How does a diode clamp work?

Question

I need to know some details, also if anyone knows of a great electronics website about circuit theory that would be great. Thanks

Answer 1

A diode normally conducts in one direction , forward bias (Anode = positive to negative = Cathodee) . How ever a clamp relies on the reverse breakdown voltage. Basically connect a reverse biased (Cathod connected to the positive, Anode connected to the negative) diode across the voltage to be clamped.

When the voltage rises above the reverse break down voltage the diode will conduct.

Zener diodes used as voltage regulators rely on reverse breakdown voltage in order to provide a constant voltage

Answer 2

1

Answer 3

Here's an application with a relay. When you turn off the relay, the current in the coil can't instantaneously stop. It sparks across the switch and sends a voltage spike back to the supply voltage. To prevent this, attach a reverse biased diode in parallel with the coil. Now, when you switch the relay off, the current in the coil flows through the diode while the coil dischages. The voltage on the supply side connection of the coil doesn't go higher than the forward voltage drop of the diode.