A time-delay soft start circuit used for BOOST-PFC

The utility model relates to a time-delay soft start circuit used for BOOST-PFC. A driving time-delay circuit and an on-off control terminal are added on the basis of background technology. After closing and time-delay of a relay, driving begins so as to realize a normal output of the BOOST-PFC. Driving for the soft start relay and a chip is switched off after shutdown is carried out. The control chip is enabled to output driving after the relay is closed and performs time-delay for a certain time, so that overheating of a soft start resistor will not occur.