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Duel Tone Multi
Frequency Circuits
Last Updated on:
Monday, March 26, 2012 08:11 PM |
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Links to electronic circuits,
electronic schematics, designs for engineers, hobbyists, students & inventors:
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AN-521: Dual Tone Multiple Frequency DTMF - National Semiconductor
Application Note (app note added 2/06) |
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AN-666: DTMF Generation with 3.58 MHz Crystal - National Semiconductor
Application Note (app note added 2/06) |
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Device Control using DTMF - Controlling devices using switches are
common. From a few decades controlling devices using remote control switches like
infrared remote control switch, wireless remote control switches, light activated
switches are becoming popular. But these technologies have their own limitations.
Laser beams are harmful to mankind. …..... |
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DTMF Coder Makes Low Cost Sine Wave Generator - 10/13/94 EDN-Design
Ideas.....A telephone DTMF IC produces, by design, two tones if you connect a
single intersection of the IC's 4[x]4 keypad matrix (Fig 1]..... EDN is migrating
links. This link is not verified. Search the "title" + "EDN" for new link.
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DTMF Decoder - Uses MT8870 DTMF decoder and PIC microcontroller
to decode telephone tones. …..... |
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DTMF Decoder for PC - Our DTMF decoder can be powered from a 9V
battery or from your parallel printer port. It can detect and display all
16 DTMF digits on your computer screen in real-time. The Window's program
can be placed….(design added 11/08) |
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DTMF Decoder with LCD Display - The DTMF decoder 2 is a useful
tool used for decoding DTMF (Dual Tone Multi frequency) generated by
telephones..... |
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DTMF Generation with 3.58 MHz Crystal - National Semiconductor
Application Note (app note added 2/06) |
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DTMF Generator/Decoder - (Circuit design added 04/05/06)
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DTMF Products for you - DTMF decoder can be powered from a 9V
battery or from your parallel printer, schematic and windows demo program,
design by Schmidt Technologies (added 5/02) |
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DTMF Proximity Detector - ..... |
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DTMF Radio Remote Control - Here is a circuit of a remote
control unit which makes use of the radio frequency signals to control
various electrical appliances. This remote control unit has 4
channels which can be easily extended to 12. .... |
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DTMF RECEIVER - Today, most telephone equipment use a DTMF receiver IC.
One common DTMF receiver IC is the Motorola MT8870 that is widely used in
electronic communications circuits. The MT8870 is an 18-pin IC. It is used in
telephones and a variety of other applications. When a proper output is not
obtained in projects using this IC, engineers or technicians need to test this IC
separately. A quick testing of this IC could save a lot of time in research labs
and manufacturing industries of communication instruments.….(design added 11/08)
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DTMF Tone Decoder - hears touch tones and displays them as telephone
numbers...... |
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Dual Tone Multiple Frequency DTMF - National Semiconductor Application
Notes first published04-Nov-1995 (app note added 04/03/02) |
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Full-duplex doorphone with 3 Wires connection - a two-way (full-duplex)
construction planned for use as doorphone…. [Peter Jakab, Electrical Engineer,
Engineer of Informatics] |
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Radio Remote Control using DTMF - Here is a circuit of a remote control
unit which makes use of the radio frequency signals to control various electrical
appliances. This remote control unit has 4 channels which can be easily
extended to 12. This circuit differs from similar circuits in view of its
simplicity and a totally different concept of generating the control signals.....
[Radioland.net] |
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Remote control using telephone - Here is a tele-remote circuit which
enables switching "on" and "off" of appliances through Telephone lines. The
circuit described here can be used to switch up to nine appliances (corresponding
to the digits1 through 9 of DTMF the Telephone key-pad). The Telephone can be used
to switch.....(added 5/02) |
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Simulate signals for telecomm tests - 9/11/98 EDN-Design Ideas.....The
circuit in Figure 1 is a miniature gadget that is helpful in
telecommunication applications. The function of the device is to simulate data
flow with predefined patterns and use these patterns to check a cable's or a
receiver's functionality. The circuit generates a signal in accordance.....File
has several circuits, please scroll to find this one..... [Design Idea by Samuel
Kerem, Patton Electronics, Gaithersburg, MD] |
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