The document describes constructing a full wave bridge rectifier to rectify alternating current (AC) into direct current (DC). [1] It explains the aims are to understand rectification, explain center tapped full wave rectification, and explain bridge full wave rectification. [2] A full wave bridge rectifier uses four diodes arranged in a bridge configuration to allow current to flow through the load in only one direction during both half-cycles of the AC input. [3] The rectified output is filtered by capacitors to produce a smoothed DC voltage that can power devices.
The document describes constructing a full wave bridge rectifier to rectify alternating current (AC) into direct current (DC). [1] It explains the aims are to understand rectification, explain center tapped full wave rectification, and explain bridge full wave rectification. [2] A full wave bridge rectifier uses four diodes arranged in a bridge configuration to allow current to flow through the load in only one direction during both half-cycles of the AC input. [3] The rectified output is filtered by capacitors to produce a smoothed DC voltage that can power devices.
The document describes constructing a full wave bridge rectifier to rectify alternating current (AC) into direct current (DC). [1] It explains the aims are to understand rectification, explain center tapped full wave rectification, and explain bridge full wave rectification. [2] A full wave bridge rectifier uses four diodes arranged in a bridge configuration to allow current to flow through the load in only one direction during both half-cycles of the AC input. [3] The rectified output is filtered by capacitors to produce a smoothed DC voltage that can power devices.
The document describes constructing a full wave bridge rectifier to rectify alternating current (AC) into direct current (DC). [1] It explains the aims are to understand rectification, explain center tapped full wave rectification, and explain bridge full wave rectification. [2] A full wave bridge rectifier uses four diodes arranged in a bridge configuration to allow current to flow through the load in only one direction during both half-cycles of the AC input. [3] The rectified output is filtered by capacitors to produce a smoothed DC voltage that can power devices.
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AIM
To construct a Full Wave Bridge rectifier and show
that the (AC) alternating current is rectified into a direct current (DC).
The aim is to:
1. Understand Rectification. 2. Explain center tapped full wave rectification. 3. Explain Bridge Full Wave Rectification. 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. Rectification produces a type of DC that encompasses active voltages and currents, which are then adjusted into a type of constant voltage DC, although this varies depending on the current's end-use. The current is allowed to flow uninterrupted in one direction, and no current is allowed to flow in the opposite direction.
Physically, rectifiers take a number of forms, including
vaccum tube diodes, mercury-arc valves, copper and selenium oxide rectifiers, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
Rectifier circuits may be single-phase or multi-phase. Most
low power rectifiers for domestic equipment are single-phase, but three-phase rectification is very important for industrial applications and for the transmission of energy as DC. In half wave rectification, either the positive or negative half of the AC wave is passed, while the other half is blocked. Because only one half of the input waveform reaches the output, it is very inefficient if used for power transfer. A full-wave rectifier is exactly the same as the half-wave, but allows unidirectional current through the load during the entire sinusoidal cycle (as opposed to only half the cycle in the half- wave). A full-wave rectifier converts the whole of the input waveform to one of constant polarity (positive or negative) at its output. Let us see our half wave rectifier example and deduce the circuit. So, we have seen that this rectifier circuit consists of two sources which have a phase difference along with two diodes. When V1 is positive, V2 is negative. Hence the top diode will be a short and the bottom diode will be an open. On the other hand, when Vs1 is negative, Vs2 is positive. Hence the bottom diode will be on and the top diode will be an open circuit.
A full-wave rectifier can be constructed using Center-Tapped
transformer – which give us two shifted sinusoids so that exactly one of the waveforms is positive at one time and two diodes. As compared to the half wave rectifier we use two diodes instead of one; one of the two diodes remains in conduction in both of the half cycles. At any point in time, only one of the diodes is forward biased. This allows for continuous conduction through load. Connecting Wires A Plug Single lead wire – 2m Three Nuts & Bolts 2-3 cm length Circuit board A Transformer (12 V) A Resistor p-n junction diode (4 nos) A LED Insulation Tape, Blades, Soldering Wax, Soldering Iron, Soldering Lead & Sand Paper Circuit diagram of a full wave rectifier : Take the transformer and attach it to one end of the circuit board. Attach the plug with the wire of desired length and connect it to the transformer AC. Now, take four diodes and connect the 4 diodes into a loop. Connect the anode of diode D1 to the anode of D2.
Connect the cathode of D2 to anode of D3 connect
the cathode of D3 to anode of D4 and connect the anode of D4 to cathode of D1. The output of transformers should be connected to A and C. Now, take two capacitor and connect its -ve terminal to negative and +ve terminal to +ve. And connect both the capacitors to B and D. Connect a resistor and a LED to the capacitor. Attach wire from the capacitors and connect it to the output device. When the AC is supplied to the transformer, it step down the 240V main supply to 12V. It has a capability of delivering 700mA. The 12 volts AC appearing across the secondary is the RMS value. The four diodes labelled D1 to D4 are arranged in “series pairs” with only two diodes conducting current during each half cycle. The four diodes labelled D1 to D4 are arranged in “series pairs” with only two diodes conducting current during each half cycle. During the positive half cycle of the supply, diodes D1 and D2 conduct in series while diodes D3 and D4 are reverse biased and the current flows through the load as shown below.
The Positive Half-cycle
During the negative half cycle of the supply, diodes D3 and D4 conduct in series, but diodes D1 and D2 switch “OFF” as they are now reverse biased. The current flowing through the load is the same direction as before.
The Negative Half-cycle
In subsequent Half cycles of the AC Current the above
process are repeated. In both the half cycles it is clear that current flows through the resistor in only one direction. Even though the voltage across load is unidirectional it will still contains a few AC components. This is filtered and made smooth using a capacitor, which filters 99% of the AC current. A resistor is then used to adjust the output voltage. Capacitor also nearly filters all AC components from supply and resistance is adjusted for the required output. As this is a simple circuit, two capacitors and one resistor are being used. The output Direct Current and voltage light up the LED and other source connected with it. On connecting a voltmeter to the output of bridge circuit 12V current is coming. Rectifiers are found in all power supplies that operate from an ac voltage source. Also the rectifier is used as a power supply unit. The rectifier converts the ac input voltage to a pulsating dc voltage. The filter eliminates the fluctuations in the rectified voltage and produces a relatively smooth dc voltage. The regulator is a circuit that maintains a constant voltage for variations in the input line voltage or in the load.