...afraid to ask!

[Chris K]

I read that but I still don't understand how or why you would use it in a circuit. What does it do for you? Are you forced to use it by the nature of the circuit? I'll stick with tubes...no transistors...the gaps in my understanding with those devices is vast.

[Yamamaya42]

Originally Posted by Chris K

I read that but I still don't understand how or why you would use it in a circuit. What does it do for you? Are you forced to use it by the nature of the circuit? I'll stick with tubes...no transistors...the gaps in my understanding with those devices is vast.

All of this, well a lot of it was gone over in the vocational electronics classes I went through in HS, most of which has been forgotten over the years of course!
But a lot of what was tough did stick, like the VERY NSFW mnemonic for the resistor color code!

[Chris K]

Originally Posted by Yamamaya42

All of this, well a lot of it was gone over in the vocational electronics classes I went through in HS, most of which has been forgotten over the years of course!
But a lot of what was tough did stick, like the VERY NSFW mnemonic for the resistor color code!

That's another intractable hurdle for me in electronics...I'm color blind so I have to ask my wife to give me the color bands! I'll stick to B&W TVs for now!

[old_coot88]

Think of a tube as a valve (the British term for it), because that's what it does, it valves or regulates electron flow. In a triode, the grid is the control element. Negative voltage on the grid (with respect to cathode) is the bias voltage. It
controls how much current flows from cathode to anode(plate). More negative equals less current, less negative equals more current. So you want the bias point to be fixed midway between minimum and maximum plate current swings, i.e., the idling current. When a small signal is applied to the grid, it "valves" a corresponding LARGE flow of plate current. The bias point being fixed midway gives the best linearity to the amplified signal (which appears across the plate load, which can be a resistor, an output transformer, old-school headphones, etc.).