Testing ESR with an Oscilloscope
An oscilloscope can be used to check ESR by using a very simple test circuit. All you need is a square wave generator (a 555 timer will do!) and a few resistors. The details are at my web page at
http://octopus.freeyellow.com/99.html
There are some links to other related pages at
http://octopus.freeyellow.com/esr.html
Usually the kind of capacitors that have ESR problems are used to reduce voltage ripple in power supply lines. The result of increasing ESR is an increase AC ripple on the DC supply line and a scope can test for this, provided you can find a place for the test probes.
http://octopus.freeyellow.com/99.html
There are some links to other related pages at
http://octopus.freeyellow.com/esr.html
Usually the kind of capacitors that have ESR problems are used to reduce voltage ripple in power supply lines. The result of increasing ESR is an increase AC ripple on the DC supply line and a scope can test for this, provided you can find a place for the test probes.