| 摘要 |
A wound-tape radius detecting system for use in reel to reel audio and video tape decks includes first and second photoelectric devices which act as supply or take-up reel and tape transport tachometers, resepctively. The ratio of the pulses outputs of the two photoelectric devices are indicative of the amount, or radius, of tape on the supply or take-up reel, which information can be used to control the braking torque applied to the reels when the tape deck is stopped, or the reel motor torque at the start of transport.
|
