What is the step to manufacture a diode ? just briefly explain would be enough =] thx for the help...

 

Well obviously, you would need a PN (Positive-Negative) junction. This is the basic formation of a diode. Why don't you research diodes a little more via google?

 

Hello,

Take a look at this:
http://jas.eng.buffalo.edu/education/fab/pn/diodeframe.html

Greetings,
Bertus

 

A heated cathode and a plate in a vacuum works. Here's how it's done - http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm

 

Well obviously, you would need a PN (Positive-Negative) junction. This is the basic formation of a diode. Why don't you research diodes a little more via google?

Not necessarily, read up on Shottky Diodes, which resembles the classic cat's whisker diode of yore. BTW, Cat's whisker diodes were a form of homemade diodes used in crystal sets back when radio was new.

The old tube rectifiers were another good way, as beenthere mentioned. Correct me if I'm wrong, but they were part of the old tube radio's power supplies, and could handle some decent wattage too.

 

Not necessarily, read up on Shottky Diodes, which resembles the classic cat's whisker diode of yore. BTW, Cat's whisker diodes were a form of homemade diodes used in crystal sets back when radio was new.

Forgot about Shottky diodes... Yes, gernamium diodes have what we call a "cat's whisker" inside and it is completely visible. I've seen this homeade crystal radio set with a homemade diode, and you can see the cats whisker. Pretty neat!

 

Actually you're talking simple wire. You'd love to see my job, where we use automated machines (robots with vision) to lay 0.001" wire on microelectronics (individual chip die on ceramic boards). A short thin wire can handle a lot of current.

Cat's whisker, as I understand it, actually operated off the Shottky Diode principle, before it was understood as such.

There were also Selinium Rectifiers, used for early automotive, where they stacked plates of dissimilar metals to make rectifiers that were pretty inefficient.

Rectifiers actually have a long history, we are looking at over a century of R&D, and are spoiled by the current crop of devices.

 

Hello Bill,

Those selenuim rectifiers where not nice at all.
When the current was to high and they burned you had a terrible smell of rotten eggs.

Greetings,
Bertus

 

Rotten eggs! - more like a dead mouse.

Additional diodes may be made using a point contact to an oxide film. That was the rectifier in a foxhole radio in WWII, using the blued film on a razor blade. A tungsten needle just contacting a pool of nitric acid will work, poorly. White hot copper oxide got investigated back in the 1920's.