Dialed-phone-number-vocalizer


Posted on Dec 21, 2012

By vocalizing the numbers and symbols of its~eypad, the phone provides an audible confirmation that is useful to the blind. The serial-interface, 2 K-byte x 8-bit ROM (!C4) stores programmed sequences of instructions that are executed by the speech-processor chip IC2-manufactured by the General Instrument Corp. When you depress a key, tone-dialing chip ICl issues the corresponding number of pulses at its DP output.


Dialed-phone-number-vocalizer
Click here to download the full size of the above Circuit.

Counter IC5 totals the pulses, and IC6 latches the resulting 4-bit digital word. This word, converted to serial format by IC2, becomes an address that selects a block of memory within IC4.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

3A Dc-Dc Converter Needs No Heatsink Circuit
Motor Drivers
RGB LED Strip Circuit with Arduino
Solar Charge Controller connection with solar panel
LED Flasher Circuit Using 555 Timer IC Schematic Diagram
HV SUPPLY METERING & OVERVOLTAGE TRIP
Ultrasonic Dog Whistles
Non-Contact Proximity Switch Circuit
Universal AC Motor Speed Controller Kit
Human reaction speed test circuit
Simplified circuit bass attenuation



Top