Testing Capacitor-How To Test A Capacitor When Breakdown Under Load

Home
>
Computer Hardware
>
Testing Capacitor-How To Test A Capacitor When Breakdown Under Load

Testing Capacitor-How To Test A Capacitor When Breakdown Under Load

Have you ever come across power problem where once you switch on the power supply and the fuse blow? You have checked all the components in the power (primary) and secondary section and all the components seems to be ok! Where is the fault? A fuse blown are usually caused by a shorted bridge rectifier, defective posistor, power transistor or FET, shorted primary winding of switch mode power tranformer, shorted secondary diode and etc. But in this article i'm gone to show you another secret of electronic troubleshooting tips.

I got frustrated as to where is the cause of power problem. Everytime when i switch on the power supply the fuse blow immediately (the fuse became dark color and this indicate that there is a major short circuit in the power supply). I have checked all the components in the power supply and can't find the culprit! What i do is i desoldered all the suspected parts one by one and replaced with a known good component. I eventually found the caused of the power supply problem. Guess what? It was the main filter capacitor (220 microfarad 400 volt). After replacing the filter cap the power supply worked perfectly fine. I begin my detective work to find out why this capacitor can caused the fuse to blow eventhough i already confirmed it ok with my meters.

The meters that i used to check the filter cap were analog meter, digital capacitance meter and esr meter. In this article i will not explain about how to check capacitor or testing capacitor and how capacitor work. I believed most of you know how to check capacitors and also generally using this type of meters. Measured with analog it showed capacitor charging and discharge, with digital capacitor tester it showed around 220 microfarad and with esr meter it showed low esr reading!

This proved that the bad capacitor breakdown when under full operating voltage. Then, how do i confirm that this filter capacitor is faulty? By using an analog insulation tester. When i connect the faulty cap to the meter and press the go button-it showed a very low resistance and this is the proved of short circuit between the plate when voltage applied! There is nothing to do with bad electrolyte. A good capacitor will just showed a charge and discharge in the insulation meter just like you are checking a capacitor using analog multimeter. In the market there is quite a number of ranges that you can buy. It has the range of 50v, 100v, 250v, 500v, 1000v and even 5000v! If you want to test a capacitor of 100 microfarad 160v then you have to select 100v. If you select 250v, it will blow your capacitor that is under test.

If you have the SENCORE TEST EQUIPMENT such as the sencore lc meter LC102 OR LC103, these meters have the capabilities of checking any type of capacitors with four tests:
-testing for capacitor values
-checking for leakage
-equivalent series resistance (ESR) and
-Dielectric absorption

It can check aluminum electrolytic capacitor, film capacitor, ceramic, high voltage capacitor and etc.

Conclusion-Different capacitor manufacturer produced different type of quality of a capacitor. Perhaps the bad capacitor that I encountered are from the lowest grade one. A capacitor failure when under load is very rare. Using ESR capacitor meter alone can solve most of the electrolytic capacitor problem.

Jestine Yong is a electronic repairer and a writer. For more electronic repair information please visit his website at http://www.noahtec.com/electronic-repai r-articles.htm

In The News:

SafeNet's Luna EFT Hardware Security Module Achieves PCI HSM Compliance
MarketWatch (press release)
BALTIMORE, May 24, 2012 (BUSINESS WIRE) -- SafeNet, Inc., a global leader in data protection, today announced that its Luna EFT Hardware Security Module (HSM) has achieved PCI HSM compliance. SafeNet received this certification in advance of the ...

and more »

Chattanooga Times Free Press
Golf Mocs aiming for more hardware
Chattanooga Times Free Press
He didn't miss anybody handing Mocs coach Mark Guhne a plaque for winning, or somebody handing Stephan Jaeger hardware for earning medalist honors at the Club at Olde Stone in Bowling Green, Ky. "We'll have to get that fixed," said Hart, ...

and more »

Co.Design
It's Official: Google Is Now a Hardware Company
BusinessWeek
Woodside says Google also plans to use its new hardware division to produce smartphones and tablets that set the pace of innovation in the mobile business. “This is a huge opportunity to really show what Android can do in a well-designed, well-packaged ...
Google becomes hardware company with $12.5B Motorola buyComputerworld
Google becomes hardware company with US$12.5B Motorola buyAustralian Macworld
Google delves into hardware, buys Motorola Mobility for $12.5 billionTechSpot
Co.Design -Washington Post -FierceMobileIT
all 536 news articles »

IceWEB Wins DataCentre Storage Hardware Product of the Year Award
MarketWatch (press release)
IceWEB.com , a leading provider of Unified Data Storage systems for cloud and virtual environments, announced that it has won Storage Hardware Product of the Year Award in the 2012 Data Centre Solutions Awards. In a competitive selection process ...

and more »

Jagran Post
Report reveals fake chips in US military hardware
EDN.com
LONDON -- More than a million suspect counterfeit electronic components have been used in 1800 separate cases of bogus parts affecting US military hardware, according to a report produced by the Senate Armed Services Committee.
Fake millitary hardware concerns USJagran Post
Chinese counterfeit parts in US military hardwareThe Voice of Russia
Chinese counterfeit parts infiltrating US weapons systemMoneylife Personal Finance site and magazine
AllGov
all 197 news articles »

Idaho Mountain Express and Guide
Soccer teams haul hardware home from Boise
Idaho Mountain Express and Guide
Two Sawtooth United FC youth soccer teams brought first-place hardware home from the Idaho Youth Soccer Association's Director's Cup May 18-20 in Boise. The U-16 boys (3-0-0) scored 13 goals in three games led by Jose Ortiz (4 goals) and Andrew Graves ...

IceWb Wins DataCentre Storage Hardware Product Of The Year Award
Data Storage Connection (press release)
IceWEB.com, a leading provider of Unified Data Storage systems for cloud and virtual environments, announced that it has won Storage Hardware Product of the Year Award in the 2012 Data Centre Solutions Awards. In a competitive selection process ...

and more »

Seagate to acquire hardware maker LaCie
MarketWatch
Seagate has agreed to buy a controlling interest in LaCie from the European computer hardware company's chief executive, Philippe Spruch, and his affiliates for around EUR4.05 a share in cash. The offer, which would give Seagate control of 64.5% of ...

and more »

The Mary Sue
Lego for girls, this time hardware-hacker style
CNET
For Limor Fried, a hardware hacker and leader in the booming maker and do-it-yourself movements, there was never a question of waiting for someone else to jump in and do a better job of inspiring girls than Lego has done with its widely-panned Lego ...
Limor Fried, Hacker, Maker, and Owner of Adafruit Industries Designs Legos for ...The Mary Sue

all 9 news articles »

IBNLive.com
Google's 7-Inch Tablet: $199, Coming In July?
InformationWeek
The device will probably be sold directly to consumers via the new hardware section in the Google Play Store, where Google already offers the Galaxy Nexus for $399. Google launched this new hardware sales portal last week, where it will sell other ...
Google Said To Ready 7-inch Tablet For July RetailInvestor's Business Daily
Google, Asus to ship Nexus tablet in JuneIBNLive.com

all 68 news articles »

Google News