과전류 보호 가란 무엇입니까??

과전류 보호는 구성 요소 손상을 방지하기 위해 설정 임계 값을 초과하는 전류를 감지하고 제한하는 데 사용되는 회로 보호 메커니즘입니다., 과도한 전류로 인한 안전 위험 또는 시스템 불안정성. 다음은 과전류 보호에 대한 자세한 분석입니다:

1. ‌Basic concept‌
Overcurrent protection monitors the current value and triggers the protection device to operate (such as tripping or alarm) when the current exceeds the preset maximum value, thereby cutting off the fault circuit or reducing the risk. Its application scenarios include:

Short 회로 보호 ort: For instantaneous large currents (such as direct contact of wires), 빠른 반응 (microsecond level) is required.

wprotever 보호 ‌: For continuous over-rated current, an inverse time delay mechanism (such as thermal relay) is usually used.

2. working 원칙 princip
‌Current detection‌: Real-time monitoring of current through sampling resistors, current transformers or integrated ICs (such as LT6100).
‌Trigger mechanism‌: 전류가 설정 값을 초과하는 경우, the relay or circuit breaker operates and the circuit is disconnected.
‌Delay design‌: It is divided into three-stage protection (fast break, time-limited fast break, and time-limited overcurrent), taking into account selectivity and response speed.

3. ‌Implementation method‌
‌Discrete components‌: Such as a simple circuit built with a transistor + sampling resistor, which limits the current by clamping the voltage (예를 들어, a 1A threshold design).
‌Integrated solution‌:
‌PTC resettable fuse‌: The resistance value increases sharply when overcurrent occurs, and it automatically resets after the fault is eliminated.
‌Special protection IC‌: Such as the overcurrent, overvoltage, and overheating multiple protection circuits in the DC power conversion chip.

4. ‌Technical parameters and selection‌
‌Rated current/voltage‌: It needs to match the load requirements (such as 3A~25A, 125/250VAC).
‌Action time‌: Short-circuit protection needs to be ≤40ns, and overload protection can be delayed to seconds.
환경 적 적응성 ‌: Consider the influence of conductor cross-sectional area and temperature on current carrying capacity.

5. Application Cases

Power system: Three-stage protection covers the entire length of the line and the backup area.

전자 장비: 예를 들어, USB interface overcurrent protection prevents the motherboard from burning out.

Industrial motor: Combines multiple protection functions such as stall and phase failure.

The core of overcurrent protection is to balance sensitivity and selectivity, ensuring accurate fault isolation while avoiding false operation.