Showing posts with label voice. Show all posts
Showing posts with label voice. Show all posts
Friday, 5 April 2013
Telephone call Voice Changer
Voice manipulation device specially intended for props, 9V Battery operation
Although this kind of voice effect can be obtained by means of some audio computer programs, a few correspondents required a stand-alone device, featuring microphone input and line or loudspeaker outputs. This design fulfills these requirements by means of a variable gain microphone preamplifier built around IC1A, a variable steep Wien-bridge pass-band filter centered at about 1KHz provided by IC1B and an audio amplifier chip (IC2) driving the loudspeaker.
Parts:P1______________10K Log. Potentiometer
R1,R10__________10K 1/4W Resistors
R2_______________1K 1/4W Resistor
R3______________50K 1/2W Trimmer Cermet or Carbon
R4,R6,R7,R14___100K 1/4W Resistors
R5______________47K 1/4W Resistor
R8______________68K 1/4W Resistor
R9_______________2K2 1/2W Trimmer Cermet or Carbon
R11_____________33K 1/4W Resistor
R12_____________18K 1/4W Resistor
R13_____________15K 1/4W Resistor
C1,C2,C3,C8,C9_100nF 63V Polyester Capacitors
C4______________10µF 25V Electrolytic Capacitor
C5_____________220nF 63V Polyester Capacitor (Optional, see Notes)
C6_______________4n7 63V Polyester Capacitor
C7______________10nF 63V Polyester Capacitor
C10____________220µF 25V Electrolytic Capacitor
IC1___________LM358 Low Power Dual Op-amp
IC2_________TDA7052 Audio power amplifier IC
MIC1__________Miniature electret microphone
SPKR______________8 Ohm Small Loudspeaker
SW1____________DPDT Toggle or Slide Switch
SW2,SW3________SPST Toggle or Slide Switches
J1____________6.3mm or 3mm Mono Jack socket
B1_______________9V PP3 Battery (See Notes) Clip for PP3 Battery
Notes:
- The pass-band filter can be bypassed by means of SW1A and B: in this case, a non-manipulated microphone signal will be directly available at the line or loudspeaker outputs after some amplification through IC1A.
- R3 sets the gain of the microphone preamp. Besides setting the microphone gain, this control can be of some utility in adding some amount of distortion to the signal, thus allowing a more realistic imitation of a telephone call voice.
- R9 is the steep control of the pass-band filter. It should be used with care, in order to avoid excessive ringing when filter steepness is approaching maximum value.
- P1 is the volume control and SW2 will switch off amplifier and loudspeaker if desired.
- C5 is optional: it will produce a further band reduction. Some people think the resulting effect is more realistic if this capacitor is added.
- If the use of an external, moving-coil microphone is required, R1 must be omitted, thus fitting a suitable input jack.
- This circuit was intended to be powered by a 9V PP3 battery, but any dc power supply in the 6 - 12V range can be used successfully.
Saturday, 30 March 2013
Make a Single Chip Programmable Voice Audio Recorder Circuit
The article explains a single chip circuit which can be used for recording short voice clips or any audio clip ranging from 20 to 60 seconds. The incorporated IC APR9600 is a programmable voice recorder chip which facilitates infinite number of recording/erase of audio files in it as per user preference.
The recording or storage of the audio can be done through an integrated electret mic or via any line out or RCA port of an audio reproducing device.
However since the IC is a low bit device does not support Hi-Fi recording rather low quality music.
The sampling rate or the frequency response is limited to just 8 kHz max thats pretty ordinary if we compare it with the specs of modern Hi-Fi equipment.
Nevertheless, the IC is a stand alone device which does not depend on any external circuits, just plug it in, and it starts recording whatever voice data is fed across its input pins. Moreover since the data can be erased and refreshed any number of times, the unit becomes completely programmable and a pretty useful gadget.
Image courtesy: http://www.datasheetcatalog.org/datasheet/aplus/APR9600.pdf
Circuit Description
The proposed circuit of a programmable single chip voice recorder/player utilizes the IC APR9600 as the main processor of the circuit.
Its a 28 pin IC which can be very easily and quickly configured for getting the required results by adding a handful of common passive electronic components.
All the pin outs of the IC are specified by their individual functions, and the components are accordingly attached with the respective pinouts.
For example pin#28 and pin#27 are assigned as the trigger inputs for initiating playback and recording functions.
Sliding the connected switch toward right initiates the playback action while toggling it toward left puts the IC in the recording mode.
The IC also has appropriate visual indication options which provide the user with instant information regarding the position of the circuit.
The LED at pin#8 indicates the end of a playback file session.
The LED at pin#10 stays illuminated for so long the audio is being played, indicating circuit "busy"
The LED at pin#22 indicates through rapid flashes regarding the playback or recording modes of the IC.
The input data is normally picked from the mic which is appropriately connected across the pins 17 and 18 of the IC.
When the slider switch is pushed toward the recording mode, any audio entering the mic gets stored inside the IC until the specified time elapses.
The sampling rate of the IC can be set as per the user preference. Lower sampling rates will provide longer recording/playback periods and vice versa.
Longer periods would also mean lower voice quality while shorter periods of recording spec will produce relatively better sound processing and storing.
The entire circuit operates with a 5 volt supply which can be acquire through a standard 7805 IC after rectification from a standard transformer bridge capacitor network.
The audio output may be derived across pin#14 and ground which must be terminated to an audio amplifier so that the data can be heard with proper volume.
The recording or storage of the audio can be done through an integrated electret mic or via any line out or RCA port of an audio reproducing device.
However since the IC is a low bit device does not support Hi-Fi recording rather low quality music.
The sampling rate or the frequency response is limited to just 8 kHz max thats pretty ordinary if we compare it with the specs of modern Hi-Fi equipment.
Nevertheless, the IC is a stand alone device which does not depend on any external circuits, just plug it in, and it starts recording whatever voice data is fed across its input pins. Moreover since the data can be erased and refreshed any number of times, the unit becomes completely programmable and a pretty useful gadget.
Circuit Description
The proposed circuit of a programmable single chip voice recorder/player utilizes the IC APR9600 as the main processor of the circuit.
Its a 28 pin IC which can be very easily and quickly configured for getting the required results by adding a handful of common passive electronic components.
All the pin outs of the IC are specified by their individual functions, and the components are accordingly attached with the respective pinouts.
For example pin#28 and pin#27 are assigned as the trigger inputs for initiating playback and recording functions.
Sliding the connected switch toward right initiates the playback action while toggling it toward left puts the IC in the recording mode.
The IC also has appropriate visual indication options which provide the user with instant information regarding the position of the circuit.
The LED at pin#8 indicates the end of a playback file session.
The LED at pin#10 stays illuminated for so long the audio is being played, indicating circuit "busy"
The LED at pin#22 indicates through rapid flashes regarding the playback or recording modes of the IC.
The input data is normally picked from the mic which is appropriately connected across the pins 17 and 18 of the IC.
When the slider switch is pushed toward the recording mode, any audio entering the mic gets stored inside the IC until the specified time elapses.
The sampling rate of the IC can be set as per the user preference. Lower sampling rates will provide longer recording/playback periods and vice versa.
Longer periods would also mean lower voice quality while shorter periods of recording spec will produce relatively better sound processing and storing.
The entire circuit operates with a 5 volt supply which can be acquire through a standard 7805 IC after rectification from a standard transformer bridge capacitor network.
The audio output may be derived across pin#14 and ground which must be terminated to an audio amplifier so that the data can be heard with proper volume.
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