HeadPhones : Working and Structure

Headphones or "head-phones" in the early days of telephony and radio are a pair of small  loudspeakers that are designed to be held in place close to a user's ears. They are also known as earspeakers, earphones or, colloquially, cans. The alternate in-ear versions are known as earbuds or earphones. In the context of telecommunication, a headset is a combination of headphone and microphone. Headphones either have wires for connection to a signal source such as an audio amplifier, radio, CD player, portable media player,mobile phone, electronic musical instrument, or have a wireless device, which is used to pick up signal without using a cable.

Structure of the headphone and its working

The headphones here too follow the conventional structure. However, the part that bears the boom for microphone has a slight difference as an extra cable for it is attached into it.

The left section of the headset houses the microphone and one half of the speaker set. When the speaker section of the headphone is opened, the wiring coming from the headphone jack can be seen soldered to the driver of the speaker section.  The wire coming from the microphone jack doesn’t form any connections to the internal circuitry. The copper wire in a thin plastic covering in the image above is that of the microphone. Instead, the wiring from the jack of the microphone simply extends to the microphone

Right part of the Headset merely houses the headphone circuitry and is not having any extra wire for microphone. A single wire which connects the left and right headphones is placed in the groove of the plastic band.

Arduino Based Security System using GSM & PIR Sensor

In present time Home/Office and many other place security is most important. In our absence these places are not secure. For make these palaces secure many peoples keep guards and many people prefer electronic security systems. In present time many types of security systems are available in market. These security systems are very accurate and easy to control and cheaply available and the most important thing is that they can be operated on low Voltage (Up to 12 Voltage). 

In most of security systems GSM is widely used. Here in this project GSM is used for making a voice call for alert. The main aim of this project is secure your house/office from thief.In this circuit GSM and PIR sensor sensor are used. When any human (thief) comes in the range of PIR sensor, Arduino make a call to a fixed number. It means anybody in your house/office, then you can take a possible action against thief at same time.

This system is very simple. And the working of this system is very simple as well. In this system PIR sensor used for sensing and then arduino used for controlling and then A GSM module which is used for calling purpose. When anybody comes in range of PIR sensor, then sensor sends a logic signal to Arduino then Arduino take control and perform a given task. Here a calling task is given to Arduino. Then arduino sends signals to GSM module for make a voice call.

As we know that GSM module works on AT commands so Arduino sends AT commands to GSM module to make a call. To make call AT command is given below:

ATD<Mobile Number>;

If human body is moving in range of PIR sensor, its sends signal to Arduino continuously and Arduino make call again and again until Moving body comes in rest and until goes out of range