Scribd
Upload
124 views2 pages

Esr Tester For Capacitor

This document describes a simple circuit that can measure the equivalent series resistance (ESR) of capacitors. The circuit works at 100KHz using a bridge circuit to compare the ESR of a capacitor under test to reference resistors. If the capacitor is good, the bridge will remain balanced and the meter will show maximum current. A higher ESR will cause lower meter readings. Shorts or open capacitors can also be detected. Components, schematics, and operation instructions are provided. Measuring ESR can help determine if a capacitor is still functioning properly.

Uploaded by

andirahmantanjung
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
124 views2 pages

Esr Tester For Capacitor

This document describes a simple circuit that can measure the equivalent series resistance (ESR) of capacitors. The circuit works at 100KHz using a bridge circuit to compare the ESR of a capacitor under test to reference resistors. If the capacitor is good, the bridge will remain balanced and the meter will show maximum current. A higher ESR will cause lower meter readings. Shorts or open capacitors can also be detected. Components, schematics, and operation instructions are provided. Measuring ESR can help determine if a capacitor is still functioning properly.

Uploaded by

andirahmantanjung
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 2

HOME PAGE

ESR METER:
Equivalent Serie Resistance
Tester for capacitors

SEE ELECTRIC SCHEMATICS


The project came from an italian magazine (Nuova Elettronica N212);
it's very simple but interesting; I've built it and tested some capacitors, so I think it's very
useful: build it;
It measures the ESR (Equivalent Serie Resistance) of capacitor (electrolytic and not);
pratically you can see if a capacitor is good or not.
It's a bridge circuit that work at 100Khz;
there're the following possibilities::

1) The electrolytic capacitor is good: (low ESR) the bridge will stay balanced and the
meter will indicate the maximun current.
2) The electrolytic capacitor is not good:
(high ESR) the bridge will be unbalanced and that will cause the meter to indicate less
current; as less the meter will indicate as higher will be the ESR;
After few measure you'll be able to decide if a capacitor is good or not.

3) There is a short circuit in the electrolytic capacitor:


the meter will indicate the maximum current and the red LED will lamp; capacitor is not
good.

4) The electrolytic capacitor is broken:


the meter will not move. Capacitor is not good.
 
I've closed the circuit in a small plastic box inside wich there is the battery, the meter and
a ON/OFFswitch;
the meter will be 500 microA F.S. but I've used a 1 milliA one adding a small NPN
transistor as amplifier;

You will notice some interesting thing about capacitpor using this meter; for example low
value capacitor (1-10 micrF) have oftem higher ESR than high value one.
SEE ELECTRIC SCHEMATICS
 

Components:

R1=1K5
R2,R3,R4,R5=10K
R6=68K
R7=4K7
R8=12K
R9,R11=1K-1%
R10,R12=22-1%
R13,R14=1K
R15,R16,R17=47K
R18=15K
R19=680
R20=2K2
R21=20K TRIMMER
C1,C2=1 microF electrolytic
C3=1NF POLY
C4=100NF POLY
C5,C6=1microF POLY
DS1,DS2=1N4007
DS3=1N4148
DL1=LED
TR1,TR3=BC547
TR2=BC557
IC1=TL084
S1=SWITCH
73 de iz7ath, Talino Tribuzio
HOME PAGE
 

You might also like