Skip to main content
Electrical Engineering

Return to Question

Bumped by Community user
don't mark edits in the text since we can see the edit history
Source Link
Null ♦
Null ♦
  • 7.7k
  • 17
  • 37
  • 48

(edits marked with bold text. I misasked this) I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to and the emitter outputs the correct current, but I have a question with the Base current. Suppose we have a 5V5 V supply both at the C and B. There is also a resistor at the B and another at C. Using a simulator, it draws way less current than the calculation I did with Ohm's law. I also found out that the resistor at C plays a role here.I also found out that the resistor at C plays a role here. My question is how does the resistor at C affect the current at B.?

Two resistors at B and C. Ampermeters are marked with arrows.

(edits marked with bold text. I misasked this) I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to and the emitter outputs the correct current, but I have a question with the Base current. Suppose we have a 5V supply both at the C and B. There is also a resistor at the B and another at C. Using a simulator, it draws way less current than the calculation I did with Ohm's law. I also found out that the resistor at C plays a role here. My question is how does the resistor at C affect the current at B.Two resistors at B and C. Ampermeters are marked with arrows.

I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to and the emitter outputs the correct current, but I have a question with the Base current. Suppose we have a 5 V supply both at the C and B. There is also a resistor at the B and another at C. Using a simulator, it draws way less current than the calculation I did with Ohm's law. I also found out that the resistor at C plays a role here. My question is how does the resistor at C affect the current at B?

Two resistors at B and C. Ampermeters are marked with arrows.

I fixed some vague parts, that don't make any sense. I also drew another schematic.
Source Link
Vargánya Művek
Vargánya Művek
  • 99
  • 4

(edits marked with bold text. I misasked this) I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to (marked with the ampermeter) and the emitter outputs the correct current, but I have a problemquestion with the Base current (marked with an arrow). Suppose we have a 5V supply both at the C and B. There is also a 470Ω resistor at the B and another at C. Using Ohm's law, I calculated that the Base current would be 10,6 mA, but using a simulator, it draws way less current than thatthe calculation I did with Ohm's law. I also found out that the resistor at C plays a role here. I would like some help on why does that happen. Sorry, if thisMy question is vaguehow does the resistor at C affect the current at B.I drew a schematic as well. This is a VERY crude amplifier, I know.Two resistors at B and C. Ampermeters are marked with arrows.

I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to (marked with the ampermeter) and the emitter outputs the correct current, but I have a problem with the Base current (marked with an arrow). Suppose we have a 5V supply both at the C and B. There is also a 470Ω resistor at the B. Using Ohm's law, I calculated that the Base current would be 10,6 mA, but using a simulator, it draws way less current than that. I would like some help on why does that happen. Sorry, if this question is vague.I drew a schematic as well. This is a VERY crude amplifier, I know.

(edits marked with bold text. I misasked this) I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to and the emitter outputs the correct current, but I have a question with the Base current. Suppose we have a 5V supply both at the C and B. There is also a resistor at the B and another at C. Using a simulator, it draws way less current than the calculation I did with Ohm's law. I also found out that the resistor at C plays a role here. My question is how does the resistor at C affect the current at B.Two resistors at B and C. Ampermeters are marked with arrows.

Source Link
Vargánya Művek
Vargánya Művek
  • 99
  • 4

NPN transistor base doesn't drain as much current as I calculated

I am very new to transistors unfortunately, so sorry if I don't know every formula already. The thing is, I would like to use a bipolar NPN transistor as an amplifier. It has a current gain of 200. The Collector does drain the current it is supposed to (marked with the ampermeter) and the emitter outputs the correct current, but I have a problem with the Base current (marked with an arrow). Suppose we have a 5V supply both at the C and B. There is also a 470Ω resistor at the B. Using Ohm's law, I calculated that the Base current would be 10,6 mA, but using a simulator, it draws way less current than that. I would like some help on why does that happen. Sorry, if this question is vague.I drew a schematic as well. This is a VERY crude amplifier, I know.