PWM speed regulation circuit with overload protection and speed regulation device

The utility model relates to the technical field of cooling fan control, and particularly discloses a PWM speed regulation circuit with overload protection, which is used for being connected between aPWM control signal and a fan and comprises a driving unit, a filtering unit, an output unit and an overload protection unit. The driving unit is used for intermittently outputting the direct currentsubjected to current amplification outwards according to the duty ratio of the accessed PWM control signal so as to drive the fan; the output unit is used for inputting direct current into the fan; the filtering unit is used for carrying out output filtering on the direct current; and the overload protection unit is connected between the negative electrode of the output unit and the driving unit and used for monitoring the current intensity on the fan, and if the current intensity is higher than the rated current intensity of the fan, the driving unit is controlled to stop driving the fan. Theutility model further disc