Detektorschaltung fuer Fernsprechnetze

摘要

The detector circuit for determining call data in telephone networks can be connected in parallel with the subscriber loop and in each case has one input circuit (1 or 2) which effects DC isolation for each polarity of the telephone loop and which is connected via delayed toggle circuits (13, 14 or 15, 16) with two different toggle levels to a logic circuit (17) which has three outputs, of which the first output carries a signal g indicating the presence of the loop current, the second output carries a signal h indicating the ringing current and the third output carries a signal i indicating the polarity change. The logic circuit (17) can be formed with a microprocessor with programmable logic. <IMAGE>