- #1
It is about common emitter configurations
- Thread starter saranga
- Start date
Click For Summary
The discussion revolves around the classification of a transistor configuration, specifically whether it is a common emitter or common collector setup. Participants clarify that in a common emitter configuration, the emitter is grounded and serves as a reference point for both input and output, with the input typically applied to the base and the output taken from the collector. There is some confusion regarding the input and output connections, which are not clearly shown in the original diagram. The consensus is that if the emitter is grounded and the base is receiving a bias voltage, it supports the common emitter classification. Overall, the importance of identifying the input and output in circuit diagrams is emphasized for proper classification.
- #2
Tom.G
Science Advisor
Gold Member
- 5,661
- 4,506
But you didn't show where the input and output are.
An input signal (if you want gain), changes the applied voltage between Base and Emitter.
The emitter voltage won't change in this circuit because it's grounded. Therefore the input must be the Base.
The only way left to get an output is the Collector and typically the signal is the collector voltage referenced to Ground.
Since the Emitter is used as the reference for both input and output, It is called a common-Emitter configuration.
If you have a circuit with the Base grounded, the signal input is to the Emitter, and output is from the Collector, you have a common-Base configuration.
An input signal (if you want gain), changes the applied voltage between Base and Emitter.
The emitter voltage won't change in this circuit because it's grounded. Therefore the input must be the Base.
The only way left to get an output is the Collector and typically the signal is the collector voltage referenced to Ground.
Since the Emitter is used as the reference for both input and output, It is called a common-Emitter configuration.
If you have a circuit with the Base grounded, the signal input is to the Emitter, and output is from the Collector, you have a common-Base configuration.
- #3
Electron Spin
- 52
- 28
Tom.G said:
Your right Tom, I would guess Rb is a bias Resistor, The Emitter is tied to ground and the Collector to Vcc..Now let's assume the input is tied to the Base and the output is picked off the Rc by convention..If we do, then I would guess it is a CE...
To the OP.. The element that has no input or output and typically tied to grd is the "common", hence, Common Emitter, Base, or Collector..
Again, since the emitter is grounded and the collector has a Rc or load resistor and guessing the base is being fed a bias voltage from the collector, the only element with no in/output would assumably be the emitter..Once again, with a little supposition, this could be a common emitter configuration since the emitter is common to the input and output, and is grounded.
Once again, like Tom said..without the in/output being showed we both are kinda' guessing here saranga...
Sorry for the redundancies in advance...
Tom.G said:
^^^^^^^^^
This definition, right here.
- #4
saranga
- 13
- 0
thanks it should be my faultTom.G said:
- #5
saranga
- 13
- 0
thank you,no your discription is effective.Electron Spin said:Your right Tom, I would guess Rb is a bias Resistor, The Emitter is tied to ground and the Collector to Vcc..Now let's assume the input is tied to the Base and the output is picked off the Rc by convention..If we do, then I would guess it is a CE...
To the OP.. The element that has no input or output and typically tied to grd is the "common", hence, Common Emitter, Base, or Collector..
Again, since the emitter is grounded and the collector has a Rc or load resistor and guessing the base is being fed a bias voltage from the collector, the only element with no in/output would assumably be the emitter..Once again, with a little supposition, this could be a common emitter configuration since the emitter is common to the input and output, and is grounded.
Once again, like Tom said..without the in/output being showed we both are kinda' guessing here saranga...
Sorry for the redundancies in advance...
^^^^^^^^^
This definition, right here.
- #6
lychette
- 413
- 73
Electron Spin said:Your right Tom, I would guess Rb is a bias Resistor, The Emitter is tied to ground and the Collector to Vcc..Now let's assume the input is tied to the Base and the output is picked off the Rc by convention..If we do, then I would guess it is a CE...
To the OP.. The element that has no input or output and typically tied to grd is the "common", hence, Common Emitter, Base, or Collector..
Again, since the emitter is grounded and the collector has a Rc or load resistor and guessing the base is being fed a bias voltage from the collector, the only element with no in/output would assumably be the emitter..Once again, with a little supposition, this could be a common emitter configuration since the emitter is common to the input and output, and is grounded.
Once again, like Tom said..without the in/output being showed we both are kinda' guessing here saranga...
Sorry for the redundancies in advance...
^^^^^^^^^
This definition, right here.
Completely agree...common emitter
I grabbed an under cabinet LED light today at a big box store. Nothing special. 18 inches in length and made to plug several lights together. Here is a pic of the power cord:
The drawing on the box led me to believe that it would accept a standard IEC cord which surprised me. But it's a variation of it. I didn't try it, but I would assume you could plug a standard IEC cord into this and have a double male cord AKA suicide cord. And to boot, it's likely going to reverse the hot and...