ACHRNEWS

Going haywire? Sparks fly

April 26, 2000
In the April 10 issue of The News, several readers noted that some of the wiring diagrams accompanying the article on “Electricity 101” were flawed. We salute their sharp eyes, and hope their letters help clear up any confusion this seemingly basic article may have caused.

From a reader at Tringale Electric, Lexington, MA: “Concerning the diagrams, Figure 2 needs to be corrected in both A and B voltage drops due to the fact that the light, if it is a light, could not be arrived at these voltage drops. Assuming this is a light, I therefore question the values of the voltage in both diagrams. The only way these values could be arrived at would be to replace the light as shown with a single-pole switch.

“Figure 4: The connection shown physically on the cells does not conform to the diagram below (to the right). As I see it, cell 1 and cell 2 are looking into the internal impedance of cell 3. As shown, cell 1 and 2 could never contribute to a total output voltage due to the fact that cells 3 and 4 are of a different potential than cells 1 and 2 leading to the total output voltage expected. Looking at the schematic, this would work without question.

“Figure 5: Contact D — this wiring bypasses D completely, so D is of no circuit value. Figures 2, 4, and 5 do not contribute to a working knowledge of electricity as I see it. There are electrical evaluations better able to describe series and parallel networks.”

From Roger Seymour at TIF Instruments, Miami, FL: “I’m sure you’ll have many more comments on a couple of errors in your ‘Electricity 101’ article. Figure 4 is incorrect and very confusing. And in Figure 5, capacitor D is shorted out. In both cases, ‘aspiring technicians’ will have their understanding made much more difficult than it should be.”

Finally, from Dave Hickman, Dave’s Heating and Air, Sterling, VA: “I noticed that Figure 4 is wrong in the illustration, although its schematic is correct. The positive/negative connections on cell 1 are reversed in the illustration but correct on the corresponding schematic. “Otherwise the article is excellent at enlightening the novice. We enjoy The News tremendously.”