I'm developing a project using TWR-K70 development board and the TWR-LCD-RGB. I need to use the screw terminal to supply the system, because in my final product I will not have access to a USB port.
What I'm doing right now is supplying the system with a DC power supply. This needs to be high due to the other circuits I'm using, so it is around 18 to 24 volts. I'm using several stages to diminish this voltage to 5 volts using linear voltage regulators. However, these are getting really hot and suddenly the LCD is not getting enough current and turns down. I'm not sure why this is happening because apparently the system is using only 480 mA and the different regulators I'm using (LM7815, 7812, 7809 and 7805) are capable of supplying twice this current.
Is there any recommended supply system for this issue?