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New Blue ESR Kit

Shown with optional stand and croc clips.
Blue ESR Meter Kit

# BlueESR - ESR & Low Ohms Meter (KIT)
The above model replaces the old K7204/K7214 Kit

If you repair switch-mode power supplies, TV receivers, computer monitors, vintage radios, or similar equipment, and/or if you need to measure very low values of resistance, this project can save you lots of time and aggravation - as it has for so many other techs. It measures an aspect of electrolytic capacitors performance which is very important, but normally very difficult to check : the equivalent series resistance, or "ESR"

OK so it won't tell you the capacitance of a capacitor. You might ask what's it doing here. Please read the article below.

# BlueESRKIT $ 106.00

Canadian Dollars
(Kit comes with Regular Aligator Clips)

Replacement Z86 chip $ 24.95 Canadian Dollars
OPTIONAL Clips and Probes Available

# BlueESRassembled $ 132.00 Assembled Unit

BlueESR Croc Clips BlueESR Stand PARROT TEST LEAD CLIPS BlueESR Probes
Optional Croc Clip for BlueESR
$ 14.65 Canadian Dollars
Optional Stand for the BlueESR
$ 17.99 Canadian Dollars

# Parrot Clips
PCSSW2MB 2mm $ 9.95 pair
PCSSW3MB 3mm $ 9.95 pair
PCSSW4MB 4mm $ 8.95 pair
Optional Probe for the BlueESR
$ 18.70 Canadian Dollars

Some wise person once said, "The reliability of any piece of electronics is inversely proportional to the number of electrolytic capacitors in it", and I doubt that many service technicians would disagree.
Especially now that switch-mode power supplies (SMPS's) have been commonly used in domestic VCR's and TV's etc. for a decade or so, one of the most likely components to fail is the humble electrolytic. The symptoms can be as diverse as a VCR's playback picture swimming in tiny dots, up to SMPS's mysteriously self-destructing.
As a service technician you have probably been close to tearing your hair out because of the difficulty in determining which electrolytics were faulty and which ones were still OK in SMPS's and other equipment. You want to be able to check electrolytics in circuit, with the power safely disconnected.
Why not use a readily available capacitor meter? Because when electrolytics go faulty, they normally don't lose their capacitance significantly ( as is normally assumed ). Rather their equivalent series resistance (ESR) goes through the roof. Capacitance meters won't tell you this: about the best they can do is give a low reading if the electrolytic is nearly open.

About ESR...

So what is an electrolytic's ESR?
Electrolytics depend on a water-based electrolytic, soaked into a strip of porous material between the aluminum foil plates, to complete the outer electrical connection to the aluminum oxide dielectric coating on the anode foil.
The electrolytic has electrical resistance which, along with the (negligible) resistance of the connecting leads and aluminum foil plates, forms the capacitors equivalent series resistance.
Normally the ESR has a very low value, which stays that way for many years unless the rubber seal is defective. Then the electrolytics water component gradually dries out and the ESR creeps up with time. The electrolytic gradually acts more and more like a capacitor with it's own internal series resistor.

Heat makes it worse...

If an electrolytic is subjected to high temperatures, especially from heat generated internally as a result of large ripple currents, the electrolytic will start to decompose and the dielectric may deteriorate and the ESR will increase far more rapidly.
To make things worse, as the ESR increases, so does the internal heating caused by ripple current.This can lead to an upward spiral in the capacitors core temperature, followed by complete failure - sometimes even explosive!
The service life of electrolytics is approximately halved for every 10 degrees C increase in temperature and, surprisingly, many are only designed for a few thousand hours at their maximum rated temperature and ripple current. (A year is 8766 hours!)
Switch mode power supplies place quite severe stresses on filter capacitors. Because of their compact construction, temperatures are high and the capacitors have to endure large ripple currents.

Necessity is supposed to be the mother of invention, but desperation works even better.

Thanks for all your support since 1971
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