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AISSUE

Your AISSUE, our solutions.

Tag: Control

  • What circuit design issues need to be paid attention to when using PWM to control a motor?

    What circuit design issues need to be paid attention to when using PWM to control a motor?

    A common question with circuit design is “What should I pay attention to when controlling a motor with Pulse-width modulation (PWM)?”

    If you want to use PWM to control the motor action, it is generally referred to as a DC motor.

    If you want to use a relay to control it, it will definitely not work, because the round trip time of the mechanical structure is too long, as long as the frequency is high, it will not act, and the mechanical structure will be broken if the life is not high.

    In the worst case, optocoupler isolation IC+BJT should be used to amplify the current to control.

    But in fact the best choice is to use a high-power transistor (Power MOSFET) for control.

    Of course, you can choose the built-in PWM module of the motor itself. If you use a single chip to implement PWM, you need to pay attention to whether the output current of the pin is enough to drive. Generally, the traditional 8051 IC can supply 15mA, while the new Arduino can reach 20-30mA.

    When designing a PWM-controlled motor circuit with a single chip, special attention should be paid to electrical protection and power pollution issues.

    The former is because the PWM operation itself will generate a back electromotive force, which can be protected by the design of the transistor circuit.

    Power pollution is due to the current feedback from the motor startup, which may crash the chip and cause a crash, which can be protected by the circuit design of voltage regulation and power isolation.

  • Inbound Epidemic Prevention!Simple classification of animal and plant product control

    Inbound Epidemic Prevention!Simple classification of animal and plant product control

    The recent spread of African swine fever and Japanese swine fever in mainland China has led China to strengthen its advocacy to ban the carrying of pork and its processed products into the country, and to strengthen animal and plant epidemic prevention work in the Customs channel and increase the amount of punishment.However, as early as December 25, 95, the Executive Yuan has sent a letter to the Agriculture Committee requesting that in order to safeguard the health of the people, protect the domestic ecology and the needs of epidemic prevention and quarantine, it is necessary to restrict inbound passengers from carrying animals and plants and their products on the basis of January 1, 96, and to do so in accordance with the instructions.

    The following three key points are mainly highlighted in the official letter “No. No. 0950094817 of the Court”, which includes:

    • Requests the Civil Aviation Bureau of the Ministry of Transport to co-ordinate the broadcasting of inbound airlines on board the aircraft and to ask the aircrew to inform inbound passengers that those carrying flora and fauna and their products should complete the customs declaration form and inspect the customs clearance through the red Line counter.
    • The Agricultural committee of the hospital is requested to coordinate the Taoyuan International Airport Air Station and, without affecting the movement of passengers, to set up abandoned boxes for agricultural and livestock products, and to actively dispose of the animals and plants and their products brought in by the inbound passengers.
    • The Agricultural committee of the hospital is requested to move the quarantine operation counter to the vicinity of customs clearance cabinets to facilitate the implementation and coordination of quarantine and preventive operations and customs inspection.In order to enhance the effectiveness of implementation, the Ministry of Finance is requested to coordinate customs officers with the quarantine detection Dog team of the animal and plant epidemic prevention and Quarantine Bureau, and to jointly carry out the verification of the carrying of animals and plants and their products by inbound passengers at the Customs clearance Office and the Customs Inspection cabinets

    In addition, an official document providing a list of animals and plants and their products to control inbound passengers can be used to identify, on a large scale, which animal and plant products are prohibited from carrying entry, and passengers can also use them to quickly check the availability of related products in their carry-on or checked baggage, including:

    • Living animals and their products.
      • Exclusions: dogs, cats, rabbits and animal products that comply with the regulations for the prevention and control of animal infectious diseases.
      • After drying, processing modulation of aquatic products.
    • Living plants and their fresh products.
      • Exclusions: Those who comply with the provisions of the phytosanitary Law on plant epidemic prevention.
    • Fresh fruit.