1.Outline
A tape player consists of the circuit that converts the music or voice recorded on the magnetic tape as a magnetic signal into electrical signal (playback) and the mechanism that drives the tape. The basic construction of the tape player can play the music in the stereo sound like FM broadcast. Many tape players are units equipped with an amplifier, AM/FM radio, CD, etc.
2.Operation of tape player
Music or voice is converted into electrical signal by a microphone and is input in the tape player.
The tape player records the electrical signal on the cassette tape as a magnetic signal. When playing this recorded cassette tape on a tape player, the magnetic signal of the cassette tape is converted into an electrical signal. This signal is amplified by the amplifier and sent to the speaker and output from the speaker as music or voice.
Principle of Recording and Playback
1.Playback
Playback occurs in the reverse order but using the same mechanism as recording.
Making the recorded magnetic tape contact with the playback head and pass through it at a constant speed same as the recording speed produces an electromotive force according to the magnetic force and direction of the magnetic material on the coil of the playback head. The signal wave of the electromotive force becomes the same as that of the sound signal at recording.
This signal is amplified by the amplifier and sent to the speaker and output as music or voice sound.
2.Tape loading mechanism of the tape player
To correctly playback the recorded sound, it is necessary to load the cassette tape at a constant speed (4.76 cm/second).
The mechanism of loading a cassette tape at a constant speed is rotating the capstan at a constant speed, pinching the tape with the rubber roller (pinch roller), and pulling out the tape from the reel on the supply side. A brake is applied to the supply reel and back-tension is also applied so as not to loosen the tape. The take-up reel has to take up the tape sent by the capstan without creating slack. However, since the rotational speed of the take-up side changes according to the taken-up quantity, the clutch transmits the rotation to the take-up reel while the motor turning force is slipped so that the tape is wound at a constant speed.
Automotive Cassette Tape
Outline
There are various types of cassette tapes as shown on the left side. To use the tape performance effectively, it is necessary to switch the equalizer (correction device) in the tape player.
The type of cassette tape is shown on the cassette body, but it is distinguished by the detection hole. When a cassette tape is inserted into the slot, the tape player automatically detects and switches the equalizer circuit.
Handling Tape and Tape Player
1.Maintenance of tape player
When the tape player is used for a long time, the magnetic substance particles from the tape, foreign matter, dust, etc. adheres to the parts such as the capstan and pinch roller that contacts the tape.
As a result, the head or pinch roller cannot fully contact the tape, resulting in a loss of high-frequency response, poor sound quality, or wow flutter. To prevent these problems, clean the tape loading parts from time to time with a cleaning tape. Keeping tapes clean is necessary.
2.Handling tape and tape player
To prevent the decrease of the tape performance or trouble caused by a cassette tape itself, it is necessary to pay attention to the followings:
(1)When a tape is not in use, store it in its case.
(2)Use cassette tapes less than C90 (for 90 minutes).
C120 (for 120 minutes) cassette tapes are extremely thin and liable to stretch, resulting in bad sound quality.
(3)Always keep the tape tightly wound. If it becomes slack, it will not play well.
(4)Be sure to handle only the cassette body. Do not touch the tape itself.
Tape could become dirty, causing poor sound quality.
(5)Do not use a cassette tape whose label is likely to peel off. The label could peel off in the tape player or result in poor loading or difficulty in ejection.
(6)Do not store tapes in the following conditions
High temperature and high humidity
Dusty locations
Locations where strong magnetism is produced (near a TV or speakers)