This circuit will allow you to control any electrical gadget from any part of the world through your cellphone remotely, that too without spending a penny for the individual commands.
Whether it’s you vehicle, your basement door, your mansion gate or simply the air conditioner of your house, everything can now be switched by just a flick of your cell phone button.
And yes, it’s completely fool proof, meaning no false triggering is possible through any other cell phone signals, it works only through the owners cell phone commands.
The explained circuit must be employed strictly for operating only the following specified equipment:
All domestic electrical appliances like, lights, fans, motors, TV sets, refrigerators, Air conditioners, washing machine, porch lights, garage door, house gate, basement gate or entrance, car ignition, car doors, water heater etc.
The concept has been already discussed in one of my previous articles – How to make a GSM car security system, and the going about is unbelievably simple.
However, the above article deals with a system that involves DC control features and therefore is not suited for controlling AC appliances.
The unit discussed here is a universal device and can be used for operating all types of electrical gadgets from any part of the globe, just by making a single blank call to the systems number.
The system will faithfully respond to every call made from your cell phone and will alternately switch the connected load ON and OFF as per your instructions.
The concept is impeccable, as it has been tested by me thoroughly since last three years with flying results.
Basically the unit employs a very fundamental principle of converting the ringtone of a cell phone into a command output for operating a relay.
This cell phone acts as a modem and is permanently attached with the internal control circuit of the unit. The modem cell phone is initially made ready by putting a SIM card inside it and by configuring the essential assigned numbers into its phone directory.
These assigned numbers are the only numbers to which this modem responds. Therefore you would want to assign only those numbers through which you may like to make a call to the “system”.
For safety reasons more than one number is assigned to the modem so that in case one of your cell phones is out of order or has low battery, you always have the option of using the other cell phone for triggering the system.
The biggest advantage of the GSM cellphone remote control circuit is that, any cheap NOKIA cell phone can be used here as the modem and therefore there’s no fear of the modem becoming obsolete.A simple yet effective cell phone remote control switch details has been discussed here with complete schematics and step by step tutorial.
If you have sufficient prior knowledge of electronics, you should be making this complete unit within a days time. Let's begin the discussion. Basic Concept The idea here is to use an ordinary NOKIA 1280 cell phone as the modem attached permanently with a switching circuit. This entire unit now becomes the receiver unit.
Let's learn the building process. You will have first get or procure the following materials or parts for making this unit. I would suggest not to make the Printed board initially, it would better to first test the working over a general board and if thing goes then you would want to transfer it over a well designed P-C-B.
Bill of Materials
All resistors are 1/4w 5% CFR unless otherwise stated.
L1 is a buzzer coil, as used in piezo electric buzzers, or may be hand made by winding 1000 turns of 36SWG super enameled wire over a small ferrite core, size and shape does not matter. Image of L1, inside a buzzer
The period for which RL1 remains switched ON will have no consequence on the flip flop operation, the flip flop will switch ON and OFF in response to every subsequent missed call made from the owners cell phone.
How to Power the Unit