摘要 |
<p>The locking system comprises a magnetic key having a plurality of parallel rows of magnets arranged in a pattern one behind the other and forming a locking code of the magnetic key, and a reading device into which the magnetic key can be inserted in the direction of the rows of its magnets. The reading device comprises magnetic field sensors for the serial reading of the locking code formed by the magnets. A control circuit which compares the information of the read locking code with the information of a predetermined locking code generates a control signal in dependence upon the conformity or difference of the locking codes. At least the magnets of the pattern positions of each row which are immediately adjacent in the row direction are oppositely polarized. For each row of magnets the reading device comprises two magnetic field sensors of which the first magnetic field sensor responds selectively to magnetic fields of a given polarity and the second magnetic field sensor responds selectively to magnetic fields with opposite polarity. The output signals of the magnetic field sensors are OR-linked with one another for the production of a clock signal. In order to prevent tampering in the insertion of the key into the reading device, the clock pulses are counted in the insertion of the key and compared with a predetermined number.</p> |