"John Bachman" wrote in message
...
On Thu, 01 Jan 2009 14:04:45 +1100, Franc Zabkar
wrote:

On Thu, 1 Jan 2009 01:14:42 -0000, "Arfa Daily"
put finger to keyboard and composed:


"Franc Zabkar" wrote in message
...
On Wed, 31 Dec 2008 01:48:42 -0000, "Arfa Daily"
put finger to keyboard and composed:

My Bob Parker meter works at around 100kHz ...

Arfa

The following diagram and flowchart indicate that, at least for the
Mark 2 design, the capacitor under test is pulsed with 8us constant
current pulses repeated every 500us:

http://us1.webpublications.com.au/st...100895_3mg.jpg
http://us1.webpublications.com.au/st...100895_2mg.jpg

- Franc Zabkar

That does appear to be so. Without looking it up, I just had it fixed in
my
head that it was around 100kHz. With the fact that it is a highly
asymmetric
waveform, duty factor-wise, I guess that it's hard to quote it as an
actual
frequency. It's sort of 100+ kHz 'width' pulses, repeated at a frequency
of
2kHz ...

Arfa

Remember that they're also current pulses, not voltage pulses, so the
voltage appearing across the cap is a trapezoid. I don't know how this
compares with a meter that generates a sinusoidal test voltage,
assuming that's how others do it.

The Capacitor Wizard uses a 100Khz sinusoidal signal. The Bob Parker
design is as described - that is what is used in our Blue ESR meter.
Bob always represented that his method is the equivalent of a 100Khz
signal.


Ah. So that's where I got it from. Direct from Bob .... Arfa


Other designs are described in our comparison at
www.anatekcorp.com/esr_compare.htm

John
AnaTek Corporation