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A review, teardown, accidental destruction, and modification of a cheap consumer product from American Science & Surplus.

[@MrCarlsonsLab]

Great review Eric! I see some #44 there, that's good stuff. Interesting little meter design with no return spring.

[@vwestlife]

The back of the line voltage monitor package claims "Temperature Compensated Circuit (will work during temperature changes of 0° to 100°F)". I'm sure it will work across that temperature range, but exactly how is it "temperature compensated"?

[@jackwhite3820]

+vwestlife Diodes, LED's and Zener diodes will have different temperature coefficients, by putting a normal diode in series with a Zener diode you can partially compensate their temperature coefficients. I guess by having all those diodes in series some temperature compensation occurs just by coincidence.

[@JeffersonClockWorks]

I have a PV system on my roof that is Grid Tied. There is a Net Meter outside that shows when I'm drawing or pushing power to the Grid.
I would like to monitor the power coming or going to the Grid from inside the house.
Any idea how the sensing circuit would work?
Al

[@Vynncent]

Is there a link to buy the calculator, I feel that I need it

[@christheother9088]

The magnetic replacement for the spring is interesting. Wondering if that contributes to the accuracy problems.

[@Alexelectricalengineering]

Very interesting ;) Thumbs up :)
Alex

[@ver64]

Cool review Eric, thanks