit determines the note pattern and generates the associated sound through an output speaker. A timbre sound element may also be used to select the timbre or other tonal characteristics of the output sounds.

BACKGROUND OF THE INVENTION 
This invention relates to electronic toys of the type which generate 
audible sounds, musical notes, tones and songs. 
Toys are known which generate a preselected series of sounds or musical 
notes once the device is activated. Although such devices provide some 
amusement, they generally do not instruct the child in musical 
composition, nor are they changeable by the child. 
Other musical toys such as toy pianos or xylophones are known which 
generate musical sounds. However, the child must typically learn the song 
and must strike the keys in a pre-selected manner corresponding to the 
song in order to generate the song. The striking of the keys at the 
appropriate time may be beyond the skill of young children. 
Therefore, it is desirable to provide a musical toy that teaches children 
some basics of music, which allows many different songs to be played, and 
which is still within the skill of young children. 
SUMMARY OF THE INVENTION 
The sound generating device includes a support member having a plurality of 
successive sections, each of the sections having an indentation that is 
adapted to receive a domino-shaped sound element. The sound elements are 
placed in the indentations and are spaced on the support member. Each of 
the sound elements is associated with a specific sound or musical note. 
The distance between successive indentations is less than the length of 
each sound element, so that the sound elements may be toppled in a domino 
manner to play a succession of sounds or a musical song. 
Each of the indentations in the support member has associated therewith a 
plurality of sensors that sense the movement of the sound element away 
from the particular indentation. In a preferred embodiment, the bottom of 
each sound element contains a plurality of magnetic components which 
uniquely identify the sound element with a particular musical note. Hall 
Effect sensors are disposed near the surface of the indentation, and sense 
the movement of the sound element away from the indentation when the sound 
element is toppled. 
Also in a preferred embodiment, the support member comprises a linear track 
which is connectable to one or more other similarly-shaped support 
members. In this way, musical songs comprising many notes may be played by 
toppling the domino-shaped sound elements. 
The sound generating device also includes a sound generating means for 
audibly generating the sounds associated with the sound elements. In one 
embodiment, the sound generating means includes a means for receiving an 
input signal from the sensing means when the sensing means determines that 
the sound elements have been moved away from the indentations in the 
support element, a means for thereafter generating a signal corresponding 
to the primary frequency of the sound, and a speaker that receives the 
generated signal and that outputs the first sound. In one embodiment, the 
signal generating means includes a plurality of oscillators that output a 
plurality of distinct frequency signals, and an analog selector that 
selects the frequency signal from the plurality of frequency signals which 
corresponds with the primary frequency of the selected sound. 
In another embodiment, the signal generating means includes a 
microprocessor that generates a rectangular wave signal at the primary 
frequency, and a wave shaping means for converting the rectangular wave 
signal into a substantially sinusoidal waveform. 
The preferred embodiment also includes a removable timbre element that is 
associated with a selected timbre of the sounds or musical notes. 
The invention is particularly suitable for children because it is easy to 
use and does not require a great deal of manual dexterity to generate a 
musical song. Also, the invention teaches children about musical 
composition since each of the removable sound elements is preferably 
associated with a particular musical note, and must be placed in the 
proper sequence to generate the song. The invention also demonstrates to 
children that the same musical note may have different sounds, depending 
upon the selected timbre. 
It is therefore a feature and advantage of the present invention to provide 
a musical toy which also serves as a music instructional device. 
It is another feature and advantage of the present invention to provide a 
durable, self-contained musical toy that may play a wide variety of 
user-selected songs with no musical training.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In a preferred embodiment of the present invention, the electronic device 
has a plurality of spaced domino-shaped sound elements placed in 
indentations in one or more linear support tracks. Each sound element 
corresponds to a single sound or musical The sequential placement of the 
sound elements corresponds to the notes in a song. Each of the sound 
elements may be marked with the note to which it corresponds, or may be 
color-coded to match the color code on sheet music. 
It is to be understood, however, that the present invention may be used to 
generate other audible sounds besides musical notes and musical songs. For 
example, particular sound elements could be used to mimic animal sounds, 
the sounds of shooting guns, jet engines, or virtually any other 
electronically reproducible sound. 
