Brian Hoskins
New Member
The main application for a conventional diode is not it's forward voltage drop but the fact that current is only able to flow in one direction through them (apart from a small leakage current when reverse biased). As Hero said, the forward voltage drop is dependant on current, and to a smaller amount other factors such as temperature. As an example, if you read the datasheet for a general purpose diode like the 1n4001 you'll see a graph which plots forward voltage against current. The device is rated up to 1Amp, and from 0 - 1Amp the forward voltage varies by 0.4V - this is why they're not very good voltage droppers, unless the circuit current is known and remains fairly constant.
Brian
Brian