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Musical Instruments of C.D.(Compact Disk) type using light signals


  1. Photo transister TPS 601 or TPS 603 (Japanese Industrial Standard)
  2. Resister 10 kΩ or 5 kΩ
  3. Capacitor 0.1μF or 0.05μF
  4. Mini plug (φ 3.5mm) of monoral type or stereo type
  5. Two electric batterys (1.5V) and their holders
  6. Barret of a ball point pen or pipe of the same size

Notes for production

  1. You can use either photo transister, TPS 601 or TPS 603 as you like.
  2. You must connect the positive side of the electric batterys with the collector of the photo transister.
    If you do so, resistance between the collector and the emitter
    of the photo transister will grow down about 1 kΩ in the light. Please make sure of it.
  3. How to connect the parts.

  4. You can cut the direct voltage with the capacitor 0.1μF or 0.05μF, and it protects your taperecorder, sending only A.C. signal to the microphone terminal.

How to play this musical instrument

  1. You stick the disk on a turning table and turn it round with a certain velocity.
    You shine the patterns with a �@flash light (D.C. type)(natural light is all right).
  2. You play the melody with the photo transister,catching the patterns lighted up according to the melody.

referece "Lively Physics and Thrilling Experiments 2" Revised Edition published by Hyoronsha in Japan March 25, 2002

Pattterns for musical instrument CD type
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