The sound elements as described below are totally removable from their 
support element or track. However, it is within the scope of the present 
invention to have the sound elements permanently hinged to the sound track 
so that they are readily replaced in an upright position after they have 
been toppled. Of course, other arrangements are also within the scope of 
the present invention, such as having the sound elements removably 
engagable with a hinged bracket. 
Referring to the preferred embodiment depicted in FIG. 1, a plurality of 
sound elements 10, 12 and 14 are disposed in respective indentations or 
recesses 16, 18 and 20 of a support element 22. Each of the sound elements 
preferably corresponds to a particular musical note or other audible 
sound. In FIG. 1, sound element 10 corresponds to an E note, sound element 
12 corresponds to an F note, and sound element 14 corresponds to an A 
note. 
Also placed in support element 22 is a timbre sound element 24 that is 
received in an indentation or recess 26 of support element 22. Timbre 
element 24 determines the tonal characteristics of sound elements 10 
through 14. Where the sound elements are musical notes, the timbre element 
corresponds to the sound of a particular musical instrument, such as a 
horn 28. If the sound elements correspond to audible sounds other than 
musical notes, timbre element 24 may determine the pitch, volume, 
duration, or other characteristic of the individual sound elements. 
Support element 22 encloses all of the electronics of the electronic 
device. Specifically, linear track 22a encloses the sensing circuitry 
described below, and section 22b encloses the sound generating circuitry 
as well as an output speaker 30. 
The bottom surface of each sound element has a plurality of magnets 
disposed therein. In FIG. 1, each sound element has 1 to 5 magnets. Magnet 
32a of sound element 10 is the first to be sensed by the sensing circuit 
associated with sound element 10. Strobe magnet 32a informs the sensor 
that a reading should be taken to determine whether the sound element is 
being moved and the particular note associated therewith. Each of the 
sound elements has a strobe magnet. 
Other magnetic elements 32b through 32e are positioned so that they have 
corresponding Hall Effect sensors associated therewith. Magnets 32b 
through 32e determine the particular note or audible sound that is to be 
played by sound element 10. The presence or absence of a magnet in the 
positions of magnets 32b through 32e together create a four bit binary 
word. If a magnet is present in a particular position, the corresponding 
bit of the binary word becomes a "1" by using inverter logic. If a magnet 
is not present in the particular position, the bit in the binary word 
becomes a "0". In the example depicted in FIG. 1, the binary word 
corresponding to sound element 10 is 1111, or 16. Thus, the musical note E 
corresponds to the number 16. In this way, two full octaves of a musical 
scale, consisting of 16 notes, may be represented in the song. Of course, 
rests, quarter notes, half notes, etc. may all be encoded in this manner. 
To play a complete musical song, it is desirable to interconnect a 
plurality of tracks 22 together in a linear fashion. The first sound 
element 10 is then toppled to cause the song to be played as a result of 
the domino-type toppling of the other sound elements. FIG. 2 depicts the 
connection of a plurality of support elements 22 in an end-to-end fashion. 
Track 22a is connected to track 22c by a seven pin plug-type connector 34 
that is received in a corresponding seven pin receptacle-type connector 36 
on track 22c. A seven pin connector is used since the bus has seven lines 
that interconnect each of the sensor circuits: four of the lines 
correspond to the four bits of the digital word; one line corresponds to 
the strobe signal; one line is the ground; and the last line is the power 
input Similarly, track 22c is connected by a seven pin plug-type connector 
38 to a corresponding seven pin receptacle-type connector 40 disposed on 
track 22d. 
As discussed above, each of the sound elements has a sensor that senses the 
movement of the sound element away from support element 22. These sensor 
circuits are all identical. Eight such sensor circuits are depicted in 
FIGS. 3A through 3H. In FIGS. 3A through 3H, each sensor circuit includes 
Hall Effect sensors 42, 44, 46, 48 and 50. Sensors 42 correspond to the 
strobe sensor. Sensors 44 correspond to the least significant bit of the 
four bit binary word. Sensors 50 correspond to the most significant bit 
("8") in the four bit binary word. Resistors 52 and capacitors 54 together 
form an RC timing circuit that hold the output signal from Hall Effect 
sensors 42 through 50 for a short time after the associated sound element 
actually falls. Capacitors 54 begin charging after the sound element 
falls, thereby retaining the output signal until the strobe is completed. 
