I finally got round to making my capacitor ESR tester this week after finding a nice simple 5 transistor version. Unfortunately, for me, the design was only SMD so, I decided to replicate his schematic in Eagle PCB using a through hole component design. I will not be going into much detail regarding ESR or Equivalent Series Resistance Meters as, there is already plenty of other sources of information on the subject. Yet, every tinkering knows capacitors are guilty of a lot of sins in electronics. Capacitors love to throw red herrings! They can appear physically fine (no bulge), show good capacitance and hide in circuit, standing to attention like the Queens Guards hiding shorts and high resistance under their big hats. This is where the ESR tester can be a saviour, with the ability to test for "out of specification" high resistance, within the capacitor. They can also be used to test "in circuit", without the need to remove every capacitor in the circuit.

     Digital Volt Ampere Meter
     Curious C-Beeper
     ESR METER: Equivalent Series Resistance Capacitor Tester
     30V Volt Meter with PIC16F676
     Function Generator using XR2206
     Simple EMF Probe
     Special Edition Accurate LC Meter with Green Backlight LCD
     RF Inductance Meter
     ESR Meter / Transistor Tester
     Digital AC Voltmeter

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