Re: Win's ESR meter design

On Sun, 29 Jul 2007 11:58:56 -0700, john@xxxxxxxxxxxxxxxxxxxxx wrote:

[snip]

Given a choice, I'd be thinking of generating the sine from a 'walking
ring counter' and a few resistors.
8 sections could give 1% THD unfiltered and the "C" quadrature
component pickoff would at least have a chance of being only a few
degrees adrift, hence the "adj delay" being far less critical
considering the lags in the agressive LPF needed for the square wave.
Looking to Speff's 'superior' spec' it would also now be as easy to
pick off an "L" sync (ie LCR measure) or to inc/dec the frequency in
decades, to allow extending out the impedance ranges.

Why not generate a direct sinusoidal oscillator? Pretty trivial with
good OpAmps.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

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