Keyboard a manual actuation of the electrical contacts and a reading of its state, from among four possible states

摘要

Keyboard a manual actuation of the electrical contacts and a reading of its state, from among four possible states. / p & & p & keyboard a manual actuation of the electrical contacts and a reading of its state, from among four possible states, characterizes in that the keyboard is a dipole between the terminals 2, 3 which are arranged in parallel, three links, each comprising one of said electrical contacts 4, 5, 6, two of these links including diodes 7, 8 montees head - spade, so that its various states may be victims of discrimination by successive application of two opposite electrical voltages v1, v2 across the terminals of the dipole and detection corresponding logic.