Led drive circuit and led lamp

An LED lamp, comprising a LED drive circuit and at least one LED connected with the LED drive circuit, wherein:

• the LED drive circuit comprises a feedback control circuit and a load impedance increasing circuit, wherein the feedback control circuit acquires operating current of an LED, compares the operating current with a default threshold, drives the load impedance increasing circuit to operate when the operating current of the LED is greater than or equal to the threshold, and allows the load impedance increasing circuit not to operate when the operating current of the LED is less than the threshold;
• and the load equivalent impedance of the LED drive circuit is increased when the load impedance increasing circuit operates;
• and
• the LED drive circuit is configured to drive the at least one LED to emit light after power-on.

A method of utilizing a light-emitting diode (LED) drive circuit, comprising:

• acquiring, by a feedback control circuit, operating current of an LED,
• comparing the operating current with a default threshold,
• driving a load impedance increasing circuit to operate when the operating current of the LED is greater than or equal to the threshold,
• allowing the load impedance increasing circuit not to operate when the operating current of the LED is less than the threshold, and
• increasing the load equivalent impedance of the LED drive circuit when the load impedance increasing circuit operates.