Capacitance meter ranges

[gregmcc]

I've been googling around for a few PIC based capacitance meters. There's some very nices ones around but they only seem to do low ranges, like up to 100nF or 1uF

How come there's no meters (that I can find) around that measure up to 50uF or 100uF? Does no one measure those values or is it a limitation of pic based meters?

 

[gregmcc]

Ok - After some more googleing I found the following:
http://www.geocities.com/dariuskrail20/PICCapMeter.html

Measures from 5pF to 2600uF

 

[Hero999]

I suppose the reason is because no one really needs to measure those sort of values because they're normally used in applications like decoupling where the value isn't critical.

 

[RadioRon]

I suppose the reason is because no one really needs to measure those sort of values because they're normally used in applications like decoupling where the value isn't critical.

I think you are correct. In addition, the larger values are most often in larger packages which are well labelled and easy to read.

 

[3v0]

I suppose the reason is because no one really needs to measure those sort of values because they're normally used in applications like decoupling where the value isn't critical.

What about checking to see if they are in good condition ?

 

[Hero999]

Measuring the capacitance isn't always a good way of checking whether a capacitor is good or bad, a capacitor can read the correct value and still be bad. There are other factors like increased leakage and ESR that are far more important.

 

[3v0]

Measuring the capacitance isn't always a good way of checking whether a capacitor is good or bad, a capacitor can read the correct value and still be bad. There are other factors like increased leakage and ESR that are far more important.

I have am stereo amp with 60 cycle hum and was going to test it with a capacitance meter I built. You may have saved me a bunch of time. I looks like I need to fine a circuit for a decent ESR meter.

 

[Nigel Goodwin]

Or just hang an extra capacitor across the ones you have, and see if the hum disappears!.