Remote Control Circuit Through RF

Remote Control Circuit Through RF

Description

      This is a simple type remote control by using RF communication without microcontroller. In this project a remote has been designed for various home appliances like television, fan, lights, etc. It gives lot of comfort to the user since we can operate it by staying at one place. We can control any of the appliances by using this remote within the range of 400 foots(121 meters). In this project consist of two sections, transmitter (remote) and receiver section. Whenever we are pressing any key in the remote it generates the corresponding RF signals, and these signals are received by the receiver unit. ASK transmitter and receiver is used as transmitter and receiver. HT12E, HT12D encoders and decoders are used in this electronic circuit.

 Remote Section

    In remote section consist of an encoder (HT 12E) and a ASK transmitter. The encoder generates 8 bit address and 4bit data. We can set the address by using the DIP switch connected in A0 to A7 (pin 1 to 8 ) encoder. If we set an address in the remote section, the same address will be required in the receiver section. So always set same address in transmitter and receiver. Whenever we press any key in the remote the encoder generates corresponding 4bit data and send this data with 8bit address by using ASK transmitter. The transmitting frequency is 433MHz. The transmitter output is up to 8mW at 433.92MHz with a range of approximately 400 foot (open area) outdoors.  Indoors, the range is approximately 200 foot.

 

Receiver Section

     At the receiver section ASK receiver is present. The receiver also operates at 433.92MHz, and has a sensitivity of 3uV.  The ASK receiver operates from 4.5 to 5.5 volts-DC, and has both linear and digital outputs. It receives the datas from the transmitter. Then the decoder (HT 12D) decodes the date and it will enable the corresponding output pin (pin 10,11,12,13). Each output pins are connected to separate flip flops. The output of encoder will change the state of the flip flop. So its output goes to set (high) from reset (low) state. This change makes a high signal in the output of the flip flop. This output signal is not capable to drive a relay directly. So we are using current driver, SL100 transistor act as the current driver. The appliance is connected to 230V AC through the relay and the appliance will start. The relay will be re-energized when the same switch is pressed in the remote. This is because we are pressing the same switch in the remote control. The output of the decoder again goes to high so this signal will again change the state of the flip flop. So, the relay gets re-energized and the appliance goes to OFF state.

Components Used

        

 

Home Security System Using LDR

Home Security System using LDR 

Description:-  

         in this figure you have seen the home security system using LDR. After making this circuit flowed the torch ray on the LDR if you have break the ray of light the base of the transister Q1 is positive so this time the transister is off. After that the pin no. two of the integrated circuit U1 is negative so the integrated circuit U1 will be triggred and the output will be ON. when who don't break the torch ray. this time the base of transister is negative so the pin no. 2 of the integrated circuit U1 is positive. So this time the inegrated circuit U1 will be OFF, Assemble this circuit on Good Quality PCB or Dott Matrix Board

Part List:-

1.5 Volt to 9 Volt inverter

How to boost 1.5 volt to 9 Volt (low current projects) 

This booster is very simple to made at home required some electronics component.

It is use for low current required projects. The output current is less then 10 mA.

Input voltage is 1.5 to 4.5 Volts. 

In this circuit the L1 coil is 60 turns on a 10 mm ferrite slug 15 mm long, and wire is 0.25 mm diameter enameled wire.

Circuit Diagram  is below :- 

 

1.5 Volt to 3 Volt Booster

A very simple circuit to boost 1.5 Volt(Cell voltage) to 3 Volt

 In this circuit using a multivibrator 

  

 

Part list:- 

R1,R3:-1K 

R2:- 2.2K

C1:- 470 pF

C2:- 100uF/ 3.3 Volt

C3:- 1000uF

L1:- 470uH

VD1:- 15MQ040

VT1,VT2:- BC547

           you can use this booster can be used power supply for LED or Low power devices.