I am kind of new to electronics, and I am eager to learn how to work with transistors; especially in realizing logic gates with them. I tried to build a very basic circuit with a transistor as my "switch", turning an LED on and off. However, even if I have no Powersource connected to the collector, there is current indicated by the amp-meter and my LED is turned on (please see screenshots below).
My questions are:
1.) How is my circuit wrong? Why is there 1/4th of the current present even though there is no connection from the +6V to my collector?
2.) When it comes down to transistors I often run accross schematics where the NPN's collector and base are connected to individual plus-power-sources (e.g. +6V), while the emitter is connected to ground (with some load in between). I am wondering how the +x V nodes and the ground are realized in a "real world environment"? Would you use 2 Batteries and connect both -Nodes with ground?
1.) NPN-Setup, no connection to the NPN's collector:
2.) NPN-Setup, NPN's collector powered: