Basic Diodes/Van de Graaff generator

[Steven Ellet]

What is the name of the most basic diode?
I know that there are quite a few types of diodes, but all I want is one that will force electricity to flow in one direction and do nothing else.
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On an unrelated note, how would a Van de Graaff generator that makes a negative charge, vary from one that makes a positive charge, and how would I make one that does positive?

 

[MrSparkle]

The basic diode is just a PN-junction diode.

They won't do it at voltages created by a Van de Graaff generator. diodes have a 'reverse breakdown' voltage, at which they will freely conduct current in the opposite direction. In fact, diodes are used as protection against static electricity by having them short to ground when faced with voltages higher than the circuit is supposed to see (ie greater than 15 volts).

 

[Steven Ellet]

I thank you for answering one of my questions, however I was not implying that the two would work together, only that I wished for two answers but did not wish to make two post.

 

[Baluncore]

The Van de Graaff generator has two rollers for the belt. One is metal, the other is insulated.
I believe it is the position of those rollers, and the belt material that determines polarity.
If you swap the rollers you should change the polarity.

 

[alphy]

The most basic diode is called a P-N junction diode, which consists of a semiconductor material with a p-type and n-type layer. It allows current to flow in only one direction, from the p-type to the n-type layer.

A Van de Graaff generator that produces a negative charge would have the polarity of its components reversed compared to one that produces a positive charge. In order to make a positive Van de Graaff generator, you would need to switch the polarity of the components, such as the belt and the comb, so that they attract positive charges instead of negative ones. Additionally, the placement of the belt and comb may also need to be adjusted to ensure the desired charge is produced.