What is ESR Meter?

All capacitors have a certain amount of resistance to the passage of AC current. ESR (Equivalent Series Resistance) is the sum of all internal resistances of a capacitor measured in Ohms. An ideal capacitor has ZERO ohms ESR. From the diagram below you can see a resistor in series with a "PERFECT CAPACITOR". The value of the resistor is called ESR. Electrolytic Capacitors have a tendency to increase its ESR overtime due to drying or corrosion. High ESR is a frequent problem in today's electronic circuit. Even a 1 or 2 ohms rise in ESR can cause complicated problems. Under normal conditions the ESR has a very low value, which stays that way for many years unless the rubber seal is defective, in which case the electrolyte's water component gradually dries out and the ESR creeps up with time. The increase in ESR increases both voltage drops within the capacitor and the heat, produced in the capacitors due to resistive heating. If you don't check for ESR, you may be in for a "TOUGH DOG" repair. High ESR is the first sign of a capacitor failure. High ESR will cause complete circuit failure, over heating of capacitor, loading of the circuit, overstressing of other circuit components and other undesirable effects.

Why should I use an ESR?

Because measuring an electrolytic capacitor with an analog or digital capacitance meter can MISLEAD a technician into believing that a defective capacitor is good. This can waste your precious time and you are unable to repair the equipment. Which means you can't charge your customer! If you don't test for ESR on the capacitor, you will always miss the bad capacitor. Normally, these bad capacitors have high ESR reading which your normal multimeter or digital capacitance meter can't measure. Only by using the ESR meter, you will be able to measure the ESR on the capacitor and you will not be fooled by capacitors with bad ESR. ESR meter can even work IN-CIRCUIT, which means you don't have to solder out the capacitor in order to measure it using normal capacitor tester, which would not be accurate anyway.

Do you know that ESR meters can perform other wonders besides checking the ESR of a capacitor? Some digital ESR meter have the features of checking:

» Low ohms resistor such as 0.22 ohm, 0.33 ohm and etc.

» Horizontal yoke coil winding of a picture tube, inductor and primary winding of a transformer ? If a shorted turn is present, the inductance drops dramatically and the meter will show the ohms reading.

» Horizontal output transistor (HOT) in a monitor or TV ? If an open-circuit reading is obtained, the short-circuit is elsewhere. If the short-circuit remains, the transistor is faulty.

» Short-circuit in the track, usually trace to the components - You can use the ESR meter to locate short-circuits on printed circuit boards by measuring the actual track resistance. If the reading increases as you probe further along the track, you know you're going in the wrong direction!

» Speakers, amplifier etc - The pulses have a fast rise/fall time, so it would probably make a crude RF signal injector as well.

» The condition of both the normal and rechargeable batteries ? Flat and faulty battery will have high ESR.

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

In The News:


pen paper and inkwell


cat break through


Obsolete Is A Dirty Word (Intel Pentium 64 Bit Microchip)

Get ready everyone, home computers are about to set new... Read More

Review: Implementing the Google Search Appliance in an Intranet environment

Our corporate intranet is a non-framed environment with both Lotus... Read More

Discover Everything About Wholesale Bar Code Reader And Software!

It is a given fact that buying wholesale would make... Read More

Types Of Laptop Batteries

Throughout the years there have been many technologies involved with... Read More

Adding USB 2.0

The process of adding USB 2.0 ports took no time... Read More

The Benifits of Assembling Your Own Computer

Thinking about getting a new computer, but with all the... Read More

Which Notebook Computer Has Your Name On It?

Notebook Computers Are Sexy!Granted, the notebook computer may just be... Read More

Coping with a Serious Data Loss from your Computer Hard Drive

Data loss is an expensive reality. It's a hard fact... Read More

Laptop Computers Instigate Classroom Revolution!

Have you noticed that laptop computers are beginning to dictate... Read More

Top Three Factors to Consider While Choosing a Data Center for Your Business

Data Centers are the core of the Internet. The computer... Read More

Flyback Transformer-How to Locate the ABL Line

Whenever there is a complaint about monitor contrast problem I... Read More

Flash Memory Part 2: MMC and SD

MMC and SDFlash memory is available in so many formats... Read More

Computer Hardware Preventive Maintenance Software

Computers often break down at the worst of all times.... Read More

Laptop and Notebook Theft Prevention

Laptops or Notebook computers are an expensive personal and business... Read More

A Guide to Refurbished IBM Laptops

IBM boasts a very large array of older and newer... Read More

Learn How To Diagnose Power Supply Problems

The Power Supply convert's your regular household current into low... Read More

Ten Ways (plus 1) to Save on Printer Ink and Toner Cartridges

Are you getting tired of the high cost of printing?... Read More

Ink Cartridge Recycling 101

Let's take a moment to think about the topic of... Read More

What Is A Crystal? And How To Test It

Crystal are use to keep the frequency of the clock... Read More

Rackmount Computer Keyboards

The other piece of vital equipment to accompany the rack... Read More

HIPPA Goes Mobile and Wireless for Hospitals and First Responders

It appears we need to further streamline health care and... Read More

Is A Laser Printer Right For Me?

The average home computer user definitely does not need a... Read More

Your Printer Is Out Of Ink -- Now What?

We've all been there. You're in the middle of printing... Read More

Ten Things Everyone Should Know about Ordering an Inkjet Cartridge Online

It is true. You can save a lot of time... Read More

Printer Cartridges - Step Back in History

You are working and trying to print out important documents... Read More

The Printer Cartridge Wars: Generic or Remanufactured Cartridges Right for You?

OverviewAs "generic", "remanufactured", and "new compatible" inkjet printer cartridges and... Read More

3 Easy Step To Locate A Real Bargain On Laptop Batteries

Looking for a real bargain on laptop batteries? How do... Read More

How to Save Money With Cheap Computers

We all know that computers change more then any other... Read More

Dusting Your Computer - Keeping it Cool

My mother always told me to dust, but I never... Read More

Ink Cartridges - A Humble Beginning

Computers and their accompanying printers were huge years ago. In... Read More

You Can Prevent Computer Slowdowns & Issues

Most people understand preventive maintenance like changing the oil in... Read More

Heliodisplay --Computer Video With No Screen

Science-Fiction meets reality with this new video display technology.The Heliodisplay... Read More

Advanced Tips on Speeding Up Your PC

Other then keeping your HDD free of viruses, spyware, and... Read More