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Wireless Telephone Circuits
 

Last Updated: December 31, 2017 06:45 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. . . Circuit by David Johnson P.E.-July, 2006

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 difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme . . . Hobby Circuit designed by David A. Johnson P.E.-August, 2009

Cell Phone Solar Powered 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 . . . Hobby Circuit designed by David A. Johnson P.E.-January, 2011

Detect RF Signal at 2.45GHz -  Many cordless telephones, computer networks and cell phones use a RF transmitter lefted on the 2.45GHz band.  Using a microwave diode detector and 100uA meter, this passive circuit will display the strength this signal.  The drawing shows how a bent piece of wire can be used as the antenna. . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

DIY 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 difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme . . . Hobby Circuit designed by David Johnson P.E.-August, 2009

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 difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme. . . Circuit by Dave Johnson P.E.-August, 2009

RF 2.45Ghz 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 . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747




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

1-NiCd Cells Drives Op Amp -  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 NIC d/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 __ Circuit Design by Alexander Belousov, Rego Park, NY

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. . . Circuit by David Johnson P.E.-July, 2006

6 Volt Gel Cell Charger -  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.   __ Designed by Tony van Roon  VA3AVR

A Practical Guide for Successfully Implementing Flashlamps -  Linear Technology AN95 __ Designed by Jim Williams - Mar 1st, 2004

Basic FlashLamp Illuminationry for Cellular Telephones/Cameras -  DN345 Design Notes__ Linear Technology/Analog Devices

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 difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme . . . Hobby Circuit designed by David A. Johnson P.E.-August, 2009

Cell Phone Detector aka Mobile Bug -  This handy mobile bug or cell phone detector, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cellphone from a distance of one and-a-half metres.  So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc.  it is also useful for detecting the __ Designed by Popescu Marian

Cell Phone Solar Powered 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 . . . Hobby Circuit designed by David A. Johnson P.E.-January, 2011

Cellphone Operated Land Rover. Part 1. Schematic -  Conventionally, wireless-controlled robots use RF circuits, which have the drawbacks of limited working range, limited frequency range and limited control.  Use of a mobile phone for robotic control can overcome these limitations.  it __ Designed by lik Zohaib

Cellphone Operated Land Rover. Part 2. Software -  Part 1.  Schematic Software description: The software is written in ‘C’ language and compiled using CodeVision AVR ‘C’ compiler.  The source program is converted into hex code by the compiler.  Burn this hex code __ Designed by lik Zohaib

Cellphone-Based Device Control with Voice Acknowledgement -  Here is a circuit that lets you operate your home appliances like lights and water pump from your office or any other remote place.  So if you forgot to switch off...__ Electronics Projects for You

Cellphone-Based Remote Controller for Water Pump -  inconvenience in switching on a water pump installed in a remote farm is a common problem faced by farmers.  Many circuits have been developed to solve this problem.  Most of them...__ Electronics Projects for You

Cell-Phone-Controlled Audio/ Video Mute Switch -  This cell-phone-controlled audio/video mute switch is highly useful in automobiles.  The circuit automatically disconnects power supply to the audio/video system whenever the mobile handset is lifted off the holder for making...__ Electronics Projects for You

Cellular Phone calling Detector -  Flashes a LED when detecting an incoming call; Powered by one 1.5V cell __ Contact Flavio Dellepiane, fladello @ tin.it

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" __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

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, __ Linear Technology/Analog Devices

Converting Cellular Phones to 900 MHz -  Use old Motorola cellular phones as if rigs in a 900 MHz transmitter.  __ Amateur Radio circuits from Green Bay Professional Packet Radio

Cordless Phone Backup -  Normally the base of a cordless phone has an adaptor and the handset has Ni-Cd cells for its operation.  The base unit becomes inoperative in case of power failure.  Under such...__ Electronics Projects for You

Detect RF Signal at 2.45GHz -  Many cordless telephones, computer networks and cell phones use a RF transmitter lefted on the 2.45GHz band.  Using a microwave diode detector and 100uA meter, this passive circuit will display the strength this signal.  The drawing shows how a bent piece of wire can be used as the antenna. . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

DIY 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 difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme . . . Hobby Circuit designed by David Johnson P.E.-August, 2009

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 difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme. . . Circuit by Dave Johnson P.E.-August, 2009

