Hello everybody! I'm posting this because I'm new to electronics in general. I've read tutorials on 'sparkfun.com' that have introduced me to the concept of using a transistor as a switch, but I'd like to ask a few questions(most likely noobly ones) about how I can really use one in the future.
What I'd like to know is how I can determine which specific transistor I can use, where the base receives a HIGH signal from an I/O pin my arduino mega2560, to allow voltage to travel from the collector to the emitter.
Does the voltage that I'd like to pass through the collector and emitter need to be specific or can there be a range(possible between 5VDC and 24VDC)?
I have an unknown voltage/current (finding out very soon after I measure the current/voltage in the next couple days while I'm at work) from two different pins that need to connect to ground to turn on specific features on a mass flow controller. IF it's a 5V pin that I want to switch on or off using a transitor, would the BC337 or BC338 NPN transister work for this? I've looked at the data sheets and I THINK this is what I could use but like I said, I am very new to this field and do not have enough experience to rely on my own knowledge.. for now..
If anybody has a moment to assist me in my learning process, it would be much appreciated!