Reed is dry reed short, is a kind of passive electronic switch contact element has a simple structure, small size and easy to control, etc., the shell is generally a sealed glass tubes are installed there are two flexible iron reed panels, also called metal rhodium has a filling of inert gas. Normally, two glass tubes made of special materials reeds are separated. When a magnetic substance near the glass tube, under the action of magnetic field lines, the two reed pipe is magnetized and attract each other contacts, the reed will pull together to make a circuit of the connected node communication. After the disappearance of the external magnetic force, two reeds separately because of their elasticity, the line also disconnected. Therefore, as a signal to control the use of magnetic field lines switching devices, the reed can be used as a sensor for counting, spacing, and so on (in the security system is mainly used for door sensor, window magnetic production), but also It is widely used in a variety of communication devices. In practice, usually with a permanent magnet control the two metal sheets turned on or not, it is also known as "magnetron." Features: Imported normally open reed The comparator output signals clean, good waveform, driving ability, than 15mA. The output form: digital switching output (0 and 1) A fixed bolt hole for easy installation Small PCB board size of 3.2cm x 1.4cm Using a wide voltage comparator LM393 Application: SPC exchange, copy machine, washing machines, refrigerators, camera, disinfect cupboard, door magnetic, magnetic window, electromagnetic relays, electronic weighing apparatus, level meter, gas meter, water meter. Specification: Working voltage of 3.3V-5V Type:Normally-open Comparator : LM393 Output Type : Digital output (0 and 1) PCB board size: 3.2*1.4cm/1.3*0.6in Weight: Approx.13g/0.5oz Module USES: 1. The dry reed pipe need magnet, when sensing certain magnetic force, will show ON state, the module output low level; no magnetic, show OFF state, output high level, dry reed pipe and magnetic induction distance within 1.5 cm, beyond this distance ,insensitive or will not trigger phenomenon; 2. The module DO output end can connect directly to microcontroller I/O port, triggered by single chip microcomputer can detect dry reed pipe status;it can detect the trigger state of the dry reed by SCM 3. Modules DO output end connect the IN end of relay, can compose high power dry reed pipe switches, control high voltage directly. Package list: 4 x Reed module