DualVoltage Supply Powers SIM Card -  App 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__ 

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.   __ Designed by Tony van Roon  VA3AVR

GellCell Battery Charger -  Recently, a fellow amateur was looking for a gel cell charger which would first charge at a fixed rate and then later switch to a trickle charge when the cell was fully charged.  After reviewing several catalogs and web sites, the MAX712 IC was discovered.  This IC meets all the requirements for almost any type of battery charging system.  The circuit in Figure 1 was designed specifically for 12 volt gel cells __ Designed by Radio Amateur Society of Norwich

Introduction to Smart Wi-Fi -  We need faster tools and media to prove our ideas, and this is where ready-to use modules like Smart Wi-Fi enter.  Fig.1 shows the top side of Smart Wi-Fi module. The...__ Electronics Projects for You

Mobile Cellphone Charger -  Charging of the cellphone battery is a big problem while travelling as power supply source is not generally accessible.  if you keep your cellphone switched on continuously, its battery will go...__ Electronics Projects for You

Mobile Charging With Heat Using A Teg Module -  This circuit can come in handy when you are camping in a remote area where there is no electricity available to charge your mobile phone’s or tablet’s battery. if you can...__ Electronics Projects for You

Mobile Phone Battery Charger -  Mobile phone chargers available in the market are quite expensive.  The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, such...__ Electronics Projects for You

Mobile Phone Multipower Unit -  Most of the mobile phone complaints are related to the power supply.  This is mainly because of improper charging and use of non-recommended chargers and low-quality batteries.  Depending upon the make...__ Electronics Projects for You

Mobile Phone Sniffer-GSM Telephone Detector -  This handy, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cellphone from a distance of one and-a-half metres.  So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc.  it is also useful for detecting the use of mobile phone for spying __ Designed by Popescu Marian

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 __ Designed by Published in Elecktor July/Aug, 2010

Mobile Shield -  Protect your mobile phone from unauthorised use or theft using this simple circuit.  it can generate a loud chirping sound when somebody attempts to take away the mobile handset.  The added...__ Electronics Projects for You

Mobile Sniffer -  This circuit can detect the use of a GSM mobile in mobile-phone-restricted areas such as examination halls and other ‘do not disturb’ areas.  it can detect the activity of the phone...__ Electronics Projects for You

NiCd Cells Drives Op Amp -  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 NIC d/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 __ Circuit Design by Alexander Belousov, Rego Park, NY

PCS: 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 __ Circuit Design by Stephen Kempainen, Technical EDFtor

Power Bank for Smartphones -  This power bank can be used for charging smartphones.  The circuit uses two integrated modules and a lithium-ion battery.  The first module is a lithium-ion battery charger and the second is...__ Electronics Projects for You

Practical Guide for Successfully Implementing Flashlamps -  Linear Technology AN95 __ Designed by Jim Williams - Mar 1st, 2004

RF 2.45Ghz 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 . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Simple Circuitry for Cellular Telephone/Camera Flash Illumination -  Linear Technology AN95 __ Designed by Jim Williams - Mar 1st, 2004

Simplery 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, __ Linear Technology/Analog Devices

Single NiCd Cells Drives Op Amp -  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 NIC d/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 __ Circuit Design by Alexander Belousov, Rego Park, NY

Smart Cellphone Holder -  This smart cellphone holder makes sure that you don’t forget to carry your mobile phone.  Fitted in the car, it keeps searching for the mobile phone within the holder using infrared...__ Electronics Projects for You

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. . . Circuit by David A. Johnson P.E.-January, 2011

The Phone Catcher -  I have had and used other devices that detect radio signals for years, so I have seen my telephone emitting signals at times other than those at which I was using it to talk with somebody.  This Cell Phone Catcher lights an LED indicator light and whenever the phone transmits, so even the briefest of transmission can be seen.  The LED stays on until press the RESET button.   __ Designed by Dick Cappels

Tiny Efficient High Power LED Camera Flash Solutions for Cell Phone Applications -  Design Notes 231__ Linear Technology/Analog Devices

UPS for Cordless Telephones -  Cordless telephones are very popular nowadays.  But they have a major drawback, i.e.  they cannot be operated during power failure.  Therefore usually another ordinary telephone is connected in parallel to the...__ Electronics Projects for You


Wireless Telephone Circuits


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