Full-Wave Bridge  Rectifier

Full-Wave Bridge Rectifier

Project Type: Presentation (pptx)

Downloads: 0 - 10 Saturday 18th March 2017 Report

Full-Wave Bridge Rectifier - Overview

------------ PAGE 1 ------------ FULL- WAVE BRIDGE RECTIFIER DETAILS and REAL- LIFE APPLICATIONS ------------ PAGE 2 ------------ WHAT IS FULL- WAVE BRIDGE RECTIFIER ? RECTIFIER : A RECTIFIER IS AN ELECTRONIC CIRCUIT THAT CONVERTS AC VOLTAGE TO DC VOLTAGE. FULL WAVE BRIDGE RECTIFIER : BRIDGE RECTIFIER IS A FULL WAVE RECTIFIER CIRCUIT USING THE COMBINATION OF FOUR DIODES TO FORM A BRIDGE . IT HAS THE ADVANTAGES THAT IT CONVERTS BOTH THE HALF CYCLE OF AC INPUT TO DC OUTPUT. ------------ PAGE 3 ------------ CIRCUIT DIAGRAM ------------ PAGE 4 ------------ ABOUT DIAGRAM HOW TO IT WORKS ? ƒæ when the input connected to the left corner of the diamond is positive, and the input connected to the right corner is negative, current flows from the upper supply terminal to the right along the red ( positive) path to the output, and returns to the lower supply terminal via the blue ( negative) path. ƒæ When the input connected to the left corner is negative, and the input connected to the right corner is positive, current flows from the lower supply terminal to the right along the red ( positive) path to the output, and returns to the upper supply terminal via the blue ( negative) path ------------ PAGE 5 ------------ OUTPUT FREQUENCY ƒá According to the figure, when D1 and D3 are forward biased, they conduct but D2 and D4 and on D1 and D3 are reverse biased in both cases load current in the same direction. ------------ PAGE 6 ------------ PEAK INVERSE VOLTAGE( PIV) • The peak inverse voltage ( PIV) of each diode is equal to the maximum secondary voltage of transformer . Suppose during positive half cycle of input a. c. , end P of secondary is positive and end Q negative . Under such condition diodes D1 and D3 are forward biased while diodes D2 and D4 are reverse biased. Since the diodes are considered ideal, diodes D1 and D3 can be replaced by wires as shown in Fig( 1). This circuit is the same as shown in Fig( 2). In Fig( 2), it is clear that two reverse biased diodes D2 and D4 and the secondary of transformer are in parallel . Hence PIV of each diode is equal to the maximum voltage ( Vm) across the secondary. Similarly, during the next half cycle, D2 and D4 are forward biased while D1 and D3 will be reverse biased then the reverse voltage across D1 and D3 is equal to Vm. ------------ PAGE 7 ------------ Vm. ------------ PAGE 8 ------------ APPLICATION • The primary application of rectifiers is to derive DC power from an AC supply ( AC to DC converter). • Rectifiers are also used for detection of amplitude modulated radio signals. • Rectifiers supply polarized voltage for welding. • Vibrating rectifier ------------ PAGE 9 ------------ RECTIFICATION TECHNOLOGIES • Synchronous rectifier • Vibrating rectifier • Motor- generator set • Electrolytic ------------ PAGE 10 ------------ ADVANTAGES: • The rectification efficiency of full- wave rectifier is double of that of a half- wave rectifier. • The ripple voltage is low and of higher frequency in case of full- wave rectifier so simple filtering circuit is required. • Higher output voltage, higher output power and higher Transformer Utilization Factor ( TUF) in case of a full- wave rectifier. ------------ PAGE 11 ------------ DISADVANTAGES: • The main disadvantage of a bridge rectifier is that it needs four diodes. • Two of which conduct in alternate half- cycles of a. c. input two diodes that conduct are in series, therefore, voltage drop in the internal resistance of the rectifying unit. • Objectionable when secondary voltage is small. ------------ PAGE 12 ------------ THANK YOU
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