K33rg4t3
Full Member level 3
Hey.
I am making a simple circuit that should be powered from 8V+ unregulatred through the 7805 regulator OR through the USB.
I know that I never should connected two power supplies at once.
My question is: Can I connect USB voltage after 7805 (at Vout) and left Vin disconnected? Will it somehow affect the circuit in the bad way, or the 7805 will behave "safe", as diode or something?
Here is the simple schematic, I am aking about this particular case. Is this safe or no, and, why?
PS: I know that the connecting two power supplise at once is bad, I am asking only about this particular case (Vin left disconnected, only 5V from USB connected)
I am making a simple circuit that should be powered from 8V+ unregulatred through the 7805 regulator OR through the USB.
I know that I never should connected two power supplies at once.
My question is: Can I connect USB voltage after 7805 (at Vout) and left Vin disconnected? Will it somehow affect the circuit in the bad way, or the 7805 will behave "safe", as diode or something?
Here is the simple schematic, I am aking about this particular case. Is this safe or no, and, why?
PS: I know that the connecting two power supplise at once is bad, I am asking only about this particular case (Vin left disconnected, only 5V from USB connected)