Voltage Drop

No, a voltage won't break if you drop it.., but voltage drops are important in electronics!

A voltage drop is how the voltage at a point in a circuit decreases because of the "hidden resistance' we found out about in Project Secret resistance in resistance section.

This Project will show a voltage drop because of a diode. After you complete the wiring, put the power ON.

You'll see the Meter pointer move. Now press the Key, what happens to the Meter?

Can you guess why this happens? (Examine the schematic carefully).

When you press the Key, the Meter gives a higher reading. This is because the Key "shorts out" the Diode. The Diode has a voltage drop which slightly reduces the amount of electricity that reaches the Meter.

Releasing the Key puts the Diode back into the circuit, causing the Meter indication to drop. Remember that electricity always takes the easiest path in a circuit. When you press the Key, the electricity has an easier path to follow than going through the Diode, The electricity goes through the Key instead of the Diode.

In this Project the Diode reduces the voltage reaching the Meter from the 4.5 volts supplied by the Batteries to 3.9 volts. We say the Diode has a voltage drop of 0.6 volts. Resistors also have a voltage drop across them too, We often use diodes (or resistors) and their voltage drops to supply a desired voltage to various components in circuits.