WO2002023373A1

WO2002023373A1 - Sound activated circuit

Info

Publication number: WO2002023373A1
Application number: PCT/US2000/024760
Authority: WO
Inventors: David Kung Tai Wai; Gordon Au; Ferenc Fekete
Original assignee: The Marketing Store Worldwide, L.P.
Priority date: 2000-09-11
Filing date: 2000-09-11
Publication date: 2002-03-21

Abstract

A novelty device (100) includes a sound-activated circuit. The sound-activated circuit includes an audio storage device (220) that stores a recorded message (310). A transducer (210) connected with the audio storage device (220) outputs the recorded message (310) when the circuit receives an external audio signal louder than a pre-determined level, such as a nearby handclap. The transducer (210) also operates to receive the external audio signal and convert the external audio signal to an input audio signal. A trigger circuit (230) connects with the transducer (210). When the transducer (210) receives the external audio signal, the trigger circuit (230) produces a trigger signal to activate the audio storage device (220) to output the recorded message (310).

Description

SOUND ACTIVATED CIRCUIT

FIELD OF THE INVENTION

This invention relates generally to voice playback circuitry, and more particularly to a sound activated voice playback circuit for a toy.

BACKGROUND

Many known toys include electronic circuitry. Some known toys include circuits that allow the toy to playback recorded messages, such as recorded voice data. Some of these toys use a microphone to detect sound to activate, and a speaker to project, the recorded voice of the circuit. Disadvantages of using a separate speaker and a microphone are the increased cost, size and total number of components of the circuit.

Other known circuitry uses a component that operates as both a microphone and a speaker. Such known circuitry typically requires a complicated structure and consumes a high amount of energy. Accordingly, there is a need for a system that utilizes a simplified circuit structure that consumes less energy and requires a low stand-by current capacity.

BRIEF SUMMARY

The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. By way of introduction, the preferred embodiment described below includes a system for providing voice playback with a simplified circuit structure.

In one aspect, a novelty device includes a sound-activated circuit. The sound-activated circuit includes an audio storage device that stores a recorded message. A transducer connected with the audio storage device outputs the recorded message when the circuit receives an external audio signal louder than a pre-determined level, such as a nearby handclap. The transducer also operates to receive the external audio signal and convert the external audio signal to an input audio signal. A trigger circuit connects via operational amplifiers with the transducer. When the transducer receives the external audio signal, the trigger circuit produces a trigger signal to activate the audio storage device to output the recorded message.

Further aspects and advantages of the invention are discussed below in conjunction with the preferred embodiments.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a sketch of an exemplary toy that includes sound activated circuitry in accordance with the invention.

FIG. 2 shows a schematic that illustrates an embodiment of the circuit in accordance with the invention.

FIG. 3 is a block diagram that illustrates an exemplary storage device of the circuit in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to the preferred embodiments, FIG. 1 illustrates an exemplary novelty device 100 that includes a sound-activated circuit described in FIG. 2.

The novelty device 100 includes toys, games and the like. The novelty device 100 shown is a dog playing a guitar, but other instruments, such as a drum, can be combined with the dog. Other characters, such as a cat, an alien or a famous celebrity, for example, could be used. The circuitry of the novelty device 100 picks up sounds, such as the nearby clapping of hands, and, in response to the sound, plays a recorded message or melody stored on the sound-activated circuit.

FIG. 2 shows a schematic that illustrates an embodiment of the sound- activated circuit 200. The sound activated circuit is preferably located inside the novelty device 100 (FIG. 1). The sound activated circuit 200 includes an audio storage device 220, a transducer 210 and a trigger circuit 230. The transducer detects an increase in an external audio signal 205 and causes the trigger circuit 230 to activate the audio storage device 220. A recorded message is then output from the audio storage device and played aloud through the transducer 210. The transducer 210 connects with the audio storage device 220 that preferably stores recorded messages 1 through N in blocks of digital audio output signals 310 as shown in FIG. 3. The audio storage device 220 is preferably a programmable read only memory (EPROM). Those skilled in the art will appreciate that other storage devices could be used such as electrically erasable programmable read only memory (EEPROMs) and random access memory (RAM).

The audio output signals 310 are output when trigger circuitry 230 produces a trigger signal 235. The trigger signal 235 occurs after the speaker 210 receives the external audio signal 205 that exceeds a pre-determined threshold, as described below. The trigger circuitry 230 includes an oscillator 250 that generates a clock pulse for a clock generator 255. The clock pulse preferably includes a frequency of one megahertz (MHz). Those skilled in the art will appreciate that the oscillator 250 may include an RC oscillator with an exemplary resistance R value of approximately sixty kilo-Ohms (kΩ). The clock generator generates a clock signal for control logic 260 and an address sequencer 265.

