Hello all
I have meticulously studied hundreds of examples of BJT transistor circuits organised into common emitter, common collector and common base configurations. I find that all these tutorial sites are written way above my pay grade, and when they start showing formulae and discussing how this b current joins with this c current to form e current, my eyes glaze over. Could someone tell this thick-o if the following simple rules are true...
1. If the base is connected to the ground with no resistor, it's a common base circuit.
2. If the collector is connected to the V+ with no resistor, it's a common collector circuit.
3. If the emitter is connected to the ground with no resistor, it's a common emitter circuit.
4. If the out is tapped off the collector it is generally a common emitter circuit (exception being rule 1).
5. If the out is tapped off the emitter it is generally a common emitter circuit.
6. If the input circuit and output circuit share say a collector then it is a common collector circuit.

Take the above circuit. I find rule 6 meaningless in real working circuits since the in and out circuits in the above diagram seem to share both emitter and collector. From rule 2 I recognise this as common collector but I cannot see why they say the collector is common to both in and out. What am I missing.
Thank you.
I have meticulously studied hundreds of examples of BJT transistor circuits organised into common emitter, common collector and common base configurations. I find that all these tutorial sites are written way above my pay grade, and when they start showing formulae and discussing how this b current joins with this c current to form e current, my eyes glaze over. Could someone tell this thick-o if the following simple rules are true...
1. If the base is connected to the ground with no resistor, it's a common base circuit.
2. If the collector is connected to the V+ with no resistor, it's a common collector circuit.
3. If the emitter is connected to the ground with no resistor, it's a common emitter circuit.
4. If the out is tapped off the collector it is generally a common emitter circuit (exception being rule 1).
5. If the out is tapped off the emitter it is generally a common emitter circuit.
6. If the input circuit and output circuit share say a collector then it is a common collector circuit.

Take the above circuit. I find rule 6 meaningless in real working circuits since the in and out circuits in the above diagram seem to share both emitter and collector. From rule 2 I recognise this as common collector but I cannot see why they say the collector is common to both in and out. What am I missing.
Thank you.