Basics of Circuit Breakers

I recently wrote an article about circuit breakers and some considerations for choosing a particular model of breaker. No matter how good of a design a device has, it will still be subjected to events that are out of the control of the engineer. From lightning strikes to short circuits, circuit protection can save a lot of money. There are many different kinds of over current situations that can happen, and some are necessary like an inrush current on a motor. Different types of circuit breakers are better for different applications. The article explores three different types of circuit breakers, some of the terminology that is used in industry, and where to find these on the DigiKey website.

Image of TE Connectivity's W51 Series Circuit Breaker

The different kinds of circuit breakers that are covered are:

Magnetic

  • Not temperature sensitive
  • Voltage sensitive – can’t cross DC model with AC model
  • Uses magnetic field to actuate a solenoid to trip breaker when too much current is present

Thermal

  • Temperature sensitive
  • Not voltage sensitive – can cross a DC model with an AC model
  • Uses bimetallic strip to sense temperature change caused by current

Solid State  

  • Replace bimetallic strip and solenoid operation
    • Use current sensor and microprocessor or microcontroller to monitor
  • Much faster response time
  • More expensive

关于此作者

Image of Pat Sagsveen Pat Sagsveen 是 DigiKey 的助理应用工程技术员,负责协助客户寻找更好的利用新技术和新零件的方式来完成项目。他拥有俾斯麦州立大学电子与通信应用科学学士学位,2016 年毕业后即加入 DigiKey。Pat 对放大器特别感兴趣,业余花了很多时间制作和摆弄各种放大器,其中包括他制作的 3 管吉它放大器。
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