Electrics or Electronics

[Landlubber]

Hi all,

I was wondering about this the other night and could not convince myself that I was correct.

Electrics take the power to the electronics, such as 12VDC wiring supply to a depth sounder.

Now we get deeper.....so to speak...we all know that current flows from the +ve to the -ve right, well wrong of course, electron flow is from -ve to +ve as any electronics tech will tell you.

My problems is this. When does it become important in designing electronics to design that the flow in fact is from -ve to +ve. Conventional thinking has us working with current flows, using blocking diodes (silicon rectifiers etc) using the +ve line for all wiring installations. There must be a certain point in design where the real flow becomes important, and has to be obeyed.

I am obviously not an electronic tech (or I would not be asking stupid questions would I) but I do understand electrics pretty well.

I cannot see for the life of me just where this point is.

[TerryKing]

Originally Posted by Landlubber

..snip..When does it become important in designing electronics to design that the flow in fact is from -ve to +ve.

Landlubber, it's good that you take the time to think this through. That's more important than the 'conventions'.

Simple Answer: Don't worry about it. Just keep the "Labelled Polarity" right, like Battery Plus and Minus, Plus and Minus on power connections to gear, etc.

WHEN you need to really keep Electron Flow straight is only when you are actually working with the physics of the materials, like in designing diodes and transistors, designing batteries, and possibly when considering the Galvanic Series relative to corrosion issues. But for any typical boat wiring, Plus and Minus is all you need care about.

If you are wiring up your own chips, the circuit examples will show Vcc connected to a Plus supply, and Vee to Minus /Ground. Don't worry about it.

The Diode Symbol has the arrow pointing for 'conventional' current flow: from Plus towards Minus. When we needed to think or teach about Electron Flow we'd say 'Um, the Electrons flow out of the little megaphone in the Diode Symbol'...

Have fun Doing it...

[Landlubber]

Terry,

I am currently boatbuilding in China too, at Ningbo.

Funny place China, full of Chinese.

[Poida]

This depends of course which came first, the chicken or the egg.

Did they in fact call the positive the positive and the negative the negative before they realized that they had them labelled back to front.

So electrons do flow from negative to positive but the negative has been called positive and the positive negative.

My head hurts.

Poida

[TerryKing]

Originally Posted by Landlubber

I am currently boatbuilding in China too, at Ningbo.

Ningbo, that'd be across the mouth of the Yangtze, South of Shanghai?? Are you close to where two rivers join?? What are you doing with boats??

[Landlubber]

Building the bastards.
We make from 34 to 60 foot, trawlers style, both traditional and modern. All good fun.