Single-stage isolated converter supporting direct current source input

The invention discloses a single-stage isolated converter supporting direct current source input. The single-stage isolated converter comprises a conversion circuit, a voltage conversion circuit, a controller, an auxiliary power supply circuit and a pre-charging circuit. According to the invention, by arranging the controller, when the output voltage fluctuates, the duty ratio of the switch tube can be controlled through the controller so as to control the output voltage, so that the output voltage is made to be fast and stable, and the stability of the output voltage is improved; and by arranging the pre-charging circuit and the auxiliary power supply circuit, when the converter is started, the first voltage stabilizing tube in the pre-charging circuit is broken down and then supplies power to the auxiliary power supply circuit, and when the converter works stably, the pre-charging circuit does not work and the auxiliary power supply circuit works, so that thevoltage stabilizing tubein the pre-charging circu