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Basic Flashlamp Illumination Circuitry for Cellular Telephones/Cameras - DN345
Design Notes (Linear Technology) (app note added 1/06) |
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BayComm packet modem - (circuit / schematic added 6/05) |
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Build A HamComm Data Slicer - Until recently many of the ham radio operating modes
required specialist equipment that most often had to by build and was exclusive to the
task. Enter the Personal Computer. The PC made life a little easier for the ham as it
was now able to take over some of the jobs that bespoke hardware did. But it still
wasn't quite there yet. The task of the PC was mainly to be a 'front end' ...
(circuit / schematic added 6/07) |
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Build your own 89C51 PABX - This 89C51 PABX project is basically an eight line
intercom from which you can call one to eight numbers. The 89C51 PABX system also
supports dialling and receiving telephone calls….(circuit / schematic added 09/08) |
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Caller ID Circuits - information and circuits for different systems used USA and
Finland (added 5/02) |
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Caller ID Decoder - (circuit / design added 8/03) |
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Caller ID Display Service - Caller ID decoder based on 68HC11, text in French /
(added 8/03) |
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Cell-Phone-Controlled Audio/Video Mute Switch - (electronic Circuit / Schematic
added 10/04) |
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Cellular Phone calling Detector - Flashes a LED when detecting an incoming call.
Powered by one 1.5V cell (added 4/05) |
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Chip recorder customizes phone ringer - 07/25/02 EDN-Design Ideas:
Companies usually purchase one type of telephone for all employees, which is
understandable, especially if they obtain a discount for buying in quantity. One
ringer sound for everyone can pose a problem, though, if the sound of a ringing phone
makes a dozen people pause and look at their telephones. Equally annoying is the
absence of a visual message.....(design idea added 01/05) |
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Circuit Provides Message on Disabled Phone Line - 01/20/00 EDN-Design Ideas:
/ This circuits plays a prerecorded message into any phone on the line when its
receiver goes off-hook.....(design idea added 5/02) |
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Circuit Translates a Law to µ Law - 05/07/98 EDN-Design Ideas: (design idea
added 11/05) |
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Circuit Vocalizes Telephone Number - 02/03/94 EDN-Design Ideas: The circuit
in Fig 1 is a simple method of vocalizing the digit number of a telephone keypad,
which, for someone visually impaired, provides helpful voice confirmation. A 75T202
dual-tone multifrequency (DTMF)receiver decodes the DTMF signal when you depress the
phone's keypad. The TC8801N voice synthesizer.....(design idea added 3/03) |
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Circuitry for Cellular Telephone/Camera Flash Illumination - AN95 Linear
Technology This publication concerns implementation of high quality "Flash"
illumination in cellular telephones/cameras. Performance vs LED based illumination is
discussed and flashlamp operation reviewed. Considerations for support circuitry are
given, and a practical circuit, accompanied by performance data,....(appnote added
1/06) |
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Clip extracts signal from phone line - 07/24/03 EDN-Design Ideas: This
Design Idea presents a differential safety device to prevent risks arising from
current leakages in household applications. The proposed circuit uses a new method for
differential current sensing (Figure 1)….....(design idea added 1/05) |
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Connecting a Picmicro® Microcontroller to a Standard Analog Telephone Line -
Microchip Application Note Published 21-Aug-02 (app note added 6/06) |
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Conversation Recorder - (electronic circuit added 10/05) |
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Cordless Phone Backup - (electronic Circuit / Schematic added 10/04) |
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Creating your Own Telephone Ne2 Rk - you can easily create your own intercom
system using two telephones, a 9-volt battery (or some other simple power supply) and
a300-ohm resistor (added 5/02) |
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Cut Phone Line Detector (Aaron Cake) - Can be used to alarm security system (added
5/02) |
