Circuit break basics – another teaching moment video from Digi-Key Electronics

Sponsored content

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.

Without the protection of an overcurrent circuit breaker, downline components, wires and PCB (printed circuit board) traces may fail, resulting in costly or time-consuming repairs. Today on Another Teaching Moment, learn about the wide variety of circuit breaker types and how they function.

The different kinds of circuit breakers that are covered include:

Magnetic

• Not temperature sensitive
• Voltage sensitive – can’t cross DC model with AC model
• Uses a 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