Susan Brown

[Susan Brown]

1. Did you watch the new 2nd video in Unit 4? I show you how to calculate the heat generated by a load/resistance. The last way that I show you, right near the end of the video, is the one we recommend. Find the circuit current first, then calculate P for each load.

2. Req = 1/(1/80) + (1/480)… do you know how to complete that calculation? Or is that what you are needing help with?

[Susan Brown]

Hi Richard,
I sent you info in my reply to your reset request

[Susan Brown]

I just emailed you about 21.

For 4 and 5 – I assume you saw the explanations in the results?

What we are trying to encourage here is to always begin with the basics. A component, whatever it is, has an expected input and output. This component is described as being on the line cord, so one would expect 120v as both the input and output.

The complaint is no power. We state that the input is good (“After verifying that the washer is plugged in to a good power supply”), so the next step is to test the output of the component that is next in line, in this case, the noise filter. If it is in spec, then you move on. If not, then you take a closer look at that component.

[Susan Brown]

Check your email!

[Susan Brown]

Hi Andrea,

Not trick questions! Just based on what we show in the first video in this unit. When one circuit has a failure, it will be affected, obviously, but any circuits that are *in parallel* to it are completely unaffected.

The *total* current will decrease, however, because Total current equals the sum of the currents in the various parallel circuits.

[Susan Brown]

The 5vdc is communications voltage (the state of the door lock), not operating voltage. That is common – you’ll rarely see 5vdc as anything other than data/communications.

[Susan Brown]

Hi Richard,

I haven’t rewatched the videos in those units, but the answers are usually based on the specifications that you’ll find on the tech sheets, and we show you the most common examples.

For “What are two common operating voltages for door locks in computer-controlled washers?” the answers we are looking for are 120v and 12vdc. As I recall, those are the examples we show.

[Susan Brown]

This one is correct:
Time-temperature called Holding Temperature

You are close on the other one, but that’s not the right terminology. If you look at the video for Case Study 4, at around the 13 minute mark, you’ll see what the “over-temperature” situation (in other words, too high) is called.

Do you see what it is?

[Susan Brown]

Hi Richard,

If you watch the video on volume control, starting around the 8 minute mark, you’ll hear the description of the mechanical pressure switch. It does not have a power supply, since it does not communicate with a board (in other words, it is not an electronic part). It just switches 120v to the motor.

[Susan Brown]

Good to hear!

We are also going to be revising some of the other units in Basic Electricity within the next week. Keep an eye out!

[Susan Brown]

Hi Richard,
Sorry for the delay in replying.

The main point is that the polarity changes directly rapidly, and understanding what that means.

Here’s the precise way to describe that:

“AC current has 60 cycles per second. A cycle has a positive direction then a negative direction, so two reversals per cycle. This means current changes direction 120 times per second.”

[Susan Brown]

See the second video in the unit, about halfway through.

[Susan Brown]

😀

[Susan Brown]

You’ve been paying attention!

That dryer video is pretty old, before he fully realized the importance of using LoZ or a loading meter on AC loads and we dialed in our messaging about that. That basically came after seeing a number of techs at Appliantology get stuck in their troubleshooting because they didn’t realize what was happening.

So, yes, in that video he just had it set on DMM. He also has a depth of knowledge to know when ghost voltage is more of a concern. But he finally realized that the best practice is to just always use a loading meter/LoZ just to make sure you won’t get head-faked by the occasional ghost voltage/open neutral scenario.

AC Power voltage is the usual 120v or 240v power supply that most of the loads in appliances operate on.

Does that help?

[Susan Brown]

Thanks. We’ve been having a lot of problems lately with our emails landing in spam folders, etc. We don’t know of any issues with our system, but I think email in general is not behaving as reliably as it used to 🙁

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