The so-called PNP and NPN proximity switches are for the type of DC three-wire proximity switch output transistor, and even though many proximity switch output stages use MOS transistors, they are still called the same.
Differences: PNP type proximity switch: The type of proximity switch output transistor is PNP, when a sensitive object approaches, the proximity switch is triggered, the output transistor is turned on, and the current flows into the proximity switch output stage transistor through the load, and then enters the ground, which is equivalent to outputting a low-level signal. NPN type proximity switch: The type of proximity switch output transistor is PNP, when a sensitive object approaches, the proximity switch is triggered, the output transistor is turned on, and the current flows out to the load through the proximity switch output stage transistor, and then enters the ground, which is equivalent to the output of a high-level signal.
Different occasions of use: Proximity switches are often used in the same way as PLC inputs. For the PLC with drain input (the input is valid at the low level), the PNP type proximity switch can be directly connected (the common termination of the PLC input is 0V); For the PLC with the source input (the input is active high), the NPN type proximity switch can be connected directly (the common termination of the PLC input is 24V). Both proximity sensors are suitable for Siemens PLCs, but some PLCs can only use proximity sensors of the NPN type.
Proximity switches, also known as contactless proximity switches, are ideal electronic switching sensors. When the metal detector body is close to the sensing area of the switch, the switch can be no contact, no pressure, no sparks, send out electrical instructions, and accurately reflect the position and stroke of the moving mechanism, even if it is used for general stroke control, its positioning accuracy, operation frequency, service life, convenience of installation and adjustment and the ability to apply to harsh environments are incomparable with general mechanical travel switches. It is widely used in machine tools, metallurgy, chemical industry, textile and printing industries. In the automatic control system, it can be used as limit, counting, positioning control and automatic protection link.
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Tianyi switch - a measure to reduce the ripple and noise voltage of the switching power supply
Reduces EMI interference
The metal shell is used as a shield to reduce the interference of external electromagnetic field radiation. To reduce electromagnetic interference from the power line input, an EMI filter is added to the power supply input.
At the output, capacitors with good high-frequency performance and low ESR are used
The use of polymer solids ...
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Tianyi switch - the difference between switching power supply and linear power supply
(1) The cost of linear power supply is higher than that of switching power supply at a certain output power point.
Therefore, with the development and innovation of power electronics technology, the switching power supply technology continues to break through and innovate.
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Tianyi switch - the air switch is always the reason for tripping
1. The current value of the air switch is too low, and the load power is greater than the rated power of the air switch.
2. The load joint is not firm, and the joint is not compressed.
3. If there is a short circuit in the line, check whether the electrical plug is dry.
4. The line is aging and leaking, resulting in both the live wire and the neutral line.
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Tianyi switch - the installation method of the limit switch
1. First open all the packages of the newly bought limit switch, confirm that the parts in each package are not missing and complete, and then discharge all the parts in turn.
2. Then open the body part of the limit switch, as long as you loosen the screws with a screwdriver.
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Tianyi switch - introduction to the characteristics of high-voltage load switch
1. It can isolate the power supply, have obvious disconnection points, and is mostly used for fixed high-voltage equipment.
2. It has an arc extinguishing device and a certain opening and closing speed, and can pass the normal working current and the specified short-circuit circuit in the closing state.
3. It is strictly forbidden to turn on and off the circuit with load.
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Tianyi switch - common faults and treatment methods of switching power supply
First, the repair method
The maintenance of a switching power supply can be carried out in two stages
(1) When the power is cut off, it is "Look, Listen, Listen, Measure"
Look: Open the power box, check whether the wire is disconnected, look inside the power supply, and find that the PCB substrate of the power supply is scorched or the components are cracked.
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New Upgrades - A new member of the warning light family reports
JD series warning light is Tianyi electrical appliances in the field of signal control launched high-performance products, once launched, it has won the unanimous favor of customers, products in the design, manufacturing, quality control and other aspects of the company's quality system has always been under the strict testing and supervision of the company's quality system, to ensure that each product ...
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Where can Tianyi switch - limit switch be used?
daily life
There are many aspects of the use of limit switches, and it is found in many electrical appliances. So what effect can such a simple switch have? It is first and foremost a chain maintenance effect. The most common example is its use in washing machines and tape recorders (video recorders). ...
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Tianyi switch - PCB design considerations for switching power supplies
In the design of switching power supply, the physical design of the PCB board must be proper, otherwise it may cause excessive electromagnetic interference and lead to unstable power supply.
1. The design process from the schematic diagram to the PCB should be rigorous and perfect: the establishment of component parameters ...
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Tianyi switch - the role of the disconnector switch
1. After opening, establish a reliable insulation gap to separate the equipment or line that needs to be overhauled from the power supply with an obvious disconnection point to ensure the safety of maintenance personnel and equipment.
2. According to the operation needs, change the line.
3. It can be used to divide and combine small currents in the line, ...
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Tianyi switch - the characteristics and classification of load isolation switch
First, the characteristics of the load switch
A load switch is a switchgear between a circuit breaker and an isolation switch. It has a simple arc extinguishing device, which can cut off the rated load current and a certain overload current, but cannot cut off the short-circuit current
Second, the classification of load switches
According to the operating voltage ...
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Tianyi switch - the difference between high-voltage load switch and high-voltage isolation switch
1. The high-voltage load switch can be broken with load and has the function of self-extinguishing arc, but its breaking capacity is very small and limited.
2. The high-voltage isolation switch is generally not able to break with load, there is no arc extinguishing cover in the structure, and there is also an isolation switch that can break the load.
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Tianyi switch - how to select the switch?
1. Use less plastic switches
The switch is composed of a panel, a current carrier, a nozzle and a base, etc., and a good switch is mostly made of stainless steel inlay, which is safe and anti-electric shock. On the contrary, most of the inferior switches are made of plastic, although they are insulated, they are prone to leakage and flammability, and potential safety hazards will occur.
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Tianyi switch - an introduction to the common types of low-voltage switches
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Tianyi switch - the reason why the air switch trips and cannot be pushed
1. What is the reason why the empty trip cannot be pushed?
1. If the air opening itself is faulty or damaged, the air opening should be replaced with a new one.
2. If the line is caused by a short circuit, the line should be found first, and then reconnected.
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Tianyi switch - the allowable operating range of the disconnector
1. Pull together the voltage transformer and lightning arrester under normal conditions.
2. Pull together the 220kV no-load bus.
3. The neutral point of the transformer when there is no ground fault in the latching grid.
4. Pull the bypass current that is closed by a switch or an isolated switch.
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Tianyi switch - common faults and troubleshooting methods of low-voltage switches
1 The contact is overheated
Contact heat is mainly caused by the current flowing through the contact, and there is power loss between the contacts (such as contact resistance loss, arc energy loss). It is normal for the contacts to heat up, but severe heat (overheating) is a malfunction.
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Tianyi switch - the method of adjusting the current of Tianyi switch
1. Change the reference current of the feedback module
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Tianyi switch - the model meaning of the proximity switch is introduced
Unmarked/Z: Inductive/inductive self-diagnosis
C/CZ: Capacitive/Capacitive Self-Diagnosis
N: NAMUR safety switch
X: Analog
F: Hall
V: Reed type
J: Threaded cylindrical
B: Cylindrical
Q: Angular cylindrical shape
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VTeam switch – how to operate a linear DC power supply correctly
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2) Constant Current Setting: Connect ...
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