11.5 Rectification Flashcards
What is rectification?
Where Ac current is converted to a Dc current in which the electrons all flow in the same direction.
What is half wave rectification?
This conversion can be partially achieved with a single diode. A diode allows current to pass through it in only one direction. When the current is positive it is allowed to pass through when it is negative it doesn’t. The output is direct current although it is not constant. In half rectification therefore half the power is lost.
What is full wave rectification?
Four diodes in a diode bridge rectifier, all diodes point in the same way.
What happens in the first half cycle of full wave rectification?
The current moves clockwise entering the bridge through diode 1 passing through the load resistor from left to right and exiting through diode 3. During this half cycle diodes 2 and 4 do not conduct any current.
What happens in the next half cycle of full wave rectification?
The current moves anticlockwise entering the bridge through diode 4 moving through the load from left to right again in the same direction as the first half cycle and exiting through diode 2. During this half cycle does 1 and 3 do not conduct any current.
How can the output current of the diode bridge rectifier be made smoother?
By adding a capacitor in parallel with the load resistor. The output is now smoother although it still has a ripple, the greater the capacitance the less the ripple.
