Difference Between Center Tapped And Bridge Rectifier

The process of converting the AC current into DC current is referred to as rectification. Rectification can be achieved by using a single diode or group of diodes. These diodes which convert the AC current into DC current are referred to as rectifiers.

Rectifiers are typically classified into two types, which include half wave rectifier and full wave rectifier.  All these rectifiers have a common aim that is to convert alternating current (AC) into direct current (DC).The full wave rectifier is further categorized into two types:

• Center tapped full wave rectifier
• Full wave bridge rectifier

What Is a Center Tapped Rectifier?

A center tapped full wave rectifier is a type of rectifier which uses a center tapped transformer and two diodes to convert the complete AC signal into DC signal. Load resistor, an AC source, two diodes and a center tapped transformer are the main components of a center tapped full wave rectifier.

The center tapped transformer is used to convert the input AC voltage into output DC voltage and therefore, when input AC voltage is applied, the secondary winding of the center tapped transformer divides this input AC voltage into two parts; positive and negative. The main advantage of a center tapped full wave rectifier is that it allows electric current during both positive and negative half cycles of the input AC signal. More importantly, the DC output of the center tapped full wave rectifier is made up of fewer ripples. The smoothness of the output DC signal is measured by using a factor referred to as ripple factor.

However, the main disadvantage of a center tapped full wave rectifier is that the center tapped transformer is very expensive and occupies large space.

What You Need To Know About Center Tapped Rectifier

1. Center tapped rectifier as the name suggest is requires a center tapped transformer (secondary winding).
2. The peak inverse voltage (PIV) of diode in center tapped full wave rectifier is twice the transformer secondary terminal voltage.
3. Center tapped rectifier uses only two diodes in its circuit.
4. The transformer utilization factor (TUF) is equal to 0.672
5. Voltage drop across the two diodes of center tapped rectifier is less when compared to bridge rectifier.
6. The transformer required in center tapped rectifier is bigger than that required in bridge rectifier in terms of kVA rating.
7. Center tapped transformer is economically efficient since it uses only two diodes in its circuit.

What Is a Bridge Rectifier?

A bridge rectifier is a type of full wave rectifier which uses four or more diodes in a bridge circuit configuration to efficiently convert the Alternating Current (AC) into Direct Current (DC). Bridge rectifiers are widely used in power supplies that provide necessary DC voltage for the electronic components or devices.

The rectifier efficiency of a bridge rectifier is almost equal to the center tapped full wave rectifier. The only disadvantage of bridge rectifier over center tapped full wave rectifier is in the cost involved in the set up.

The main difference between bridge rectifier and center tapped full wave rectifier is that, bridge rectifier produces almost double the output voltage using the same secondary voltage.

What You Need To Know About Bridge Rectifier

1. No center tapped transformer is required in bridged rectifier.
2. Peak inverse voltage PIV of diode is equal to the transformer secondary voltage. Thus this type of rectifier can be used for high voltage application.
3. Bridge rectifier uses four diodes in its circuit. This result to increment in the circuit complexity in case of the bridge rectifier.
4. The transformer utilization factor (TUF) is equal to 0.810 for bridge rectifier.
5. The voltage drop across the 4 diodes of bridge rectifier is more than the voltage drop across center tapped rectifier.
6. The transformer required in bridge rectifier is smaller than that required in center tapped rectifier in terms of kVA rating.
7. Bridge rectifier is economically inefficient since it uses four diodes in its circuit.

Also Read: Difference Between Half wave And Full Wave Rectifier

Difference Between Center Tapped And Bridge Rectifier In Tabular Form

Also Read: Difference Between Clamper And Clipper

Summary

Center Tapped Rectifier

• Number of diodes required: 2
• Transformer requirement: Center tapped
• Average value of current, Idc: 2lmax/pi
• Rms value of current, Irms: Imax/sqr root (2).
• Peak inverse voltage (PIV): 2Vmax
• Peak load current, Imax: Vmax/ (Rload+Rf)
• DC output voltage, Vdc: Idc xRload
• Rectification efficiency (max): 81.2%
• Ripple factor: 0.482
• Fundamental frequency of ripple: 2f
• Voltage regulation: better
• Transformer utilization factor: 0.692
• Form factor 1.11
• Peak factor: Sqr root(2)

Advantages Of A Center Tapped Full Wave Rectifier

• It only requires two diodes and therefore its circuit is not that complex.

Disadvantages Of A center Tapped Rectifiers

• The windings of the center tapped transformer must be tightly coupled in order to avoid voltage spikes when each transistor (on the center-tapped side) turns-off.

Bridge Rectifier

• Number of diodes: 4
• Transformer requirement : Not necessary
• Average value of current, Idc: 2lmax/pi
• Rms value of current, Irms: Imax/sqr root (2)
• Peak inverse voltage (PIV): Vmax
• Peak load current, Vdc: Idc X Rload
• Rectification efficiency (max): 81.2%
• Ripple factor: 0.482
• Fundamental frequency of ripple: 2f
• Voltage regulation: Good
• Transformer utilization factor: 0.812
• Form factor: 1.11
• Peak factor: sqr root (2).

Advantages of Bridge Rectifier

• Low ripples in the output DC signal.
• The rectifier efficiency of the bridge rectifier is very high when compared to the half wave rectifier.
• There is low power loss
• No center tapped transformer is required.

Disadvantages Of Bridge Rectifier

• Bridge rectifier circuit is very complex in nature. It requires four diodes.
• Power loss is high when compared to the center tapped full wave rectifier.