Ferg Deluxe
Platinum Supporting Member
- Messages
- 2,568
Over the last few weeks, I've been doing a lot of reading about tubes -- specifically how they work -- and trying to figure out exactly what's going on inside a tube guitar amp. This is just for my own edification and curiosity, not because I'm troubleshooting a specific problem. Anyhow, during my internet travels I have come across many references describing the origins of tubes and how they work. However, two of these in particular made a reference to a concept that seems "backwards" to me.
Here are the direct quotes from both references (I'm going to try to give as much context as I can without making the quotes too long):
1. Suppose now an electrode in the form of a plate is introduced in the bulb and a potential positive with respect to the filament is applied to it. The negative electrons will flow to the plate. Instead of thinking of a flow of electrons from the filament to the plate, we generally think of a flow of current from the plate to the filament; that is, from the positive to the negatively charged body.
2. The electrons move from the cathode (K), the negative electrode, to the anode or plate (P), the positive electrode. Conventional current is in the opposite direction.
Both of these references seem to be saying that, inside of a tube, electrons flow from the cathode (negatively charged area) to the anode (positively charged area), but this movement is different from conventional thought about current.
If electricity is the movement of electrons (which it is), and electrons are negatively charged (which they are) then movement would always be from an area of high negative charge to an area of lower negative charge. How could it go the other way? What am I missing here? These don't seem like misprints, and it struck me when I saw two different pages essentially saying the same thing.
Thanks!!
Ferg

PS: here are links to the pages where I got these quotes.
1. http://earlyradiohistory.us/1920vacu.htm
2. http://www.du.edu/~etuttle/electron/elect27.htm#Theory
Here are the direct quotes from both references (I'm going to try to give as much context as I can without making the quotes too long):
1. Suppose now an electrode in the form of a plate is introduced in the bulb and a potential positive with respect to the filament is applied to it. The negative electrons will flow to the plate. Instead of thinking of a flow of electrons from the filament to the plate, we generally think of a flow of current from the plate to the filament; that is, from the positive to the negatively charged body.
2. The electrons move from the cathode (K), the negative electrode, to the anode or plate (P), the positive electrode. Conventional current is in the opposite direction.
Both of these references seem to be saying that, inside of a tube, electrons flow from the cathode (negatively charged area) to the anode (positively charged area), but this movement is different from conventional thought about current.
If electricity is the movement of electrons (which it is), and electrons are negatively charged (which they are) then movement would always be from an area of high negative charge to an area of lower negative charge. How could it go the other way? What am I missing here? These don't seem like misprints, and it struck me when I saw two different pages essentially saying the same thing.
Thanks!!
Ferg
PS: here are links to the pages where I got these quotes.
1. http://earlyradiohistory.us/1920vacu.htm
2. http://www.du.edu/~etuttle/electron/elect27.htm#Theory