Project #1 - Current Direction Stated Wrong

Snap Circuits® Jr.

Project #1 - Current Direction Stated Wrong

Postby ArgieFBFan » Wed Jul 26, 2017 1:30 pm

In Project #1's explanation (2nd paragraph), it states "... current flows from the batteries through the lamp and back into the battery through the switch." I believe that this backwards. Current flow is battery negative terminal - switch - lamp - battery positive terminal.

I base my belief on:
1. Numerous websites state that electrons flow out of a battery from the negative end
2. In the Student Guide, 1-3 Batteries and Experiments (page 9) show the battery as a water pump, sending the flow towards the switch
3. Good electrical practices would have one place a switch between the source and the device (such as a wall switch and ceiling light). The switch isolates the device from the source. If the current flowed first through the device, a short before the switch would allow the device to energized, thereby bypassing the control (and protection) offered by the switch.

I realize that ESC Experiments 1-101 Instruction Manual is now in Revision H, so I wonder if my observations are conceptually correct, but the printed explanation, while seeming in error to me, is actually correctly stated?
ArgieFBFan
 
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Re: Project #1 - Current Direction Stated Wrong

Postby ArgieFBFan » Wed Jul 26, 2017 6:04 pm

After a bit more investigation, I found the best and most thorough explanation ...

https://www.allaboutcircuits.com/textbo ... tron-flow/

Flow from the battery (+) through the components to battery (-) is conventional flow [per Ben Franklin]
Flow from the battery (-) through the components to battery (+) is electron flow [actual]

So Snap Circuits is only "guilty" of using both flow definitions: using conventional flow in describing the flow in Project #1, and using electron flow
in utilizing the water pump/water pipe analogy in the Student Guide.

Ultimately, the concepts of voltage, current, resistance, continuity, and even mathematical treatments such as Ohm’s Law and Kirchhoff’s Laws remain just as valid with usage of either style of electron flow notation.
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Re: Project #1 - Current Direction Stated Wrong

Postby lrico » Wed Aug 02, 2017 10:10 am

When electricity was first discovered, it was assumed to flow from positive to negative. Later discoveries in sub-atomic physics showed that it actually flows from negative to positive.
In the Electrical Engineering world, electricity is still assumed to be flowing from positive to negative. This assumption makes analyzing circuits easier, and every electronics book our engineers have seen follows this. The true direction of electric flow never comes up when you are analyzing circuits. Snap Circuits® is teaching about circuits and preparing children to be electronics engineers, so we follow the electrical engineering view.



Jerry Cecchin
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Elenco Electronics, Inc.
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http://www.snapcircuits.net
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Re: Project #1 - Current Direction Stated Wrong

Postby ArgieFBFan » Wed Aug 02, 2017 11:58 am

Thanks for taking the time to respond to both my initial question and my follow-up discovery. I agree that the majority of people with no electrical background will answer that electricity in a battery powered (DC) circuit flows (+) to (-) - and that educationally speaking, instruction, experimentation, and gained knowledge should build off of this intuitive foundation of plus to negative.

As a retired mechanical engineer, I came across numerous EE text and papers that taught from a electron flow perspective - but they were very clear that this was the approach they would use and that, depending upon one's earlier learning, the left-hand and right-hand rules previously learned *may* require the opposite hand to be utilized. And yes, the diode "triangle" will point in the opposite direction, among other visual clues that now mean the opposite. But this is all something that your age-group audience may have to deal with ten-plus years in the future.

I will point out that in your Student Guide (which I have found thus far to be an excellent source to answer the "how" and "why" to the Snap Circuit's "what"), that if, in using the water analogy illustration of an electrical circuit, the "pump" was moved from the lower right to the upper right and reversed from a CW rotation to a CCW rotation, that this would precisely represent the conventional current directional flow being explained in Project #1.

Your boxes proudly proclaim "AGES 8-108". I am 65 and I am thoroughly enjoying my time building the project circuits. Of course, I have added my Fluke 115 Multi-Meter to the completed projects to explore the mathematical side of the electricity and electronics - but that's how engineer retirees have fun!

Thank you again for your response - and for providing an excellent product for our next generation of engineers.
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