An integral DC to DC converter includes an input capacitor, a DC to AC circuit, a transformer, a rectifying circuit, a filtering capacitor and a control signal generator. The DC to AC circuit is connected with the input capacitor for converting the input DC voltage to a high frequency first AC voltage and the DC to AC circuit includes four full-bridge switching devices. The transformer is used for converting the first AC voltage into a second AC voltage. The rectifying circuit is connected to the secondary winding of the transformer for rectifying the second AC voltage to the output DC voltage. The filtering capacitor is connected to the rectifying circuit for filtering the output DC voltage. The control signal generator is used for providing a control signal to control the full-bridge switching device.