# Triangular Symbol in a A circuit

What is the meaning of the triangle above with "5v" written next to it? is that a ground symbol or an input voltage symbol?

• Is this homework? – user253751 Mar 1 '18 at 4:19
• No, it is not a homework. – NegativeTension Mar 1 '18 at 4:27

Here's some hints to what it may be

• It says 5 V, it does not say $V_{in}$
• it is a constant 5 V
• I am new to electronics, but I am guessing the node connected directly to it should be 5v with respect to the bottom ground? – NegativeTension Mar 1 '18 at 4:25
• @NegativeTension Yes, it's a way to say this is connected to your 5V supply – user253751 Mar 1 '18 at 4:31
• I object to your last bullet. You can have ground pointing upwards, even though it could look strange but I've seen it in textbooks and even at work. Also, you can have this type of connection pointing downwards as well. You can see it on amplifier schematics where the power rail of the amplifier has a downwards arrow (e.g. negative supply rail). – KingDuken Mar 1 '18 at 5:52
• @KingDuken I'd prefer some proof, but I've seen.. similar things... so it's not impossible, and that's enough for me to delete that part of my answer. – Harry Svensson Mar 1 '18 at 6:17
• @HarrySvensson I'm not trying to negatively criticize :) just wanted to make sure your answer was less ambiguous. – KingDuken Mar 1 '18 at 15:33

The "triangle" is not a part, it is an arrow pointing to the positive (in this case) power supply connection. A positive supply is required for the NPN transistor to operate.

Generally people use signals that look like this for schematics:

It looks like someone threw in a ground signal and then put a label on it, which is confusing, but they did label it 5V so I'd roll with that.