Select Channel Instead of Changing Cassette
MAGNETIC TAPE RECORDER – PLAYER TO RECORD AND RETRIEVE MULTIPLE MODULATED ELECTRICAL SIGNALS ON MAGNETIC TAPE.
This invention relates to recording of information on magnetic tape and retrieving the recorded information from magnetic tape. Present method of recording information on magnetic tape is: the information is converted into an electrical signal. The electrical signal is amplified and then fed to a magnetic writing head that converts the electrical signal into magnetic field corresponding to the signal. These tiny magnetic fields are stored on a tape coated with magnetic material. Passing the magnetic tape over reading head retrieves the information, which is then amplified and played back.
Invention (What is New)
Recording: The invention is recording more than one information signals on a magnetic tape by modulating different carrier frequencies. All carriers are recorded together as a mixture signal.
Retrieving: A playback head reads the mixture. An adjustable tuning circuit selects one carrier, which is then amplified and demodulated to recover the original information signal. Either AM or FM modulation can be used.
Explanation: S1, S2, S3 are sources; 1,4,7 are amplifiers; 2,5,8 are modulators; 3,6,9 are carrier generators. Block 10 mixes outputs to record on tape.
Block Diagram for Retrieving
Playback head → amplifier → tuning circuit → demodulator → amplifier → output device.
