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Re: Dave Sharpe Watt Meters

Terry, RWW

I was willing to inquire with several local fabricators about making raw
boards for
stuffing, then the legal death wish  :^C of liabilities was brought up by well-
meaning folks on the list.  The circuit has some clearance problems, especially
at 240VAC.  At 120V-at- 12A (1.4kW) the circuit is marginal.  Just remember
you only have 300 mils (0.3") between power line with HV transients and opto-
isolated analog (+/-15VDC) level outputs.

I built a single sided home brew board, and the circuit work flawlessly
when assembled, no modifications were needed at
all!!!  The circuit is significantly more stable on a single sided ground
planed board then a cobbled up perfboard...

I've been so busy at work, getting my son in college and working on my power
controller, I haven't had much spare time to consider this until perhaps
the fall...
Soon I will be laying out a "Super Wattmeter" which will have 50 segment
bargraph, high and low resolution input, 5-10kW FSD, Datel DPM, and
5 point adjustable high set point limits to operate a relay to shut down my
in the event of overpowering.  It is involved, complicated and expensive (about
$200), but cheaper then a Triplett programmable controller (at $700 ea), and
having an electronic "hand on the cord" to pull it with a sudden power surge is
comforting in the extreme.

Yes, I also know about the PIC development boards, yada yada yada.  However
I'm not knowledgeable in C++, I don't have an emulator or development system
(nor does the majority of the people subscribing to this list).  Besides, I
to do the measurement in hardware, at least then I KNOW where the problem
is, versus a hardware, firmware, software system...


Dave Sharpe, TCBOR
Chesterfield, VA. USA

Tesla List wrote:

> Original Poster: "rwall" <rwall-at-ix-dot-netcom-dot-com>
> Last year several on the list expressed interest regarding PC boards for
> Dave Sharpe's optical watt meters.   What's the status if any on these watt
> meter "kits"?