The RC network preferably has a 4.7 millisecond time constant. The RC 
circuit for strobe sensor 42 has a shorter time constant. 
Each of the Hall Effect sensors is connected to its respective Schmitt 
trigger inverter 56, 58, 60, 62, and 64. The output of inverter 56 is 
connected via a capacitor 64 to the input of Schmitt trigger inverter 68. 
The output of inverter 68 is connected as an input to each of AND gates 
70, 72, 74, and 76. The other input to AND gates 70, 72, 74 and 76 is 
connected to the output of inverters 58, 60, 62 and 64 respectively. The 
output of AND gates 70, 72, 74 and 76 are connected through resistors 78, 
80, 82, and 84 to the bases of transistor switches 88, 90, 92 and 94. 
Each of the sensors in FIG. 3A through 3H operates in the following manner. 
Hall Effect sensors 42 through 50 are in their static ON state whenever a 
magnet corresponding thereto has been sensed. However, no signal is output 
on bus lines 96, 98, 100, 102 and 104 until the circuits are enabled by a 
strobe pulse. 
When the movement of a sound element is sensed, strobes sensor 42 is turned 
OFF, and its associated capacitor charges. At the same time, any of the 
other sensors which had been turned ON due to the presence of an 
associated magnet are also turned OFF, and their associated capacitor is 
also charged. When the capacitor associated with the strobe sensor gets 
charged, a logical "1" signal is applied to the input of inverter 56, 
which is inverted to a logical "0" at its output. This output is fed to 
the AC coupled circuit, consisting of diode 106, capacitor 66, resistor 
52b and inverter 68. Inverter 68 outputs a logical "1" signal while 
capacitor 66, associated with strobe inverter 36, is charging. The 
momentary high output from inverter 68 is applied as one of the inputs to 
AND gates 70 through 76. 
At the same time, the inputs to inverters 58 through 64 remain low during 
the charging of their associated RC time constant circuit after their 
sensors 44 through 50 are turned OFF. These logical "0" signals are 
inverted by inverters 58 through 64 so that a logical "1" is applied to 
one or more of AND gates 70 through 76. With the presence of the strobe 
signal, the output of the AND gates corresponding to the selected note go 
high, thereby turning ON transistor switches 86 through 94. When the 
transistors are turned ON, signals are applied to their bus lines. As 
indicated above, each of the strobe outputs is connected to a single bus 
line. Also, each of the other bits of the digital word is connected to the 
sensors of the same bit in each of the other sensor circuits. That is, 
each of the least significant bits is connected together via the same bus 
line, each of the most significant bits is connected via the same bus 
line, and so on. 
FIGS. 4A through 4G are timing diagrams corresponding to the circuits of 
FIGS. 3A through 3H. In FIGS. 4A through 4G, the signal in FIG. 4A 
corresponds to the output of strobe sensor 42. The signal in FIG. 4B 
corresponds to the output of sensors 44, 46, 48 and 50. The signal in FIG. 
4C corresponds to the output of inverter 56. The signal in FIG. 4D 
corresponds to the signal input to inverter 68 after the sound element has 
been toppled. The signal in FIG. 4E corresponds to the output of inverter 
68. The signal in FIG. 4F corresponds to the output of inverters 58, 60, 
62 and 64. Finally, the signal in FIG. 4G corresponds to the signal on 
strobe bus 96 and each of buses 98-104 where a magnet was present. 
FIG. 5 is a schematic diagram of an analog sound generating circuit that 
may be used in the present invention, and particularly with the sensing 
circuits of FIG. 3A through 3H. For the sake of simplicity, however, the 
circuit in FIG. 5 has been limited to a circuit that will only generate 
eight different audible sounds or musical notes. It is well within the 
scope of the ordinary person skilled in the art to expand the circuit of 
FIG. 5 to permit the generation of 16 or more audible sounds. 
