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In order for loads to be in series, there cannot be any alternate path that electrons can take. Is that the case with the booster and the main, based on what you just said above?
Oops – my “yes” was to your first response
Yes! And does the same thing happen if you are the ignitor? And if so, why would any current flow through the main coil?
Okay – that is where your mistake is.
There is something you aren’t seeing that affects one of the loads.
Try doing the Zen trick on the Booster. Become the booster. Imagine you are reaching out for L1 and N with your hands. Can you get there directly or do you have to go through any other loads?
No- please answer the question I asked. If you don’t know the answer, just say so. I’m trying to step you through the thought process you need to go through to get to the correct answers
It is given clearly in unit 5. The rule of thumb, which is perhaps more important to know, is also shown on the third video. We also asked you a quiz question about it. Please look at that section of Unit 5, and let me know if something isn’t clear to you
Voltage drop occurs when current flows though a load.
The first question you need to ask yourself is: Do all 4 loads have current flowing through them, as the circuits are shown in the diagram? (With the detector switch closed) Please just answer that question for me
Hi Philip,
Yes, that is correct!
That is not correct, which is why I asked how you arrived at it. If I know what your thinking is, then I can see where your mistake is and help you better.
Do you think that the main coil is in series with some of the other loads? If so, then it would have to share the voltage drop with them. That would mean any loads it was in series with would not be able to drop 120vac.
Normally, to calculate voltage drop across loads in series, you would need to know the resistance of each load. Like you did in Question 4 on the midterm. But we don’t give you any resistances for Question 8, and we still say that you can give us a numerical answer for each voltage drop.
The key is accurately seeing the layout of the loads, given the state of the circuits as shown in the diagram.
A first question to ask yourself is: Do all of the loads receive current?
Let me know what you think.
and the booster is 30v
You mentioned the booster twice. Did you mean to say the main coil here?
What is your explanation for the 30vac?
By the way, if you watch that video I asked you to, he addresses the danger of thinking about “the path of least resistance.”
That’s the formula, and I can help you figure out how to use it correctly in a little bit. But first…
The rule of thumb is just putting into words what the equivalent resistance of parallel loads will be compared to the resistance values of the individual loads. Something like “the equivalent resistance will always be larger than the biggest load”. (that is not necessarily the answer – just an example)
This is arguably more important to know, because you can do quick evaluations of circuits using this rule of thumb that will help you as you’re analyzing a schematic.
First of all, what is the rule of thumb for equivalent resistance of parallel circuits? (It is explicitly stated in the video on equivalent resistance in Mod. 3, unit 5.)
Hi Josiah,
Yes – you have to score 90% or higher on EACH exam in the course. The Midterm is perhaps the most important one of all! It really pushes students to help them understand important electrical concepts. I’ll be grading yours soon and will email you.
Correct. The distance between each pulse (the “square waves”) will vary to do things like control the speed of a motor.
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