Permanent magnet detector

The utility model relates to a permanent magnet detector used for detecting permanent magnets. The detector is formed by that an inductor of the magnetic field, a filter, a pulse voltage amplifier, a pulse amplifier, a pulse memory and time-delay releaser, a triggering amplifier of the electrical level and an alarm device are connected in sequence. The utility model can detect whether the permanent magnet exists and the strength of the magnetic field of permanent magnet, and thus the things in the various locations such as in the markets, libraries and reading rooms can prevented from being stolen effectively.