The invention provides a dimmable light-emitting
diode (LED) driving power supply, comprising an electromagnetic-interference resisting unit, a rectifying unit, a current transforming unit, a
silicon-controlled unit, a dimming unit and a strobing resisting unit. The strobing resisting unit comprises two diodes, a resistance-
capacitance network, a
voltage follower, a
transistor and a field-effect
transistor; the anodes of the two diodes are connected with the
silicon-controlled unit, and the cathodes of the two diodes are connected with the drain
electrode of the field-effect
transistor and are also connected with one input end of the
voltage follower through the resistance-
capacitance network; the other input end of the
voltage follower is connected with the output ends of the diodes; the source
electrode of the field-effect transistor is connected with the collector
electrode of the
triode through the resistance, and the collector of the
triode is connected with the ground; signals output by the voltage follower are used for controlling the work state of the
triode; and when the conduction angle of the field-effect transistor decreases and is in the
wave trough, the triode is fully conducted with the field-effect transistor to maintain the
conduction current of the
silicon-controlled unit, thereby ensuring the silicon-controlled unit to be in the conduction state and preventing the silicon-controlled unit from being conducted repeatedly to strobe.