Additional power circuit design for USB devices

Most of the USB devices used today sometimes cause lack of power issues. How do you know the maximum current that can be drawn from a single USB connector is limited to 500mA . If your device requires more current, then it must include an additional USB port, which may not be available. This problem can be solved with an additional tool that uses an external unstable power supply and converts it to 5 volts.

　　There are two different methods you can use. There are two different methods you can use. The first, and maybe the simplest - use a simple linear regulator, but this causes other problems - wasted consumption power, but you can go the other way and use a pulse transformer, which is much more economical.

　　Note: The basis of the converter is a PWM controller based on the LM 2575-5 integrated circuit with an output of 5 Volts up to 1A. Enable/disable the converter using 5-pin on/off, controlled transistor VT 1.