I know this is probably beating a dead horse, but transistors are one of those simple things that I always confuse myself with.
I have a group of LEDs that are normally in an off state, and are turned on via an Arduino looking as switches and such. The initial design I have is using 2N3906s to switch on the positive side of the LED, such as this:
The circuit works, but after looking at it, it seems like if the LEDs are normally off, having the Arduino constantly putting out a HIGH signal to keep the 2N3906 off seems like a waste of power, and I don't like the idea of having too much constant current through the Arduino board. Because of this, I'd like to replace the PNP with NPN. Would the following work? The emitter and collector are swapped from where they were as PNP and the signal on the base is inverted.
I just wanted opinions before I break out the soldering iron. Because of physical limitations, the LEDs need to stay common ground.
I have a group of LEDs that are normally in an off state, and are turned on via an Arduino looking as switches and such. The initial design I have is using 2N3906s to switch on the positive side of the LED, such as this:
The circuit works, but after looking at it, it seems like if the LEDs are normally off, having the Arduino constantly putting out a HIGH signal to keep the 2N3906 off seems like a waste of power, and I don't like the idea of having too much constant current through the Arduino board. Because of this, I'd like to replace the PNP with NPN. Would the following work? The emitter and collector are swapped from where they were as PNP and the signal on the base is inverted.
I just wanted opinions before I break out the soldering iron. Because of physical limitations, the LEDs need to stay common ground.