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Type: Posts; User: c_mitra

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1. ## Thread: Design of 45 degree slant polarizer

by c_mitra
Replies
10
Views
297

### Closed: Re: Design of 45 degree slant polarizer

You are still ambiguous. If the incident signal is 45 deg pol with respect to horizontal, and your antenna is vertical, you will not get anything.

On the other hand, if the signal is 45 deg...
2. ## Thread: Design of 45 degree slant polarizer

by c_mitra
Replies
10
Views
297

### Closed: Re: Design of 45 degree slant polarizer

I hope I understand the question.

If the signal is vertically polarised and your antenna is also similarly oriented (the dipole is vertical), it will receive at max efficiency.

The same antenna...
3. ## Thread: How to they calculated resolution of the photodiode

by c_mitra
Replies
6
Views
180

### Closed: Re: How to they calculated resolution of the photodiode

Resolution will depend on the original signal strength.

You need to look into the noise specifications. The user has to decide the acceptable signal to noise ratio. If you are passing the...
4. ## Thread: Design of 45 degree slant polarizer

by c_mitra
Replies
10
Views
297

### Closed: Re: Design of 45 degree slant polarizer

I do not get it.

The orientation of the antenna determines the component (horizontal, vertical or 45deg) that will be received. If the main dipole component is oriented at 45deg, it will receive...
5. ## Thread: Led project. Led on at nightime.

by c_mitra
Replies
14
Views
407

### Closed: Re: Led project. Led on at nightime.

There is a saying that once a disease is known it is half cured.

So, let me paraphrase the requirement.

You want a visible LED on during night time (say 8pm to 8am), right? or you want the LED...
6. ## Thread: Misconceptions and flaws noticed by the more educated...

by c_mitra
Replies
55
Views
2,087

### Closed: Re: Misconceptions and flaws noticed by the more educated...

True.

But every model has an objective; it may be clearly stated in the beginning (but often not) and is supposed to highlight one aspect.

Some models may focus on visual aspects while some...
7. ## Thread: Misconceptions and flaws noticed by the more educated...

by c_mitra
Replies
55
Views
2,087

### Closed: Re: Misconceptions and flaws noticed by the more educated...

Poor scientist! He should immediately change into constant velocity mode from constant step time.

But does the scientist really believe than man (or woman for that matter) cannot stand on two...
8. ## Thread: Design of 45 degree slant polarizer

by c_mitra
Replies
10
Views
297

### Closed: Re: Design of 45 degree slant polarizer

Are you talking about optical polarisers? For the visible range of the EM spectrum? Using glass slide plates?

Please provide more details.
9. ## Thread: Connection Servo Motor to PC

by c_mitra
Replies
4
Views
300

### Closed: Re: Connection Servo Motor to PC

And this part is simple; you need a 24V DC power supply. You can get 100's of power supply (readymade for you) with diverse specifications. Get one that meets your power requirement.

Certainly...
10. ## Thread: Misconceptions and flaws noticed by the more educated...

by c_mitra
Replies
55
Views
2,087

### Closed: Re: Misconceptions and flaws noticed by the more educated...

Linearity of resistance is not usually understood in terms of temp (which is an external parameter that must be held constant); it should be understood in terms of V and I.

If you plot V/I for a...
11. ## Thread: The simplest definition of VOLTAGE you can come up with

by c_mitra
Replies
14
Views
694

### Closed: Re: The simplest definition of VOLTAGE you can come up with

Wrong.

Every electric field is associated with a potential field (V=integral of Fdx over x to infinity). It has nothing to do with the number of charge carriers (by the way, what is a charge...
12. ## Thread: The simplest definition of VOLTAGE you can come up with

by c_mitra
Replies
14
Views
694

### Closed: Re: The simplest definition of VOLTAGE you can come up with

Seriously wrong.

Voltage is a potential. It has nothing to with electrons; it has to do only with the electric field.

