Quantcast Figure 3-36.Full-wave rectifier with an LC choke-input filter

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
3-30 Figure 3-36.—Full-wave rectifier with an LC choke-input filter. It should be apparent that when the XC of a filter capacitor is decreased, it provides less opposition to the flow of ac. The greater the ac flow through the capacitor, the lower the flow through the load. Conversely, the larger the XL of the choke, the greater the amount of ac ripple developed across the choke; consequently, less ripple is developed across the load. This condition provides better filtering. Q24.   In an LC choke-input filter, what prevents the rapid charging of the capacitor? Q25.   What is the value usually chosen for a filter choke? Q26.   If the inductance of a choke-input filter is increased, will the output ripple voltage amplitude (Er) increase or decrease? An LC choke-input filter is subject to several problems that can cause it to fail. The filter capacitors are subject to open circuits, short circuits, and excessive leakage. The series inductor is subject to open windings and, occasionally, shorted turns or a short circuit to the core. The filter capacitor in the choke-input filter circuit is not subject to extreme voltage surges because of the protection offered by the inductor; however, the capacitor can become open, leaky, or shorted. Shorted turns in the choke may reduce the value of inductance below the critical value. This will result in excessive peak-rectifier current, accompanied by an abnormally high output voltage, excessive ripple amplitude, and poor voltage regulation. A choke winding that is open, or a choke winding that is shorted to the core will result in a no-output condition. A choke winding that is shorted to the core may cause overheating of the rectifier element(s), blown fuses, and so forth. To check the capacitor, first remove the supply voltage from the input to the filter circuit. Then disconnect one terminal of the capacitor from the circuit. Check the capacitor with a capacitance analyzer to determine its capacitance and leakage resistance. When the capacitor is electrolytic, be sure to use the correct polarity at all times. A decrease in capacitance or losses within the capacitor can decrease the efficiency of the filter and produce excessive ripple amplitude. If a suitable capacitance analyzer is not available, you can use an ohmmeter to check for leakage resistance. The test procedure is the same as that described for the input capacitor filter. So far, this section has discussed in detail the operation and troubleshooting of the basic inductive and capacitive filter circuits. For the two remaining types of filters, we will discuss only the differences between them and the other basic filters.


Electrical News
Friday Quiz: Bipolar Transistors
Remember basic transistor physics? Let's see if you really do....
eetimes.com
9 Top Tech from Electronica 2014
After 50 years, Europe's bellwether conference Electronica shows the state...
eetimes.com
Micron Expands IoT & Auto Memory Products
Micron expanded its offerings for embedded applications and the connected...
eetimes.com
Moore's Law Competitor Wins $150K Elevator Pitch Prize
Quilt packaging wins $150,000 prize for best elevator pitch explaining...
eetimes.com
Nexus 6 Vs. iPhone 6 Plus: Phablet Deathmatch
There's never been a better time to buy a big-screened...
eetimes.com
Europe vs. Google
Google may not give much thanks for the gift Europe...
eetimes.com
Stephen Hawking: How He Speaks & Spells
The technology that helped resurrect the life of Stephen Hawking...
eetimes.com
Sony's 3-Year Plan: Treading Water or Just Sinking?
Sony's three-year outlook for its mobile business "isn't aiming for...
eetimes.com
HMC Spec Update Signals Healthy Adoption
The release of the Hybrid Memory Cube specification 2.0, along...
eetimes.com
Power Week: Si-Based Power Discretes to Continue to Dominate Over Next Decade
Discrete power electronics are predicted to become a $23 billion...
eetimes.com
Book Review: Deadly Odds by Allen Wyler
This is a great read that will have you on...
eetimes.com
Supercapacitors: A New Hero in the Spotlight
Today's supercapacitors are being used to replace rechargeable batteries in...
eetimes.com
EEVblog #687 – EFTPOS PIN Pad Terminal Teardown
What’s inside a smart card pinpad EFTPOS terminal? Dave looks...
eevblog.com
Your Part in the Recovery
Engineers and innovators are central to the slow but ongoing...
eetimes.com
Motor Controllers Offer Improved Noise Immunity
Operating at 5V gives these digital signal controllers enhanced noise...
eetimes.com
NXP to Pick Up Its Missing IoT Link - Bluetooth Low Energy
In pursuit of the Internet of Things market, NXP Semiconductors...
eetimes.com
USB Oscilloscopes Get Beta Drivers for Open-Source Hardware
Pico Technology has released beta versions of drivers for BeagleBoneBlack...
eetimes.com
It's Alive! The 3D Printing of Living Tissues
Within a generation, we likely will not just hear of...
eetimes.com
Curiosity Killed the Cat (Just Call Me Mr. Curiosity)
Max desperately needs a cat deterrent, but how should this...
eetimes.com
Memory Design Articles: Diagnostics, Datacenters & Failures
Here's a roundup of recent design articles that are relevant...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +