We’ve all been there. That cold sweat that sets in after you’ve checked your pockets, your bag, the car and down the back of the sofa and you still haven’t found your beloved smartphone.

However, savvy Android users need fret no longer, as Android Device Manager is here to reunite you with your walkabout gadgetry.

If your device is associated with your Google account, you can use the service to find the approximate location of your device, reset the password or even perform a complete factory reset. Best of all, it’s a complete doddle to set up.

Android Device Manager Locate a lost device

1: Turn it on
Find the Google Settings app on your smartphone (a green box with a G and some cogs in it) then hit the Android Device Manager option. Check both tick boxes then on your computer navigate to and sign into your Google account.

2: Get online
Tap Accept if it asks you to allow location data. Providing your device is on and within the range of mobile data or Wi-fi, you’ll then see the location of your device on Google Maps plus other useful info such as an approximate address and last-location date and time.

3: Ring or lock
You now have a few options. You can use the button on the left to ring your phone at full volume for five minutes, a really handy feature if you’re near it but can’t see it! You can also use the middle button to remotely lock your phone with a new password.

4: Remote factory reset
The Erase button will perform a remote factory reset on your device. All of your apps, photos, music and settings will be deleted. It’s irreversible, but if your phone has been lost or stolen and you have no hope of recovering it, this is a useful means of protecting your personal details.


Here is a simple Power Supply for your electronics project.

Circuit description: aC mains 230V aC is down converted to 15V aC by the step-down transformer X1, the secondary winding of which can support a current of 2 amperes. a bridge rectifier converts
the aC to pulsating DC with a peak voltage level of 21V (15x1.4142). lED1 lights up to indicate
availability of output from the rectifier. The 2.2 kilo-ohm resistor R1 limits the current through
lED1 to a value below 10ma (milli-ampere). The output from bridge rectifier is smoothed by 470μF capacitor C1. C2 is used for bypassing high frequency ripple.

Schematic diagram of power supply.

iC1 - lM317T - 1.5a adjustable
D1-D9 - 1N4007 - rectifier diode
lED1 - 5mm - red lED
R1 - 2.2 kilo-ohm - 0.25W, 1% MFR
R2 - 220-ohm - 0.25W, 1% MFR
R3 - 100-ohm - 0.25W, 1% MFR
R4 - 1.8 kilo-ohm - 0.25W, 1% MFR
R5 - 4.7 kilo-ohm - 0.25W, 1% MFR
R6 - 1.5 kilo-ohm - 0.25W, 1% MFR
R7 - 1 kilo-ohm - 0.25W, 1% MFR
R8 - 390-ohm - 0.25W, 1% MFR
C1 - 470μF, 63V electrolytic
C2 - 0.1μF ceramic disk
C3 - 10μF, 25V electrolytic
X1 - 230V aC primary to 15V aC, 2a
secondary transformer
S1 - Switch toggle, SpST
F1 - Fuse cartridge, 2a (with holder)
S2 - Switch rotary, single-pole 5-way
(in lieu Dip switch 6-way)
- heatsink
- Box for mounting hardware and
- lED holder
- Tag blocks for input
- Screwable binding posts for output
- Screws with nuts and washers
- insulated spacers for mounting pCB


We are rounding down the best student books and reference about electronics.

1. Practical Electronics for Inventors
by Paul Scherz  (Author), Simon Monk  (Author)

"If there is a successor to Make: Electronics, then I believe it would have to be Practical Electronics for Inventors....perfect for an electrical engineering student or maybe a high school student with a strong aptitude for electronics....I’ve been anxiously awaiting this update, and it was well worth the wait."--GeekDad (

Spark your creativity and gain the electronics skills required to transform your innovative ideas into functioning gadgets. This hands-on, updated guide outlines electrical principles and provides thorough, easy-to-follow instructions, schematics, and illustrations. Find out how to select components, safely assemble circuits, perform error tests, and build plug-and-play prototypes. Practical Electronics for Inventors, Third Edition, features all-new chapters on sensors, microcontrollers, modular electronics, and the latest software tools.

2. Make: Electronics (Learning by Discovery) 
by Charles Platt  (Author)

"This is teaching at its best!"

--Hans Camenzind, inventor of the 555 timer (the world's most successful integrated circuit), and author of Much Ado About Almost Nothing: Man's Encounter with the Electron (

"A fabulous book: well written, well paced, fun, and informative. I also love the sense of humor. It's very good at disarming the fear. And it's gorgeous. I'll be recommending this book highly."

--Tom Igoe, author of Physical Computing and Making Things Talk

Want to learn the fundamentals of electronics in a fun, hands-on way? With Make: Electronics, you'll start working on real projects as soon as you crack open the book. Explore all of the key components and essential principles through a series of fascinating experiments. You'll build the circuits first, then learn the theory behind them!

Build working devices, from simple to complexYou'll start with the basics and then move on to more complicated projects. Go from switching circuits to integrated circuits, and from simple alarms to programmable microcontrollers. Step-by-step instructions and more than 500 full-color photographs and illustrations will help you use -- and understand -- electronics concepts and techniques.

3. Getting Started in Electronics 
by Forrest M. Mims III  (Author)

This is a complete electronics course in 128 pages! Author Forrest Mims teaches you the basics, takes you on a tour of analog and digital components, explains how they work, and shows you how they are combines for various applications. Includes circuit assembly tips and 100 electronic circuits and projects you can build and test.

4. Complete Electronics Self-Teaching Guide with Projects
by Earl Boysen  (Author), Harry Kybett (Author)

An all-in-one resource on everything electronics-related!
For almost 30 years, this book has been a classic text for electronics enthusiasts. Now completely updated for today's technology, this latest version combines concepts, self-tests, and hands-on projects to offer you a completely repackaged and revised resource. This unique self-teaching guide features easy-to-understand explanations that are presented in a user-friendly format to help you learn the essentials you need to work with electronic circuits.

All you need is a general understanding of electronics concepts such as Ohm's law and current flow, and an acquaintance with first-year algebra. The question-and-answer format, illustrative experiments, and self-tests at the end of each chapter make it easy for you to learn at your own speed.

5. How to Diagnose and Fix Everything Electronic
by Michael Geier  (Author)

In this hands-on guide, a lifelong electronics repair guru shares his tested techniques and invaluable insights. How to Diagnose and Fix Everything Electronic shows you how to repair and extend the life of all kinds of solid-state devices, from modern digital gadgetry to cherished analog products of yesteryear.

You'll start by selecting the tools and test equipment you'll need and setting up your workbench. Then, you'll get familiar with components and how they form circuits, stages, and sections of a device. Next, you'll learn how to take a product apart, figure out what's wrong with it, replace components, and reassemble it. Real-world case studies help clarify the topics covered. Tips and tricks for specific devices, such as optical disc players, computers, and video recorders, are also included in this practical resource.