earlybird
Well-known member
You mean a positron then?
Wiring up a shunt
- Thread starter boatmike
- Start date
You mean a positron then?
nigelmercier
RIP
- Joined
- 20 Jun 2007
- Messages
- 16,234
- Location
- Live in Kent, boat in Canary Islands
Indeed, anti-electron or positron was what I was trying to avoid when describing electron holes. Not the same thing at all, one is a real exotic particle, the other is an invention to describe current flow.
Last edited:
VicS
Well-known member
oh no. That's something real, a particle of antimatter.
An electron hole is the position where an electron could be.
pvb
Well-known member
Ah, so when these electrons get "tired and shagged-out by passing through a load", as Nigel so clearly put it, they crawl into a hole for a rest, do they?
VicS
Well-known member
I dont know if they really get tired and shagged out but they go into their holes when you turn the switch off.
boatmike
Well-known member
Gawd fellers, I have just got home and decided to just check if anything else had been added..... Talk about Fred Drift... Its SUNDAY!!! Don't you guys ever go out??
VicS
Well-known member
We keep the thread alive and near the top of the first page and that all the thanks we get!
William_H
Well-known member
Electrons and holes
Continuing the thread drift madness......No they don't all go into their holes when the switch is turned off. The electrons left in excess and holes left wanting is called capacitance.
Consider that if you had a circuit of a battery a switch and a lamp connected by wire to operate correctly. Now consider that the wire has been cut. When the switch is closed do the electrons have to shuffle down the wire and pull down the wire on the other side only to find there is a gap in the wiring? The answer is yes. The electrons will pile up on one side and the holes will appear on the other side until the electrons and holes are finally convinced that current is not going to flow. The size of the pile up depends on the proximity of the 2 wire ends, the area of the ends in proximity and what material is between the ends. So if we take this to extremes of square meters of ends just microns apart we have a capacitor. Amps can flow in, slowly diminishing until the voltage across the gap rises and no more current flows. If we disconnect the battery and lamp we find that this tension across the gap of excess electrons and holes remains until a circuit can be made to allow them to get back to normal relaxed. If we reverse the battery and connect again then a large current will flow to dissipate this tension then rebuild it in the other direction. Indeed this capacitor can look like a battery albeit of small capacity and a voltage which falls rapidly. Capacitors using this effect are an essential building block of any electronics.
Hows that for being pedantic and for thread drift. olewill
Hi Vic
Continuing the thread drift madness......No they don't all go into their holes when the switch is turned off. The electrons left in excess and holes left wanting is called capacitance.
Consider that if you had a circuit of a battery a switch and a lamp connected by wire to operate correctly. Now consider that the wire has been cut. When the switch is closed do the electrons have to shuffle down the wire and pull down the wire on the other side only to find there is a gap in the wiring? The answer is yes. The electrons will pile up on one side and the holes will appear on the other side until the electrons and holes are finally convinced that current is not going to flow. The size of the pile up depends on the proximity of the 2 wire ends, the area of the ends in proximity and what material is between the ends. So if we take this to extremes of square meters of ends just microns apart we have a capacitor. Amps can flow in, slowly diminishing until the voltage across the gap rises and no more current flows. If we disconnect the battery and lamp we find that this tension across the gap of excess electrons and holes remains until a circuit can be made to allow them to get back to normal relaxed. If we reverse the battery and connect again then a large current will flow to dissipate this tension then rebuild it in the other direction. Indeed this capacitor can look like a battery albeit of small capacity and a voltage which falls rapidly. Capacitors using this effect are an essential building block of any electronics.
Hows that for being pedantic and for thread drift. olewill
cimo
Member
Its funny the things that stay with you.
One of my first engineering texts put it very well with a quote from Aristotle -
"it's the mark of an instructed mind to rest satisfied with that degree of precision which a subject allows, and not to seek exactness where only an approximation of the truth is possible".
I'm paraphrasing, but he was right then and he's still right today.
Very Zen I thought.
It is/was indeed Sunday, and I have been out all evening & it is possible to get graduated analog ammeters.
I'd be very disappointed if I were to have the last word on this matter.
One of my first engineering texts put it very well with a quote from Aristotle -
"it's the mark of an instructed mind to rest satisfied with that degree of precision which a subject allows, and not to seek exactness where only an approximation of the truth is possible".
I'm paraphrasing, but he was right then and he's still right today.
Very Zen I thought.
It is/was indeed Sunday, and I have been out all evening & it is possible to get graduated analog ammeters.
I'd be very disappointed if I were to have the last word on this matter.
boatmike
Well-known member
"it's the mark of an instructed mind to rest satisfied with that degree of precision which a subject allows, and not to seek exactness where only an approximation of the truth is possible".
That's approximately right.........
That's approximately right.........
nigelmercier
RIP
- Joined
- 20 Jun 2007
- Messages
- 16,234
- Location
- Live in Kent, boat in Canary Islands