REMOTE SWITCH USING FM FREQUENCY

6TP09

2B-REMOTE SWITCH using FM Frequency

PROJECT SPECIALITIES

The main speciality of this project is that it  controls the object without any wiring and medium from remote.  Sitting at a distance of 100 meters you can control any equipment just as a hand unit transmitter remotely controls the things.  This works as a ON/OFF switch and it is a  type of a cordless remote switch.  It is like a remote control TV switch.  Now-a-days its utility has increased because you can operate it any where.

TECHNICAL DESCRIPTION AND WORKING

This project has been developed and tested O.K. in our TV Engineers Technical Lab.  The components and PCB used in the projects published in our books are available for sale at resonable price.

Due to cordless operation of this project it has two parts.

  1. Hand Unit Remote [Transmitter]
  2. Receiver Circuit

The technical details of both units are given below.

  1. Hand Unit and Remote [Transmitter]

There is an Oscillator circuit in this unit of the project.  This oscillator works on the FM meter band.  The receiver used with this unit also receives signal in FM range given by the transmitter.  To increase the distance covered this circuit is consist of three transistors.  The oscillator unit is consist of transister BF494.  Its supply voltage is 9V DC.  The battery is used for this purpose because it produces no noise in the signal.  When switch is pressed the glow of the LED indicates that hand unit or transmitter unit is working.

  1. Receiver & Switch Circuit

The second part of this project is called receiver section which works as a switch. The signal given by the transmitter which are in the FM range are received by it. Transister Q1 & Q2 are employed in the receiver section. Transister Q3 changes these signals in to audio signal. Transister Q4, Q5, Q6 and Q7 amplify the signal and these are sent to the relay through the collector of Q8. This relay acts as a switch and can ON/OFF any equipment.

PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-

* First of check all components whether these are as per the circuit diagram or not.

* Take care of the polarity of the diode while contacting it on the PCB.

* Take care for the cleanness while soldering the PCB.  There should not be any shorting on the print.

PART LIST:-

FM SWITCH [ RECEIVER SECTION]

PCB [CODE 6TP09]=1

Semi-Conductor

BC548=5, BF494=1, BC158=2

IN4007=4, IN4446=3

Resistance

22K=2, 100K=1, 33K=1, 1M=1, 330K=1, 10K=5, 22E=1, 1K=2, 4K7=1, 47K=6, 15K=2, 100E=1

Capacitor

0.001=2, 0.002=3, 47pf=1, 0.04pf=1, 0.01pf=2, 0.1pf=2

470mfd/16V=1, 220mfd/16V=1, 2.2mfd/16V=3

TRIMMER =1

COIL [RF]=2

RELAY 12V=1

[TRANSMITTER SECTION]

Resistance

47K=1, 2K7=2, 1K=1,330K=1

Capacitor

0.001pf=3, 0.002pf=1, 4.7pf=1

RF COIL =1, Trimmer =1

PUSH TO ON SWITCH =1, AERIAL=1

Misc.

Cabinet =1

Ever-Ready Cell 9V =1