Wireless Telephone Electronic Circuits

Wireless Telephone Circuits
Last Updated on: Saturday, April 14, 2012 06:48 AM

Circuits Designed by Dave Johnson, P.E. :

2.45GHz RF Signal Detector
This passive RF indicator is made from a few simple parts. A 100uA moving coil meter is used to display the relative intensity of the RF signal. This circuit can be used with some cell phones and many cordless telephones. (added 7/06)

Do It Yourself Portable Cell Phone Charger
It seems that as cell phones become more sophisticated, their operating times become shorter and shorter. If you are on the go all the time and have difficultly finding AC or DC outlets to charge your phone, you might consider this simple scheme....

Solar Powered Cell Phone Charger
The simple circuit below regulates the voltage from a 6v solar panel to a fixed +5v. That voltage can be fed to any cell phone or USB connected portable device, to charge its battery. The circuit uses a Reg113-5 voltage regulator from Texas Instruments. The tiny device can handle up to 400ma of charging current. I would suggest using a solar panel rated for less than 2 watts and one which contains 12 solar cells. One such panel is shown below.

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

Do It Yourself Portable Cell Phone Charger - It seems that as cell phones become more sophisticated, their operating times become shorter and shorter. If you are on the go all the time and have difficultly finding AC or DC outlets to charge your phone, you might consider this simple scheme.... [Designed by David A. Johnson]

2.45GHz RF Signal Detector - This passive RF indicator is made from a few simple parts. A 100uA moving coil meter is used to display the relative intensity of the RF signal. This circuit can be used with some cell phones and many cordless telephones. (added 7/06) …. [Hobby Corner Circuit by Dave Johnson]

AN-42036/ PCB Grounding System & FAN2001/FAN2011 High Performance DC-DC Converters - Fairchild Application Notes / (app note added 6/06)

Analog Switch Applications in a MultiMode Cell Phone - Pericom Semiconductor Application Brief # 028 (app note added 02/06)

Basic FlashLamp Illumination Circuitry for Cellular Telephones/Cameras - DN345 Design Notes (Linear Technology) (app note added 6/06)

Cell-Phone-Controlled Audio/Video Mute Switch - ....

Cellular Phone calling Detector - Flashes a LED when detecting an incoming call. Powered by one 1.5V cell (added 4/05)

Cellular Phone Helper - When your cellular phone receives a call, it begins transmitting even before you answer. The circuit shown in fig.1 detects this signal and can operate a variety of devices referred to as "load"….(circuit / design added 8/03)

Circuitry for Cellular Telephone/Camera Flash Illumination - AN95 Linear TechnologyThis 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)

Cordless phone backup - (electronic diagram added 10/06)

DualVoltage Supply Powers SIM Card - Maxim APPLICATION NOTE 1763: Global-system-for-mobile-communication phones have a subscriber-identification module (SIM) that allows local wireless providers to recognize the user and his or her billing information. Although most....(design idea added 06/03)

Gel Cell Charger, II - This circuit needs a regulated 10V-DC front end capable of supplying 2 Amps. Starts the charge cycle at 240mA and at full charge switches automatically to a float condition (trickle charge) of 12mA…. [Tony van Roon's circuit]

GellCell Battery Charger - circuit to charge a Gell Cell or other lead-acid type battery, includes sense circuit (added 2/06)

Mobile Cellphone Charger - ....

Mobile Phone TX Demo - This is a very simple and cheap device that demonstrates mobile phones (US: 'cell phones') generate RF energy (radio waves) strong enough to light an LED.….must register on this site.... [Published in Elecktor July/August 2010]

Mobile Solutions MP3 Cell phone PDA PMP - Pericom Semiconductor Application Brief # 046 (app note added 02/06)

PCB Grounding System & FAN2001/FAN2011 High Performance DC-DC Converters/ AN-42036 - Fairchild Application Notes / (app note added 6/06)

PC's: not just another cell phone - 11/21/96 EDN-Design Feature Low-cost, high-functionality digital chip sets are becoming available for wireless base-station and terminal, or handset, applications, making personal communications service (PCS] affordable enough for mass-market deployment. As new capabilities emerge, PCS may even begin to rival wireline telephones as the predominant way.... [Design Feature by Stephen Kempainen, Technical EDFtor]

Simple Circuitry for Cellular Telephone/Camera Flash Illumination - AN95 Linear TechnologyThis 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)

Single NiCd Cell Drives OpAmp - 12/05/96 EDN-Design Ideas.Low-supply-voltage op amps, such as the LMC6582 and LMC6681 families, feature rail-to-rail I/O with a gain-bandwidth product greater than 1 MHz operating from just 1.8V. Although impressive, this voltage is not low enough to power these amps using a single alkaline or NiCd/NiMH cell, which have typical voltages of 1.25 to 1.5V. It is rather tempting to bridge this gap by designing a dc/dc converter.... [Design Idea by Alexander Belousov, Rego Park, NY]

Tiny Efficient High Power LED Camera Flash Solutions for Cell Phone Applications - Linear Technology Design Note 1009....[App Note]

Wireless Telephone Circuits