Low-Power Touch-Tone Decoder
Description: This decoder will respond to a preselected 4-digit DTMF number. IC7 is a Radio Shack IC device (part #276-1303). The logic is all CMOS. The digits are selected by SW1 and SW2, a pair of 8-position DIP switches.
The described circuit employs a DTMF (Dual-Tone Multi-Frequency) decoder that is designed to recognize a specific 4-digit number. The core component, IC7, is a CMOS-based integrated circuit from Radio Shack, identified by the part number 276-1303. This IC is capable of interpreting the audio tones generated by a DTMF keypad, converting them into digital signals that correspond to the pressed keys.
User interaction is facilitated through two 8-position DIP switches, labeled SW1 and SW2. These switches allow for the selection of the desired DTMF digits by configuring the binary inputs that the decoder IC reads. Each switch can be set to either a high or low state, representing binary values that correspond to the DTMF digits 0-9 and the additional symbols such as *, #, A, B, C, and D.
The overall logic of the circuit is implemented using CMOS technology, which is known for its low power consumption and high noise immunity. This makes the circuit suitable for battery-operated devices or applications where power efficiency is critical. The output from the decoder can be used to trigger other components in a system, such as microcontrollers or relays, enabling various applications such as remote control systems, automated dialing, or access control mechanisms.
In summary, this DTMF decoder circuit utilizes a dedicated CMOS IC to recognize a specified 4-digit input, selected via DIP switches, and can interface with other electronic components for further processing or action based on the detected DTMF tones. This decoder will respond to a preselected 4-digit DTMF number. IC7 is a Radio Shack IC device (part #276-1303 ). The logic is all CMOS. The digits are selected by SW1 and SW2, a pair of 8-position DIP switches.
The described circuit employs a DTMF (Dual-Tone Multi-Frequency) decoder that is designed to recognize a specific 4-digit number. The core component, IC7, is a CMOS-based integrated circuit from Radio Shack, identified by the part number 276-1303. This IC is capable of interpreting the audio tones generated by a DTMF keypad, converting them into digital signals that correspond to the pressed keys.
User interaction is facilitated through two 8-position DIP switches, labeled SW1 and SW2. These switches allow for the selection of the desired DTMF digits by configuring the binary inputs that the decoder IC reads. Each switch can be set to either a high or low state, representing binary values that correspond to the DTMF digits 0-9 and the additional symbols such as *, #, A, B, C, and D.
The overall logic of the circuit is implemented using CMOS technology, which is known for its low power consumption and high noise immunity. This makes the circuit suitable for battery-operated devices or applications where power efficiency is critical. The output from the decoder can be used to trigger other components in a system, such as microcontrollers or relays, enabling various applications such as remote control systems, automated dialing, or access control mechanisms.
In summary, this DTMF decoder circuit utilizes a dedicated CMOS IC to recognize a specified 4-digit input, selected via DIP switches, and can interface with other electronic components for further processing or action based on the detected DTMF tones. This decoder will respond to a preselected 4-digit DTMF number. IC7 is a Radio Shack IC device (part #276-1303 ). The logic is all CMOS. The digits are selected by SW1 and SW2, a pair of 8-position DIP switches.
Telephone operated remote
The circuit described is a telephone-operated DTMF remote control that can switch up to nine devices using the telephone keys 0 to 9. The digit 0 is utilized to toggle the telephone system between remote switching mode and normal conversation...
MT8870D Integrated DTMF Receiver With Enhance Sensitivity
The MT8885 is a monolithic DTMF transceiver equipped with a call progress filter. It is manufactured using CMOS technology, which ensures low power consumption and high reliability. The receiver section is designed based on the industry-standard MT8870 DTMF receiver. The...
Low-Power Metronome
This metronome operates on a current of only 0.25 mA, making it suitable for battery-powered applications. It offers a tempo range from 34 to 246 beats per minute. The circuit can utilize a CMOS timer, such as the LM555 CN...
dtmf cell phone controlled home appliances automation project
It is possible to control home and office electrical appliances using a mobile phone. This document presents a simple home automation electronic mini project circuit diagram designed for engineering students, allowing the control of electrical appliances without the use of...
Telephony DTMF Circuits
This circuit can manage nine independent telephones using a single telephone line pair located at nine different locations. It functions as a bidirectional telephone line simulator without the need for actual telephone lines, allowing for coupling, testing, and demonstration of...
DTMF INFRARED TRANSMITTER
This transmitter utilizes a 5089 DTMF generator chip along with a keypad to produce DTMF signals, which are then modulated onto an infrared (IR) light beam emitted from an IR LED. The circuit employs a 3.579-MHz TV burst crystal as...
Dtmf detection in GSM modem
A project is being developed involving GSM technology, with the objective of detecting key presses on the remote side during an active call. An attempt is being made to utilize a DTMF decoder circuit connected to the speaker output; however,...
DTMF Generation with a 3.58 MHz Crystal
Cleaned Input: DTMF (Dual Tone Multiple Frequency) is associated with digital telephony, and provides two selected output frequencies (one high band, one low band) for a duration of 100 ms. DTMF generation consists of selecting and combining two audio tone...
DTMF Tone Decoder
This project displays telephone numbers decoded from tones. A microphone picks up the tones, a preamplifier boosts the signals, an SSI-202 DTMF chip decodes the tones, a Basic Stamp acts as an interface to an LCD display and also provides...