Cassette Player

INTRODUCTION:

In this project I am going to make a Compact cassette Player. A cassette player is a system that is used to reproduce the recorded audio on the compact cassette. The cassette player also known as magnetic reproducing system. But in modern time people use micro-SD cards, Pen-Drives, CD, DVD and hard discs to record audio, video and or to save documents.

COMPACT CASSETTE:

Compact cassette is a magnetic cassette that was developed by the Dutch company royal Philips in Hasselt Belgium by Lou Ottens and his team. It was introduced in September 1963. Compact cassette comes in two forms either already containing content as a pre recorded cassette, or as a fully recordable “blank” cassette. Both forms are reversible by user. The compact cassette enclosed two small reels of 1/8 “ tape in a durable, compact, and portable plastic shell 4” X 2.5” X 0.5”. It is safe to say that cassette operates at a low speed of 4.76 cm/s or 1 7/8 IPS (Inches per second). The compact cassette plays or records 30 or 45 minutes of audio per side (C60 and C90 formats respectively), 120 minutes also available.

MAGNETIC HEAD:

A magnetic head is a transducer that converts the electrical signal into a magnetic field. In audio tape recorders or cassette players four types of magnetic heads are used.

1. Play Head
2. Record Head
3. Erase Head
4. Record/play Head

Here in this project I am using only Play Head. When the magnetic tape slides below the play head it produces an induced EMF in the winding of Play head and this induced EMF or voltage is amplified by the pre amplifiers and then it is given to Power amplifiers and then Loudspeakers

The cassette player can be divided into two parts. 1- Cassette Mechanism 2 - Electronic Part

Cassette Mechanism:

The cassette mechanism is used to slide the magnetic tape below the play head. A simple cassette mechanism has three buttons on it.

1 –Stop 2- Play 3- FFW (Fast Forward)

1. Stop Button – This button is used to stop the cassette player.
2. Play Button – Play Button is used to Play the Audio.
3. Fast Forward – This button is used to rotate the magnetic tape forward and fast manner without playing the audio.

Electronic Part:

This part uses electronic technology to reproduce the audio recorded in the magnetic cassette. In this cassette player I am going to use two integrated circuits (ICS) to built the electronic circuit. The first IC is KA22134. which is most popular for using in cassette players. This IC is manufactured by Samsung. and it consists of two pre amplifiers two amplify left and right voltage of play head, two power amplifiers to drive stereo headphone and volume control with a single mono potentiometer.

Motor speed control:

The speed of the motor used in cassette mechanism can be controlled using a second IC i.e. KA2402 and it is always used with KA22134. The speed of motor can be adjusted by a 10k potentiometer on the circuit. There is an another IC available in the market that is most popular for motor speed control and this is AN6650. This IC is manufactured by Panasonic Corporation Japan. You can also use AN6650 instead of KA2402