In FIG. 5, the strobe signal present on bus 96 latches the note pattern 
present on buses 98, 100 and 102 into a set of D-type latches 110, 112, 
and 114 respectively. Each of the note pattern signals is first inverted 
via inverters 116, 118, and 120 respectively. The inverted strobe signal 
also triggers a 1-shot timer 122, which instructs an analog 1 of 8 
selector 124 as to the length of time that each sound is to be passed 
through to the speaker. 
Selector chip 124 has connected thereto eight oscillator circuits 128. Each 
of the oscillator circuits includes a Schmitt trigger inverter 130, a 
capacitor 132, and resistors 134 and 136. Each of oscillators 128 outputs 
a different frequency, corresponding to a primary frequency of an audible 
sound or musical note. Selector 124, in response to the input note 
pattern, selects one of the oscillating frequencies and outputs a signal 
corresponding thereto at pin 3. This output signal is inverted by inverter 
138, which drives a pair of transistors 140 and 142 connected in a 
push-pull manner. Transistors 140 and 142 in turn drive output speaker 144 
through a capacitor 146 to produce the audible sounds. 
FIG. 6 depicts an alternate, microprocessor-based circuit for generating 
the audible sounds. In FIG. 6, the sounds are sent via buses 44, 46, 48 
and 50 as inputs to inverters 148, 150, 152 and 154 respectively. The 
inverted signals are applied to pins 1 through 4 of microprocessor 156. 
The strobe signal is sent by bus 42 to the input of an inverter 158, whose 
output is connected as an input to inverter 160. The output of inverter 
160 is applied to the interrupt input (pin 12) of microprocessor 156. 
Hall Effect sensors 162, 164, 166 and 168 cooperate with magnets on the 
bottom of the timbre sound element to select the timbre, or tonal 
characteristics of the output audible sounds. The outputs of sensors 162 
through 168 are applied to pins 5 through 8 respectively of microprocessor 
156. Hall Effect sensor 170 senses the presence of a magnet on the bottom 
of a power enable block element that may be placed on the support track. 
The power enable block element avoids the need for a separate Power On 
switch. 
Circuit 172 resets microprocessor 156 based upon a voltage trigger point in 
the event that the voltage output of a battery power supply decreases to a 
threshold level, such as 4.5 VDC. Circuit 172 automatically holds 
microprocessor 156 in the reset condition, to prevent microprocessor 156 
from operating in the event that inadequate power exists. Circuit 172 
includes diodes 174, 176 and 178, capacitors 180 and 182, resistors 184 
through 204, operational amplifiers 206 and 208, and a switch 210. 
Based upon the input sound, microprocessor 156 outputs a rectangular 
waveform corresponding to the selected frequency at pin 21. A pair of 
inverters 212 and 214 control a pair of transistors 216 and 218. A second 
pair of inverters 220 and 222 control a pair of transistor switches 224 
and 226. The outputs of the transistor pairs are complementary square 
waves. Capacitors 228 and 230 filter the square waves to make them 
substantially sinusoidal. The two complementary waveforms are applied to 
the inputs of a speaker 232, and have the effect of doubling the volume 
output of speaker 232. 
FIG. 7 is a flow chart of the software used to operate microprocessor 156. 
In FIG. 7, the program begins at Step 234 by powering up or resetting the 
microprocessor. At Step 236, a determination is made whether the voltage 
supplied to the microprocessor is greater than the threshold voltage of 
4.5 volts. If not, the microprocessor resets at Step 234, as discussed 
above in connection with FIG. 6. 
If the answer is YES at Step 236, a determination is made at Step 238 
whether the timbre sound element is present. If the timbre element is not 
present, the program loops back to Step 234. If the timbre element is 
present, the electronic device is set up at Step 240 based upon the 
selected timbre. At Step 242, a determination is made whether the strobe 
signal has been received. If the strobe signal has not been received, the 
program loops back to determine whether the timbre element is present. If 
a strobe signal has been received, the binary sound pattern is read at 
Step 244 and the appropriate sound is output. The program then returns to 
Start. 
Although several embodiments of the present invention have been shown and 
described, other embodiments will be apparent to those skilled in the art 
and are within the intended scope of the present invention. Therefore, the 
invention is to be limited only by the following claims.