Purpose: program-controlled switches copy machine washing machines refrigerators cameras sterilized kitchen cupboards door magnetic magnetic window electromagnetic relays electronic weighing apparatus level meter gas meter water meter and so on got very good application. Adopt imported normally open type dry reed pipe. Comparator output signal clean good waveform driving ability is strong for more than 15mA. The working voltage is 3.3~5 V. Output: digital switch output (0 and 1). Fixed bolt hole convenient installation. Use the LM393 wide voltage comparator. The characteristics of the dry reed pipe: dry reed pipe is short for dry reed pipe there is a contact of passive electronic switch components has the advantages of simple structure the advantages of small size is easy to control its shell is commonly a sealed glass tube tube is equipped with two elastic reeds iron panels poured a kind of metal rhodium inert gas. At ordinary times two of the glass tube made of special materials reeds are separated. When the magnetic material near the glass tube under the action of magnetic field lines the two reed pipe is magnetized and attract each other contact reed will suck together make the circuit connected nodes receive. Module uses: dry reed pipe need magnet and at the time of induction to have certain magnetic will show conduction state module output low level no magnetic show off state output high level dry reed pipe and magnetic induction distance within 1.5 cm beyond insensitive or will not trigger phenomenon; Module can DO output microcontroller I/O port directly connected triggered by single chip microcomputer can detect dry reed pipe status;Modules DO output and relay connected IN end composed of high power dry reed pipe switches control of high voltage directly.