Author Topic: Building an ESR meter  (Read 26271 times)

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Offline torch

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Re: Building an ESR meter
« Reply #15 on: May 31, 2011, 06:08:30 AM »
Is there any reason why the method of using a function generator and scope, as described here: could not be used at a higher frequency (say, 100KHz) to find the ESR of smaller value caps? (He is using a 1KHz wave and can only measure down to 10uF). Also, I note that he is using a 10v signal while the ESR meter designs all seem to generate a fraction of that (IIRC, Bob Parker blue ESR meter is 100mv output) so as not to turn on any semi-conductors in the circuit. Any reason not to turn down the output voltage to something similar?

I answered my own questions: it all works just fine. Larger caps show a virtually flat line with a very narrow spike at the start of each square wave input. A 0.47uf cap has a slight ripple waveform (with the aforementioned spikes). A 0.1uf cap produces a shallow triangle wave between the spikes. A 3pf cap passes the square wave virtually unchanged. Seems to work equally well in circuit as without.

So, I now have built an ESR with a component count of 6: 2 bnc connectors, 1 project box, 1 51 ohm resistor, 1 scope and 1 function generator  :D

Offline Mechatrommer

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Re: Building an ESR meter
« Reply #16 on: May 31, 2011, 07:54:53 AM »
mine is 5, minus the project box :P
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
everything that we are able to see do exist, but not everything that exist we are able to see.
sorry my english :palm:

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