Activity for coquelicotâ€
| Type | On... | Excerpt | Status | Date |
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| Edit | Post #281653 |
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— | over 3 years ago |
| Edit | Post #281653 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Capacitor ESR vs. Impedance I'll try first to give a general introduction to the problem, then I'll switch to your particular questions. Passive linear components, like capacitors, inductors or resistors are not ideal. For this reason, they are often modeled electrically as a more or less complex circuit involving resistanc... (more) |
— | over 3 years ago |
| Comment | Post #281540 |
@Joel Reyes Noche. An excellent question! I would have give you a +1 if I could :-) (more) |
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| Edit | Post #281540 |
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| Edit | Post #281540 |
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| Edit | Post #281540 |
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| Comment | Post #281549 |
@Olin. Fig 32 ("basic connections suitable for many applications") and fig. 35 for example indicate to leave pin 3 and 5 not connected. It is evident that if I don't show a pin in a schematic, that means it is not connected, as is common in electronics. In a QA site, the criterion for "wasting your ... (more) |
— | over 3 years ago |
| Comment | Post #281540 |
@Joel Reyes Noche. Yes, I have a real AD8307, and I tried two from the five I've ordered. According to the datasheet (link in the question), output 4 is the "out" pin. (more) |
— | over 3 years ago |
| Comment | Post #281540 |
@Lundin. I don't know what is "spot market", but if that means "Chinese market", then yes. That question is also a way to know if I am understanding right the IC. (more) |
— | over 3 years ago |
| Edit | Post #281540 |
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| Edit | Post #281540 |
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| Edit | Post #281540 | Initial revision | — | over 3 years ago |
| Question | — |
Is this AD8307 fake? I am trying to test a AD8307. Here are my connections: AD8307 (pins not shown are left unconnected, and also pin 8). I get a quiescent output voltage at pin 4 of about 850 mV with respect to ground, which, to my best understanding, means that the IC is fake. What do you think? ADDED: ... (more) |
— | over 3 years ago |
| Comment | Post #281323 |
@Olin Lathrop. Thx for having pointing out this calculation mistake. What imported to me was the general idea, so I have not been careful. (more) |
— | over 3 years ago |
| Edit | Post #281323 |
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— | over 3 years ago |
| Comment | Post #281325 |
@manassehKatz.
"The likelihood is that the breaker will trip and protect the people, devices and wiring involved quite well".
This is a strong claim!. (more) |
— | over 3 years ago |
| Comment | Post #281322 |
You first decided in the question that the resistance is high, which is relative and incorrectly stated at the least (as explained at the beginning of my answer). Then you say "water is a danger for short circuit" which may be interpreted in several ways, the most obvious one being: "Why is water con... (more) |
— | over 3 years ago |
| Comment | Post #281322 |
@Kranulis. Speaking about quality, the title of your question is "Why is the resistance of water so high?" (which is a physics question involving quantum mechanics), and inside the text, the question is "why water is such a danger for short circuits if the resistance is so high?", which is unrelated ... (more) |
— | over 3 years ago |
| Comment | Post #281323 |
@Kranulis. Unfortunately, my answer exactly answer to your question. So, if that not what you expected, you have not correctly asked the question. Also, you haven't pinpointed in what it does not go in line to what was asked, despite my answer is essentially similar to that of manassehKatz. This and ... (more) |
— | over 3 years ago |
| Comment | Post #281322 |
Just to let you know: in this site, it is not forbidden for a user to have several accounts, but it is strictly forbidden to use them for up-voting yourself, or even worse, to down-vote an answer by more than one point. (more) |
— | over 3 years ago |
| Comment | Post #281323 |
I gave you a -1 (my first one since I know this site) because if you estimate that my answer does not answer to your question, it is evident for me that your question is not correctly asked. (more) |
— | over 3 years ago |
| Comment | Post #281323 |
Your question is "why water is such a danger for short circuits", and I have given at least 3 reasons. (more) |
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| Edit | Post #281323 |
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| Edit | Post #281323 |
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| Edit | Post #281323 | Initial revision | — | over 3 years ago |
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A: Why is the resistance of water so high and still so dangerous? I think your measurement instrument is fine. What is not is your understanding of resistance: there is nothing like this "resistance of water". In your case, the measured resistance depends on the distance between the immersed probes. The relevant concept is "electrical resistivity" or "volume re... (more) |
— | over 3 years ago |
| Comment | Post #281066 |
no 2. In what manner the higher required temperature affect the service life of the tip according to you? (more) |
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| Edit | Post #281094 |
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| Edit | Post #281094 |
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| Edit | Post #281094 | Initial revision | — | over 3 years ago |
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A: Why is it is always power consumption or power delivered more in usage? No. You use the right concept whenever you need to use it. There is no preference of "power" over "energy". For example, the energy stored by a cap is equal to ${1\over 2} C V^2$. This is often used in computations. It's also the energy you have wasted that you have to pay to your electricity... (more) |
— | over 3 years ago |
| Edit | Post #281092 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Why do DC/DC switching controllers seem to favour the buck-boost topology over similar ones like Cuk, SEPIC and Zeta? I think the point is simply that there are much more demand on the buck-boost topology than on the Cuk/Sepic ones. And there are GOOD reasons for that: Several years ago, I asked a question on the SE forum: "where are Cuk converters". You can read the excellent answer there. The main point i... (more) |
— | over 3 years ago |
| Comment | Post #281083 |
For me, a schematic (or even a basic shema) would help. (more) |
— | over 3 years ago |
| Comment | Post #281059 |
@Lundin. Thank you for the link. I will have a look. (more) |
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| Edit | Post #281065 |
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| Comment | Post #281065 |
OK. See the add in my answer. (more) |
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| Edit | Post #281065 |
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| Comment | Post #281065 |
@mrwavelets. A communication signal IS a load. I think you should explain how the output of the modulated carrier wave is supposed to be used (do you want to feed an antenna with the signal?) (more) |
— | over 3 years ago |
| Edit | Post #281059 |
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— | over 3 years ago |
| Comment | Post #281060 |
@Olin Lathrop. Thank you for your add, a strong argument indeed. In fact, I see no way the stray capacitance could be less than 1pF or so. Even if I keep only 1/20 of the signal, this requires an input impedance of 20 k Ohm at the best. I am doing research and research implies you try to discover som... (more) |
— | over 3 years ago |
| Edit | Post #281065 |
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| Edit | Post #281065 | Initial revision | — | over 3 years ago |
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A: 555 timer, PAM with digital signal The 555 timer has a maximum output current rating (for example 250 mA for the NE555, check your 555 version datasheet). So whether or not you have to introduce a mosfet depends on whether your application is current demanding or not. For less than 100 mA (say), you can connect directly your 555 to wh... (more) |
— | over 3 years ago |
| Comment | Post #281061 |
It is probable that the temperature of your soldering iron is too high. Try reducing the temperature (e.g. with a dimer), and see if this helps. (more) |
— | over 3 years ago |
| Comment | Post #281059 |
For the moment, I've found the opa695 that is best suited, but it has 70uA input current. Also, the big 50 Ohm load is a problem. (more) |
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| Comment | Post #281059 |
Not with those keywords. Will try and perhaps delete this question. (more) |
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| Edit | Post #281059 |
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| Edit | Post #281059 |
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