Magnetic Inductive Switch
Use the magnet or test coil to form a magnetical environment to effect trigger switching. This is very inventive application. There are options of metal Magnetic Inductive Switch, ABS Magnetic Inductive Switch. Here you can have your ideas come true for the Inductive...
Magnetic Inductive Switch
Use the magnet or test coil to form a magnetical environment to effect trigger switching. This is very inventive application. There are options of metal Magnetic Inductive Switch, ABS Magnetic Inductive Switch.
Inductive proximity switches are a low-cost method for non-contact detection of metal objects. When a metal object is moved toward or away from a proximity switch, the signal will automatically change to achieve the purpose of detection.
The inductive proximity switch consists of an lc oscillation circuit, a signal trigger, and a switching amplifier. The coil of the oscillation circuit generates a high-frequency variable magnetic field that is released via the sensing surface of the sensor. When the metal material is close to the sensing surface, if it is a non-magnetic metal, a vortex current is generated. If it is a magnetic metal, hysteresis and eddy current loss will also occur. These losses will reduce the energy of the lc oscillation circuit and reduce the oscillation. When the signal trigger detects this reduction, it will convert it into a switching signal.
Proximity switches should not interfere with each other. Therefore, a must be kept at a minimum distance between two proximity switches. This distance a depends on the size and type of the proximity switch. Connector The cylindrical version is equipped with an 8 mm modular plug or a standard plug (3 or 4 pole) with m 12 threads. A cable head is also required for the plug-socket connection. Plugs (3 poles) with m 18 threads are also available for the m 18 and m 30 models. Cables Generally use polyurethane (pur) oil-resistant skin high-flexible cable with a standard length of 2m. For applications where the cable comes in contact with acids or bases, order devices with pvc cables. For devices used in applications that meet ul and csa requirements, pvc cables must be ordered. Cable length For proximity switches, long cables can cause: Capacitive load on the output Increased interference injection Even under favorable conditions, the cable length must not exceed 300 m. Cable laying The connection wires of the proximity switches should not be placed in cable ducts beside the cables used to switch inductive loads (such as contactor coils, solenoid valves, motors) or to carry current for solid-state motor drives. Keep the cable length as short as possible. The cable length can be up to 300 m under favorable wiring conditions (less coupling and interference voltages). You can reduce the interference by the following measures: Clearance gaps with interfering cables Use rc elements or variable resistors to connect coils (contactors, relays or solenoid valves).
THE WORKING PRINCIPLE OF PROXIMITY SWITCH
Hall switch operation principle
First, the principle of introduction When a current through the metal or semiconductor sheet vertically placed in the magnetic field, the potential difference between the two ends of the sheet, this phenomenon is called the Hall effect. The potential difference between the two ends is called the Hall potential U, and the expression is that K is the Hall coefficient, I is the current passing through the slice, B is the magnetic induction intensity of the applied magnetic field (Lorrentz), d is The thickness of the sheet. It can be seen that the sensitivity of the Hall effect is directly proportional to the magnetic induction intensity of the applied magnetic field. The Hall switch belongs to such an active magnetoelectric conversion device. It is based on the Hall effect principle and is manufactured using an integrated package and assembly process. It can easily convert magnetic input signals into electricity in practical applications. Signals, at the same time, have the requirements of practical applications for easy operation and reliability in industrial applications. The input of the Hall switch is characterized by magnetic induction B. When the B value reaches a certain level (such as B1), the internal switch of the Hall switch is turned over, and the state of the output level of the Hall switch is also reversed. The transistor output is generally used at the output end. Similar to the proximity switches, there are NPN, PNP, normally open, normally closed, latched (bipolar), and dual signal outputs. Hall switch has the characteristics of no electric shock, low power consumption, long service life, high response frequency, etc. The internal use of epoxy sealing and integration, so it can work reliably in all kinds of harsh environments. Hall switches can be applied to proximity switches, pressure switches, odometers, etc. as a new type of electrical accessories.
Second, the internal schematic
Proximity switch classification and structure
The function of the proximity switch is to send a signal when an object approaches the proximity switch and reaches a certain distance. It does not require the application of external force, is a non-contact main commander. Its use has far exceeded the trip control and limit protection provided by the trip switch. Proximity switches can be used for high-speed counting, detection of the presence of metal bodies, speed measurement, level control, detection of part sizes, and use as contactless buttons. At present, the widely used proximity switches can be divided into the following types based on the working principle:
High-frequency oscillation type: used to detect various metal bodies
Capacitance type: used to detect various conductive or non-conductive liquids or solids
Photoelectric type: used to detect all opaque substances
Ultrasonic type: used to detect substances that do not transmit ultrasonic waves
Electromagnetic induction type: used to detect magnetic or non-magnetic metal
According to its shape, it can be divided into cylinder type, square type, channel type, perforation type and separation type. Cylindrical type is easy to install, but its detection characteristics are the same. The groove type detection part is inside the tank. It is used to detect the objects passing through the tank. The penetration type is rarely produced in our country, while in Japan it is more common and can be used. Small parts such as small screws or balls and buoys are assembled into water level detection devices.
Proximity switch can be divided into direct current type and alternating current type according to power supply. According to output type, it can be divided into direct current two-wire system, direct current three-wire system, direct current four-wire system, alternating current two-wire system and alternating current three-wire system.