Bridge Rectifier

bridge rectifier with filter

1. Bridge Rectifier

2. INTRODUCTION A   rectifier  is an electrical device that  converts   alternating current  (AC), which periodically reverses direction, to  direct current  (DC), which flows in only one direction. The process is known as  rectification , since it "straightens" the direction of current . A rectifier is an electrical device that converts alternating current(AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification

3. Half-wave rectification Full-wave rectification Full-wave rectifier using a  center tap  transformer and 2 diodes. Rectifier circuits

4. BRIDGE RECTIFIER with filter (A full-wave rectifier using four diodes)

5. A rectifier diode ( silicon controlled rectifier ) and associated mounting hardware. The heavy threaded stud attaches the device to a  heatsink  to dissipate heat.

6. MODEL : SIMULATION *This shows a AC transformer plus full-wave bridge rectifier. It converts 230 volts AC to 220 volts DC. *The full-wave bridge rectifier plus capacitor combination then converts this to DC. *The resistor represents a typical load.

7. Simulation Results shows how AC voltage is converted to DC Voltage

8. Filters The devices which converts the pulsating DC in to pure DC is called filter. As the name specifies it filters the oscillations in the signal and provides a pure DC at the output. The electronic reactive elements like capacitor and inductors are used to do this work. Filters for Rectifier Circuits

9. Capacitor filter The pulsating Direct Current (DC) produced by the full wave rectifier contains both AC and DC components . We know that the capacitor allows the AC components and blocks the DC components of the current . When the DC current that contains both DC components and AC components reaches the filter, T he DC components experience a high resistance from the capacitor whereas the AC components experience a low resistance from the capacitor.

10. Electric current always prefers to flow through a low resistance path. So the AC components will flow through the capacitor whereas the DC components are blocked by the capacitor. Therefore, they find an alternate path and reach the output load resistor R L . The flow of AC components through the capacitor is nothing but the charging of a capacitor.   Thus, the filter converts the pulsating DC into pure DC

11. The output of the rectifier pulsating in nature, it consists of a desired DC component of voltage and unwanted ripple components. These ripple components are removed by placing filter circuit at the output of the rectifier.

12. The pulsating Direct Current (DC) produced by the full wave rectifier contains both AC and DC components . We know that the capacitor allows the AC components and blocks the DC components of the current. When the DC current that contains both DC components and AC components reaches the filter, the DC components experience a high resistance from the capacitor whereas the AC components experience a low resistance from the capacitor. Electric current always prefers to flow through a low resistance path. So the AC components will flow through the capacitor whereas the DC components are blocked by the capacitor. Therefore , they find an alternate path and reach the output load resistor R L . The flow of AC components through the capacitor is nothing but the charging of a capacitor. Thus , the filter converts the pulsating DC into pure DC

13. When input AC signal is applied across the bridge rectifier, during the positive half cycle diodes D 1  and D 2  are forward biased and allows electric current while the diodes D 3  and D 4 are reverse biased and blocks electric current. On the other hand, during the negative half cycle diodes D 3  and D 4  are forward biased and allows electric current while diodes D 1  and D 2 are reverse biased and blocks electric current. During the positive half cycle, the terminal A becomes positive while the terminal B becomes negative. This causes the diodes D 1  and D 2  forward biased and at the same time, it causes the diodes D 3  and D 4  reverse biased. The smoothing capacitor converts the full-wave rippled output of the rectifier into a more smooth DC output voltage.