Coin-operated telephone with a microprocessor

摘要: The coin-operated telephone with a microprocessor (5), meter pulse receiver (6) for the pulses arriving from loop, detector (3) loop current, changeover switch (4) disposed at output of this and hook contact (GK) power supply (11) has memory (7) electronic logic circuits (9, 10, 12 14) which, if (5) is affected by interference due to spurious or deliberate intervention, reset so that it runs its program disconnects line (1). 12, are activated not booked, feed voltage (V1) (7, 9, fails disconnected (1) following local charge-free call.