Overcurrent protection circuit with automatic latching function

Abstract

The invention discloses an overcurrent protection circuit with an automatic latch function. The circuit comprises a feedback control module, a main control switch module and a current detection module which are connected in sequence, a filtering unit is connected with a power supply to output electric energy to the main control switch module, and provides stable voltage for a load, ,the feedback control module is used for receiving a signal of the current detection module and controlling the on-off of the main control switch module, the main control switch module is connected with a power supply and controls the on-off of the power supply, the current detection module is used for detecting the current of a load circuit and transmitting the signal to the feedback control module a latch unit is also arranged between the feedback control module and the main control switch, and the latch unit is used for latching a control signal output by the current detection module to the feedback control module; intelligent triggering of over-current signals is achieved through PN junction attributes of a base electrode and an emitter electrode of a triode and a detection resistor, the response time is short, and the reliability is high. The current detection sensitivity and the over-current threshold value can be adjusted through the detection resistor.

Description

technical field [0001] The invention relates to the field of overcurrent protection, in particular to an overcurrent protection circuit with an automatic latch function. Background technique [0002] Overcurrent protection refers to a protection method that makes the protection device operate when the current exceeds a predetermined maximum value. When the current flowing through the protected element exceeds a pre-set value, the protection device is activated to trip the circuit breaker or give an alarm signal. If the overcurrent protection device is not installed, once the current in some circuits is too large due to short circuit or abnormal components, it is easy to burn out the components, especially in some circuits that are sensitive to current changes. It may even cause a fire accident due to excessive current, so it is necessary to set up an overcurrent protection circuit. However, the existing overcurrent protection device responds more accurately to changes in l...

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Problems solved by technology

If the overcurrent protection device is not installed, once the current in some circuits is too large due to short circuit or abnormal components, it is easy to burn out the components, especially in some circuits that are sensitive to current changes. It may even cause a fire accident due to excessive current, so it is necessary to set the overcurrent protection circuit

However, the existing overcurrent protection device responds more accurately to changes in large currents, but responds slowly to relatively small overcurrents or e...

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