Simulation of transistor switch circuit

Hello, I'm new to electronics and I'm reading a book currently to learn more about the topic. I'm currently on a section where I'm building circuits where I'm using a transistor as a switch. I decided to experiment with the circuit they gave me and put it in a simulation software called Proteus. Here it is. There was one thing I was confused on. In the book it told me I can calculate the current across the LED by taking 6V - 1.8 (voltage drop across the LED) and dividing it by the 330Ohm resistor. When they did this they got 12.7mA. However according to the simulation, if you look at the ammeter it reads 10.9mA. Why is this? I also went to calculate the Vce (voltage across the collector and emitter of the transistor) using the KVL method. I calculated the voltage from the source - the voltage drop across the resistor (330*0.0127) and the voltage drop across the LED and set it equal to Vce. This gave me Vce = 6 - (330*0.0127) - 1.8 which equals 9mV. This seems very low to me but doesn't this make sense because if the transistor is in saturation the voltage across the collector and emitter should be really close to 0 right? Lastly, when I took a voltmeter across the collector and emitter in the simulation I got 0.58V. Can somebody tell me if either me or the simulation is screwing up here. I also made sure to set the voltage drop of my LED to 1.8V in the simulation, so that's not the issue. Please help, this is really bothering me.   Attachments upload_2018-3-21_11-1-29.png 32.3 KB · Views: 998

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