ESR

Normally, a lower ESR is better. There is no magic number for what “correct” ESR is because it’s a rated value for them. The value should be less than a kΩ, and depending on the quality of the capacitor should probably be less than 100Ω. Identifying the type of capacitor and finding new examples with similar ratings online to compare to will be a helpful option here. Looking at similar capacitors from DigiKey, Mouser, etc and seeing what values the manufacturers rate them for can give you an idea of what “normal” is.

Here we take a look at the various and curious ways we can use an ESR Meter! Learn how to test and recognise bad capacitors, test and measure unknown inductors and even trace short circuit MOSFETS using an ESR meter

CHAPTERS
00:00:00 Intro
00:00:47 What Is ESR
00:05:06 Testing Capacitors
00:10:34 How Does ESR Meter Work?
00:12:00 Bad Capacitors (type 1)
00:14:19 Bad Capacitors (type 2)
00:16:56 Measuring Inductors
00:30:39 Short Circuit Finding In VRM
00:38:04 That’s Not A Knife!
00:40:04 Conclusion

An ESR Meter is a very useful tool – but a proper one will cost you about $40-50. So let’s see if we can build a simple ESR meter using a few components are that are easy to salvage from broken electronics. In this video I build the ESR meter from a circuit I found on the internet, then modify it to get it to work better and finally look at a few ways we could enhance it further while still keeping the cost to around $5

Let’s build an ESR Meter!

Chapters
00:00:00 Intro
00:01:00 PCBWay Shared Projects
00:04:00 The Original Schematic
00:09:15 Selecting The Salvaged Components
00:20:55 Building The Project Prototype
00:47:08 Testing The Original Circuit
01:05:24 The LER Modification
01:08:36 Testing The LER Version
01:12:07 Analyzing The Results
01:12:46 Calibration
01:18:53 The $1 ESR Meter
01:20:54 The LER ESR Meter V2.0