ivar
Junior Member level 1
I want to power my microcontroller board using a 7805 (which receives input power via a DC adapter) and a USB port. Assuming only one of these power sources is active at a time, can i just tie the output of the usb and the 7805 together without using a jumper to select the appropriate power? If I tie the outputs together and use the USB, the OUTPUT pin of the 7805 will be subject to 5V. Is that a problem?