Rectifier efficiency


by dnyberg2
Tags: efficiency, rectifier
dnyberg2
dnyberg2 is offline
#1
Feb27-12, 03:13 PM
P: 66
Is it true that a full wave rectifier is more efficient than a half wave and if so why?
Phys.Org News Partner Engineering news on Phys.org
Fiber-optic microscope will help physicians detect cancer, diseases at early stages
Wind tunnel tests support improved aerodynamic design of B61-12 bomb
Smart sensor technology to combat indoor air pollution
NUCENG
NUCENG is offline
#2
Feb27-12, 03:44 PM
Sci Advisor
P: 916
Quote Quote by dnyberg2 View Post
Is it true that a full wave rectifier is more efficient than a half wave and if so why?
In simple terms, in the half-wave rectifier you throw away half of the AC signal by only usiing conduction in one polarity. The advantage is using fewer components (lower cost). The disadvantage is that for a given output voltage the diode must be able to conduct a larger load current (heat).
berkeman
berkeman is offline
#3
Feb27-12, 03:57 PM
Mentor
berkeman's Avatar
P: 39,575
Quote Quote by dnyberg2 View Post
Is it true that a full wave rectifier is more efficient than a half wave and if so why?
This is a trick question as stated, IMO. You need to give more context to the question, and give some definition of "efficiency".

vk6kro
vk6kro is offline
#4
Feb27-12, 07:06 PM
Sci Advisor
P: 4,003

Rectifier efficiency


If you took efficiency as just power out divided by power in, the half wave rectifier would be slightly more efficient than a bridge rectifier (if we used a bridge rectifier) because the bridge rectifier has two diode voltage drops while the single diode just has one.
Otherwise, there is not a lot of difference because the input power to a half wave rectifier is supplied in half wave bursts and most of this power is delivered to the output.

However if they really meant "how effective are the two methods?", then the full wave bridge circuit would win every time.
The diodes of a bridge rectifier are only conducting half as much current as a half wave rectifier.
The peak current used for charging the filter capacitor is lower because pulses are delivered twice as often.
The filter capacitor can be smaller for the same hum-out level.


Register to reply

Related Discussions
PV Diagram Problem (ideal efficiency vs actual efficiency) Introductory Physics Homework 2
isentropic efficiency vs polytropic efficiency of a gas turbine Aerospace Engineering 6
polytropic efficiency vs isentropic efficiency? Mechanical Engineering 2