Harsha COMMUNICATIONS

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Automatic Street Light Controller Circuit Using Relays and LDR

Summary: Did you ever think that how the street lights automatically turn ON in the night and turn OFF automatically at morning? Is there any person who comes to ON/OFF these lights? The following circuit that described below which perform this job automatically. This circuit employed the output from an uncomplicated light/dark activated circuit and oblige a relay in its output which can be further attached to switch ON/OFF a street light and electrical application in a household also. Many of the people have a phobia of darkness, so to assist them in such situation, we have explained a simple circuit . It will automatically turn on street light in the way of LED’s or bulb coupled with relay, it is well enough to see the object nearby. This circuit is very much easy to work and also the battery power consumed by the circuit is very low because of the very few components used in the circuit. Also Read the Interesting Post: Automatic Plant Watering Syste

FM Bugger Circuit

We know that bugger is a device which gives the information of one person to other person in the remote location. Normally bugger is used for finding out the status of the person like where he is going, what he is talking etc. This is illegal but most of spy agencies use this bugger. Here is small circuit with which you can listen to another people conversation from long distance using the normal FM radio set. This FM bugger circuit is kept in room where you want listen the conversation. You can listen to this conversation using the normal FM radio set. FM Bugger Block Diagram: From the block diagram we can easily understand that the message signal or conversation signal is modulated with the carrier frequency which is generated by the tank circuit . The message signal and carrier signal is modulated by the transistor and transmit the modulated signal in the air through the antenna. The modulated signal is received by the receiver antenna and gives to the FM rad

Electronic Letter Box Project Circuit

The circuit which is explained below is been employed as an Electronic Letter Box. When letter drop by someone into the letter box then the LED attached at the output stops blinking which indicates that there is a letter in your letter box. To identify the presence of a letter in the box we have connected a LDR as well as source of light. LDR is a special kind of resistor whose action based on the intensity of light declining on it. In the time of total darkness LDR resistance is approx 1 mega ohm while at the time of bright light its resistance is 2-5 ohm. In this circuit the light source is adjusted with the LDR in such a way that the light will directly drop on the LDR so that when any letter comes inside the letter box it will chunk the light beam and LDR will be beneath darkness. Electronic Letter Box Circuit Diagram: Circuit Diagram of Electronic Letter Box Circuit Components : IC LM741 – 1 CD4001 – 1 Resistors R1(2.2M) – 1 R2(560K) – 1 R3,R4,R5(1K)

Rain Alarm Project

Water is basic need in every one’s life. Saving and proper usage of water is very important. Here is an easy project which will give the alarm when there is rain, so that we can make some actions and save the rain water. As a result, we can increase the water levels of underground water by using underwater recharge technique. Rain water detector will detect the rain and make an alert; rain water detector is used in the irrigation field, home automation, communication, automobiles etc. Here is the simple and reliable circuit of rain water detector which can be constructed at low cost. Rain Alarm Project Block Diagram: Rain water sensor is the main component in the circuit. For this rain sensor, no need to go and buy in the market or online. We can do it ourselves just by taking the piece of Bakelite or mica board and aluminum wire. Bakelite or mica board should be made completely flat and aluminum wire should be pasted on the flat board as shown in the figure below o

Motion Detector Circuit

Introduction to Motion Detector: The motion detector is not only used as intruder alarm but also used in many applications like home automation system , energy efficiency system, etc. The motion detector will detect the motion of the people or objects and give the appropriate output according to the circuit. In general, motion detector uses different types of sensors like Passive infrared sensor (which will detect the motion of the person using the person body heat), microwave sensor (Microwave sensor will detect the motion of person by measuring the change in frequency from the produced beam), ultrasonic sensor (It produces acoustic signals which will detect the motion of a person) etc. There are some motion detectors which will use different technology and include number of sensors (PIR, microwave sensor, ultrasonic sensor, etc.) to reduce the false triggering and increase the accuracy in motion detection. Here is the simple and reliable circuit which uses IR sen