The control logic 260 includes inputs SI through SN that receive signals such as trigger signal 235. Other signals could be inputted to the control logic 260, such as a demonstration signal (not shown) for demonstrating the novelty device 100 to potential customers, and also can include a push button, photo sensor or infrared receiver. The control logic 260 connects with the address sequencer 265 to activate the address sequencer. The address sequencer 265 points to a starting address of the recorded messages 1 through N (see FIG. 3) to select one of the recorded messages. Preferably, the address sequencer 265 can alternately select the starting addresses of the recorded messages either sequentially or randomly. The outputted recorded messages may include music and a voice, and may also include other recorded messages, such as animal sounds. The control logic 260 can also connect to an output driver 270 that provides an output driver signal 272 to control a variety of driven devices, such as, for example, a light emitting diode (LED), a light bulb, a magnetic switch or a motor.

To output the recorded message, the sound-activated circuit 200 includes a digital-to-audio converter or pulse-width-modulator (PWM) 275 connected with the voice EPROM 220. The PWM 275 converts the audio output signal 310 from a digital signal to an audible digital signal. To achieve a higher-level output, the PWM 275 also modulates the audio output signal 310 with a high frequency to send the modulated signal to the dynamic speaker 210. The dynamic speaker 210 filters the high frequency signal and outputs the recorded message. To initiate the trigger signal 235, the dynamic speaker 210 receives the external audio signals 205 and converts the external audio signal 205 to an input audio signal 240. To avoid the outputted recorded message from initiating the trigger signal 235, the sound-activated circuit 200 includes a resistor R8 and a capacitor Cl which together filter high frequency sounds. The capacitor Cl blocks out direct current (DC) level signals and the resistor R8 provides a charge and discharge path for Cl and act as a current limit. Exemplary values for resistor R8 and capacitor Cl include ten kilo-Ohms and one-tenth micro-Farad.

The filtered input audio signal 245 is input to a first operational amplifier 280. Other components, such as transistors, can replace the operational amplifiers used herein. The first operational amplifier 280 amplifies the filtered audio input signal 245, preferably by a factor of two hundred, to produce amplified input signal 285. The gain is controlled using gain voltage Nl that is set with voltage source NDD and resistors R6 and R7. R3 is employed to provide negative feedback to prevent self-oscillation. An exemplary value for voltage source NDD includes 4.5 Volts. Exemplary values for resistors R6, R7 and R3 include two thousand two hundred kilo-Olims, eight hundred twenty kilo-Olims and two mega- Ohms respectively.

The amplified input signal 285 is then input to a second operational amplifier 290 that operates as a voltage comparator. The second operational amplifier 290 produces trigger signal 235 and provides sufficient current to drive the control logic 260 when the output of the first operational amplifier 280 includes a magnitude higher than a set voltage V2. Otherwise, the second operational amplifier 290 does not produce a trigger signal 235. N2 is determined, for example, using resistors R4 and R5 and voltage source NDD. When the trigger signal 235 goes high, the control logic 260 starts the address sequencer 265. The address sequencer 265 selects an output audio signal 310 containing a recorded message from the EPROM 220 The EPROM 220 sends the output audio signal 310 to the PWM 275, which in turn sends a modulated signal to the dynamic speaker 210 to output the recorded message

The preferred embodiments of the sound-activated circuit 200 operate on low standby current, for example, less than about twenty microamperes of current.

To stabilize the gam of the operational amplifiers, the sound-activated circuit preferably includes a current source 295. The current source 295 connects with the first and second operational amplifiers 280, 290. The current source 295 is powered by voltage source NDD and N3. N3 is determined, for example, using voltage source NDD and resistors Rl and R2. Exemplary values for Rl includes two thousand two hundred mega-Ohms and for R2 four hundred seventy kilo- Ohms.

In use, the novelty device 100 having the sound-activated circuit 200 is quiet until a loud sound is detected, such as a person nearby clapping their hands. Then a pre-recorded message will play. After the message is played, the novelty device 100 is then enabled to listen for another loud sound. Upon hearing another sound, another message, either in sequence or random order, will be played. The sound-activated circuit of the present invention has the advantages of using a low- cost, simplified structure that consumes less energy and requires low standby current capacity.

