Activity for Olin Lathropâ€
Type | On... | Excerpt | Status | Date |
---|---|---|---|---|
Edit | Post #284046 | Initial revision | — | about 3 years ago |
Answer | — |
A: Inductance vs frequency No. An inductance is an inductance. One way to look at an inductance is as an impedance that is a function of frequency: Zind = ωL = 2πfL Where Zind is the impedance magnitude of an inductance, ω and f the applied frequencies, and L the inductance. When &omega... (more) |
— | about 3 years ago |
Comment | Post #283958 |
OK, but don't tell me here, <i>fix the question</i>. (more) |
— | about 3 years ago |
Comment | Post #283958 |
How coupling effects the series inductance is a good question, +1. However, it's ambiguous to talk about the inductance "of this circuit". Do you really mean the two inductors in series? Do you mean the inductors and resistor as view from the voltage source? (more) |
— | about 3 years ago |
Comment | Post #283956 |
No, 2(4/9) <b>is</b> dimensionless. That's what you wrote. (more) |
— | about 3 years ago |
Comment | Post #283956 |
Seriously!? Just read the whole post looking for errors. Obviously you haven't done this yet. (more) |
— | about 3 years ago |
Comment | Post #283956 |
Whether one can guess the units is not the point. It's still <b>just plain wrong</b> to equate a value of Volts to a dimensionless quantity. (more) |
— | about 3 years ago |
Comment | Post #283956 |
I've said this before, so this time you get a -1 right away. We do engineering here, where units are important. Every numeric value that is not dimensionless <i>must</i> be shown with its unit. Units must match on opposite sides of every equals sign. If not, the equation is wrong, just like if th... (more) |
— | about 3 years ago |
Comment | Post #283955 |
Much better schematic, +1. (more) |
— | about 3 years ago |
Comment | Post #283956 |
There several errors because it seems you copied and pasted this answer from your answer to a similar question about an inductor. You should carefully read over the whole post before posting, then sometimes again a while after posting. That will catch a lot of this sloppiness. (more) |
— | about 3 years ago |
Edit | Post #283936 |
Post edited: |
— | about 3 years ago |
Edit | Post #283936 |
Post edited: |
— | about 3 years ago |
Comment | Post #283936 |
Why would I want to do that? As far as I can tell, it answers the question correctly. What do you think is wrong? (more) |
— | about 3 years ago |
Edit | Post #283909 |
Post edited: |
— | about 3 years ago |
Edit | Post #283936 | Initial revision | — | about 3 years ago |
Answer | — |
A: Current and voltage of inductor For reference, here is your circuit properly drawn with component designators: The question is what happens when the inductor current starts at 0, then the switch is closed. The first observation should be that the current source and the two resistors can be reduced to the equivalent Norton... (more) |
— | about 3 years ago |
Comment | Post #283926 |
I told you before, always include component designators on your schematic. -1 for ignoring this requirement. Ping me when you fix it, and I'll undo the downvote. (more) |
— | about 3 years ago |
Comment | Post #283906 |
Oops. Yes, I meant to say "minimum". (more) |
— | about 3 years ago |
Edit | Post #283909 | Initial revision | — | about 3 years ago |
Answer | — |
A: Select resistor for a diode What the "appropriate" value of R1 is depends on what you are trying to achieve, which you haven't told us. Will this device be used in bright light, like outdoors, and the LED therefore needs to be as bright as possible? Is it an illumination source? Is it just an indicator, and it only needs to ... (more) |
— | about 3 years ago |
Comment | Post #283904 |
The equation you use that implies the LED current as a function of the voltage across it is stated nowhere in the datasheet. You should only go by what it says in the datasheet. Also 5 digits is absurd in this case, especially due to the high temperature dependence of LEDs in general. "295.05 &Ome... (more) |
— | about 3 years ago |
Comment | Post #283906 |
The general form of this answer is correct, +1. However, you shouldn't be using the typical forward voltage drop, but the worst case (highest) for the current you want. The resulting calculation that you show than results in the <i>minimum</i> resistance to not exceed the maximum current rating of ... (more) |
— | about 3 years ago |
Edit | Post #283901 | Initial revision | — | about 3 years ago |
Answer | — |
A: Diode like a frequency mixer A diode mixer exploits the fact that the voltage across a diode is the log of the current thru it, to a good enough approximation for many uses. Now note that multiplication can be performed by taking the log of two values, adding the logs, then doing the un-log (take the exponential) of the result.... (more) |