The potential is defined and measured in terms of work. Hence voltage has...
13. ## Thread: Threading tungsten carbide rod

by c_mitra
Replies
35
Views
8,208

### Closed: Re: Threading tungsten carbide rod

Not quite correct.

You start with WC in the powder form. You cannot melt or cast that stuff. The powder is mixed with nickel or cobalt as binder. Then it is sintered (high temp and pressure) but I...
14. ## Thread: Threading tungsten carbide rod

by c_mitra
Replies
35
Views
8,208

### Closed: Re: Threading tungsten carbide rod

The weak magnetism is very likely due to nickel or cobalt that are used as binders.

The density test is quite definitive. You cannot change the density.
15. ## Thread: Misconceptions and flaws noticed by the more educated...

by c_mitra
Replies
55
Views
2,087

### Closed: Re: Misconceptions and flaws noticed by the more educated...

Every charge is associated with an electric field and flow of charge is associated with a magnetic field. Hence every AC circuit is related to electromagnetic principles (what you call...
16. ## Thread: How can I generate Sine wave from any periodic waveform that has low frequency?

by c_mitra
Replies
33
Views
883

### Closed: Re: How can I generate Sine wave from any periodic waveform that has low frequency?

right, but...

A square wave of 50% duty cycle has some symmetry and because of that even components (even harmonics) disappear.

But if you have a pulse sequence that have 40% (something not...
17. ## Thread: Threading tungsten carbide rod

by c_mitra
Replies
35
Views
8,208

### Closed: Re: Threading tungsten carbide rod

I too think so.

Tungsten carbide is about double the density of steel; you just take the weight of a similar sized bit and compare.

But if it is steel, you can slowly anneal the bits, thread...
18. ## Thread: How can I generate Sine wave from any periodic waveform that has low frequency?

by c_mitra
Replies
33
Views
883

### Closed: Re: How can I generate Sine wave from any periodic waveform that has low frequency?

You are right.

A square wave is an odd function and all the even harmonics are absent. But they are there for an arbitrary waveform.

Sorry for the oversight.
19. ## Thread: Display current location of the vehical

by c_mitra
Replies
7
Views
479

### Closed: Re: Display current location of the vehical

That is very strange; when I put the gps coordinates into the maps.google.com, I get my location accurately (within +/- 5 meters; rough guess).

Without gps, google can locate you using the towers...
20. ## Thread: Threading tungsten carbide rod

by c_mitra
Replies
35
Views
8,208

### Closed: Re: Threading tungsten carbide rod

Take care to avoid corona. They can drain significant energy from your setup...

21. ## Thread: How can I generate Sine wave from any periodic waveform that has low frequency?

by c_mitra
Replies
33
Views
883

### Closed: Re: How can I generate Sine wave from any periodic waveform that has low frequency?

I do not know what is the objective of the said exercise, but you can always use a bandpass filter to get a sine wave from any arbitrary waveform.

Of course if you want to have a variable centre...
22. ## Thread: "Frosting" on top of Ni-Cd batteries

by c_mitra
Replies
4
Views
234

### Closed: Re: "Frosting" on top of Ni-Cd batteries

These are NiCd batteries, right? The white powder suggests that the cell is leaking.

Test it to confirm: scrape a bit of the powder and put it on a clean glass plate. Add a drop of water; the...

by c_mitra
Replies
21
Views
893

### Closed: Re: explaining about RMS

For any symmetrical waveform, the total area over a complete period is always ZERO irrespective of the exact nature of the waveform.

Unless, of course, you are defining area as above. But then...

by c_mitra
Replies
21
Views
893

### Closed: Re: explaining about RMS

For a sine wave, both the quantities, integrated voltage waveform in one cycle AND the total area in one cycle are ZERO.

see, for example,...

by c_mitra
Replies
21
Views
893

### Closed: Re: explaining about RMS

Yes, you can see a paper by a real mathematician here:

https://www.improbable.com/2016/01/15/facilitating-the-perfect-golden-ratio-eyebrow-new-patent/

Of course this is a joke but the point...
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