JohnnyLemonhead wrote:I went to an accredited technological college of technology, O.K.?
Copied and pasted from Wikipedia:
"The most common function of a diode is to allow an electric current to pass in one direction (called the forward biased condition) and to block the current in the opposite direction (the reverse biased condition). Thus, the diode can be thought of as an electronic version of a check valve."
A couple of real-life problems with this.
A reverse-biased diode WILL permit what is known as "leakage current" to flow through it. Yes, this current is hugely less that the normal forward-biased situation, but it isn't zero. And, of course, it is in a direction opposite to forward-biased current.
Furthermore, there is a "break-down" voltage for any given diode. Once you impose a voltage higher than it in a reverse-biased condition, basically it doesn't act like a diode anymore. Either it will burn out or it will pass some current substantially larger than its reverse-biased current.
--- to avoid boredom, stop reading here
--- if you are already bored, "Oh well..."
Stupid anecdote: my father-out-law used to work on the beam line at Los Alamos National Laboratory, primarily on the electrical power section.
You might not think of it, but typical "diesel" trains really are electrical: the diesel engine runs at essentially its optimum RPM and runs an alternator whose current goes through a bridge rectifier made up of diodes which then runs the whopping big electrical motors that drive the train.
The diodes involved with those motors, of course, are not small. They are not the teensy little diodes you may have built circuits with if you are a DIY'er or are even tinier within an integrated circuit.
Noper, these deal with excess of 1000 amperes of current per motor at full power & usually two motors are running at a time.
So, basically we are talking about incredibly heavy-duty gear.
My father-out-law made himself rather unpopular with the facility's fire chief: not because he used these sorts of diodes, but because he kept burning them out.
Smoke, fire, noise, no fun at all. Still, I think that my ex's-dad got a blast out of both making that stuff work and what happened when it didn't work.