— | about 3 years ago |
Edit | Post #283693 | Initial revision | — | about 3 years ago |
Answer | — |
A: Thermal relief for through-hole on multi-layer PCB That's a rather strange thermal relief pattern. It's also not clear where the hole is supposed to be. A proper thermal pattern has a plated hole and annular ring around the hole as usual. Then there is a gap with only a few narrow bridges connecting the annular ring with the surrounding plane. ... (more) |
— | about 3 years ago |
Edit | Post #283663 |
Post edited: |
— | about 3 years ago |
Edit | Post #283663 | Initial revision | — | about 3 years ago |
Answer | — |
A: What is the difference between emitter and collector of a transistor? I see you already have an answer based on the device physics. I'll answer that this means in a circuit. BJT (bipolar junction transistors) do work in reverse, at least somewhat. Generally, the characteristics aren't as good, particularly the gain. However, in most cases you still get some gain ... (more) |
— | about 3 years ago |
Edit | Post #283659 | Initial revision | — | about 3 years ago |
Answer | — |
A: SPI modes difference "Stream" and "memory mapped" should be defined in the documentation for whatever microcontroller you are using. "Memory mapped" can mean different things. It might be just a different way of saying DMA, meaning the peripheral gets and puts data directly to memory buffers without code intervention... (more) |
— | about 3 years ago |
Edit | Post #283587 |
Post edited: |
— | over 3 years ago |
Edit | Post #283587 | Initial revision | — | over 3 years ago |
Answer | — |
A: $Q$ and $\overline{Q}$ in bistable multivibrator Whichever you choose. I notice that you deliberately made the gain of one transistor a little higher than the other. That is irrelevant. The positive and negative outputs don't depend on the power-up state. They depend on which way the outputs go in response to inputs, like SET and CLEAR. Yo... (more) |
— | over 3 years ago |
Edit | Post #283453 | Initial revision | — | over 3 years ago |
Answer | — |
A: A signal with one mode or with three or more modes with just one mode Others have already explained that "discrete" means a finite set of values, not just two. This is to point out that having just one "mode" (it seems you mean symbol) doesn't make any sense. A signal that can only ever be in one value is no signal at all since it can't carry ... (more) |
— | over 3 years ago |
Comment | Post #283361 |
I don't know. I thought it was a reasonable question and upvoted it. It is unfortunate that users can downvote something anonymously and without explanation. (more) |
— | over 3 years ago |
Edit | Post #283365 | Initial revision | — | over 3 years ago |
Answer | — |
A: Motor Controller - What might be the purpose of these resistors? Reasons this is sometimes done: To get higher power dissipation. To get higher voltage capability. To get lower parasitic capacitance. For 1 and 2 the "normal" answer is to use a resistor rated for the required power or voltage in the first place. However, there are some advantages t... (more) |
— | over 3 years ago |
Edit | Post #283331 |
Post edited: |
— | over 3 years ago |
Edit | Post #283331 |
Post edited: |
— | over 3 years ago |
Edit | Post #283331 | Initial revision | — | over 3 years ago |
Answer | — |
A: Adding resistance to varactor circuit in my schematic we must add R1 correct? No. Ultimately you are adjusting the varactor with a DC voltage that has a certain impedance. You can think of it as a Thevenin source. In your case, the DC voltage is created by the divider of Rs and Rv, then the impedance increased by R1. However, yo... (more) |
— | over 3 years ago |
Edit | Post #283242 | Initial revision | — | over 3 years ago |
Answer | — |
A: Is English translation of technical terms on-topic? I think such questions are OK as long as they are EE-specific. General purpose dictionaries often do a poor job with specialized technical terms, especially when they are the same or similar as regular words in either language. There can also be nuances how EE-specific terms are used in different c... (more) |
— | over 3 years ago |
Edit | Post #283213 |
Post edited: |
— | over 3 years ago |
Edit | Post #283213 | Initial revision | — | over 3 years ago |
Answer | — |
A: Division of binary numbers logic circuit I dont understand how to make a logic circuit which does that job:check if the divisors is greater and equal or less than the most left digits of the divident So think about it. Break it down into small chunks. Let's ignore the reason behind your question and try to make a digital block that com... (more) |
— | over 3 years ago |
Edit | Post #283172 |
Post edited: |
— | over 3 years ago |
Edit | Post #283172 |
Post edited: |
— | over 3 years ago |