While the invention has been described above by reference to various embodiments, it will be understood that many changes and modifications can be made without departing from the scope of the invention. It is therefore intended that the foregoing detailed description be understood as an illustration of the presently preferred embodiments of the invention, and not as a definition of the invention. It is only the following claims, including all equivalents, that are intended to define the scope of this invention.

Claims

WE CLAIM:

1. A novelty device having a sound-activated circuit, the sound activated-circuit comprising: an audio storage device that stores a recorded message; a transducer connected with the audio storage device to output the recorded message when the circuit receives an external audio signal louder than a determined level, wherein the transducer also operates to receive the external audio signal and convert the external audio signal to an input audio signal; and a trigger circuit connected with the transducer, wherein, when the transducer receives the external audio signal, the trigger circuit produces a trigger signal to activate the audio storage device to output the recorded message.

2. The circuit according to claim 1, wherein the audio storage device comprises a digital device.

3. The circuit according to claim 2, wherein the audio storage device comprises a read-only-memory device.

4. The circuit according to claim X, wherein the external audio signal comprises an analog signal.

5. The circuit according to claim 1, wherein the trigger circuit comprises: a first operational amplifier to amplify the input audio signal to produce an amplified input signal; and a second operational amplifier connected with the amplified input signal, wherein the second operational amplifier compares the amplified input signal to a set voltage and produces the trigger signal when the amplified input signal exceeds the set voltage.

6. The circuit according to claim 5 further comprising: a control logic circuit connected with the trigger signal; and an address sequencer connected with the control logic circuit and the audio storage device, wherein commands the address sequencer to select the recorded message from the audio storage device.

7. The circuit according to claim 6 further comprising a pulse-width- modulator connected with the audio storage device, wherein the pulse-width- modulator converts the recorded message from a digital to an analog signal for output to the transducer.

8. The circuit according to claim 6 further comprising an output driver connected with the control logic, wherein the output driver drives a light emitting diode in accordance with the control logic.

9. The circuit according to claim 1 wherein the determined level of the external audio signal is at least as loud as the sound of a nearby ordinary handclap.

10. A novelty device that plays a recorded message when activated by a sound, the novelty device comprising: a sound-activated circuit, wherein the sound activated circuit comprises: an audio storage device that stores a recorded message; a transducer connected with the audio storage device to output the recorded message when the circuit receives an external audio signal louder than a determined level, wherein the transducer also operates to receive the external audio signal and convert the external audio signal to an input audio signal; and a trigger circuit connected with the transducer, wherein, when the transducer receives the external audio signal, the trigger circuit produces a trigger signal to activate the audio storage device to output the recorded message.

11. The novelty device according to claim 10, wherein the audio storage device comprises a digital device.

12. The novelty device according to claim 11, wherein the audio storage device comprises a read-only-memory device.

13. The novelty device according to claim 10, wherein the input audio signal comprises an analog signal.

14. The novelty device according to claim 10, wherein the trigger circuit comprises: a first operational amplifier to amplify a filtered input audio signal to produce an amplified input signal; and a second operational amplifier connected with the amplified input signal, wherein the second operational amplifier compares the amplified input signal to a set voltage and produces the trigger signal when the amplified input signal exceeds the set voltage.

15. The novelty device according to claim 14 further comprising: a control logic circuit connected with the trigger signal; and an address sequencer connected with the control logic circuit and the audio storage device, wherein commands the address sequencer to select the recorded message from the audio storage device.

16. The novelty device according to claim 15 further comprising a pulse-width-modulator connected with the audio storage device, wherein the pulse-width-modulator converts the recorded message from a digital to an analog signal for output to the transducer.

17. The novelty device according to claim 15 further comprising an output driver connected with the control logic, wherein the output driver drives a light emitting diode in accordance with the control logic.

18. The novelty device according to claim 10 wherein the determined level of the external audio signal is at least as loud as the sound of a nearby ordinary handclap.

19. A sound-activated circuit for a novelty device, the sound activated- circuit comprising: an audio storage device that stores a recorded message; a transducer connected with the audio storage device to output the recorded message when the circuit receives an external audio signal louder than a determined level, wherein the transducer also operates to receive the external audio signal and convert the external audio signal to an input audio signal; and an operational amplifier connected with the transducer, wherein the operational amplifier compares the input audio signal to a set voltage and produces a trigger signal when the input audio signal exceeds the set voltage, to output the recorded message.

20. The circuit according to claim 19 wherein the external audio signal comprises the sound of a handclap.