Please make me undestand how to read "Datasheets" and how to obtain the required info

[crutschow]

One thing . . about LM 317T
How am I going to get to know that for what input I give to this IC, am going to have what value of output?
As in what I did practically was I connected LM317T IC and gave it an input of 52.4V DC , at its output terminal I obtained 51.9V DC .. . this was what i measured with the help of DMM
So how am I going to know these values from the datasheet? that for which value of input am i going to obtain that particular range of output? Please help me out here so that I may get to start to know how to actually use this IC and know which one is of my use

If you read and understood my previous post you would know the answer to your questions.

 

[netfreak]

um thankyou guys for all your help
Actually I am having this circuit with myself which works perfectly fine( am gonna attach the picture of the circuit diagram here with this post)

View attachment 61417
Im having the input from phone lines here btw*


Now what I really want to do is I want to replace the LED portion of this circuit and replace it with a mobile charger. Means I want to have an output of about 5.3V DC from the LM317T

 

[netfreak]

Please tell me how to obtain 5.3V DC and 500mA by using this above circuit. please help me out

 

[crutschow]

Please tell me how to obtain 5.3V DC and 500mA by using this above circuit. please help me out

Do you want a constant voltage or a constant current? You can't have both.

 

[netfreak]

um actually I want to have both :/ so I may get my cellphone charged . . .

 

[netfreak]

My basic aim is to charge my cellphone btw. . . .By using the above circuit & replacing the LED portion directly by mobile pin charger I am not able to charge the phone up though the voltage that I am giving to my cellphone is about 5.1V DC. So i guess the only reason due to which my cellphone doesnt get charged(despite of the reason that the voltage being given to the cellphone is perfectly 5.1VDC ) is the reason of low amount of current. That is the main reason I want to increase the value of current

 

[cr0sh]

@ netfreak

You probably could see my post above....Stop, think, learn please

As a Bachelor in Electrical(Power) Engineering, you should know better......I really cannot believe you are that clueless ????
Surely your degree would have provided you with some knowledge.

You having me on right????

If so, you have picked the wrong person to play games with.

I can easily believe it; in some countries ::cough:: India ::cough:: it seems like they have these "schools" with lofty sounding names that provide an "education" and a "degree" with a lofty title, but based on what you can see about the school online you wonder if or how they manage to heat/cool the buildings, let alone provide an education. In fact, in many cases it seems like the instructors are as clueless as their students, and skate by in their teaching by providing and learning-on-the fly from whatever 2-bit internet connection they can cobble up.

Granted, many of these schools and "universities" seem to be in very rural areas, and it's the best that can be offered to the population in the area. Some of them try very hard to give an education, but the resources for it just isn't really there. The students get a "degree", but it isn't worth much in the "real world". Some of the brighter ones are able to roll that knowledge into something better, and maybe a few stay on with the school to ramp up the next set of learners coming through. And they do come through - which is great in my opinion; some education, even sub-standard, is better than plain ignorance.

What I find really disheartening is that we have here in the US and in Europe a great education system, but due to costs and opportunities many can't afford to partake of it. Not only that, but (at least here in the US), there seems to be an active effort to undermine real education (at all levels) for the public. I wish we had the drive in our American society for education and knowledge in science and technology, mathematics, etc - to have the level of respect it truly deserves. Instead, scorn and disdain for it seems to be the norm much of the time...

 

[audioguru]

You are a THIEF!
You are STEALING power from the telephone company. But your "off hook" current is not much. Also your LM317 is connected wrong.

I am surprized that the telephone company does not detect that your phone line is "off hook too long" and has not disconnected your phone line.
If my phone is off hook for 1 minute then it gets a very loud beep-beep-beep sound for 1 minute then it gets disconnected.

Why is your phone line 115VAC? Mine is about 50VDC from their 48V battery without a load and is 120VAC when ringing into a high impedance.

 

[netfreak]

@ crosh
Man your totally right. Sadly that is true :/

@audioguru
I know its theft and all that crap that you have said btw!
BUT ALL I WANT TO DO IS HAVE A CLEAR CONCEPT that why things arent working, and if they arent working then HOW CAN I MAKE THEM WORK! because I believe that as being an engineer I should be able to MAKE THINGS WORK EVEN IF THEY CANT!

 

[audioguru]

As an engineer, you should know that your "circuit" was made to light many LEDs in series when powered from mains electricity that is 115VAC, not to light LEDs from a telephone line.

Your cell phone probably has a 1000mAh battery that is charged at 167mA for 6 hours, or charged at 250mA for 4 hours.
But an off-hook phone line has a current of only about 20mA so your cell phone will take 50 hours to charge if you can give it 5V.

 

[bountyhunter]

@ crosh
I believe that as being an engineer I should be able to MAKE THINGS WORK EVEN IF THEY CANT!

That qualifies you for a position as either an Engineering Manager or marketing Director.... not an engineer. We engineers are limited by the laws of physics.

 

[netfreak]

As an engineer, you should know that your "circuit" was made to light many LEDs in series when powered from mains electricity that is 115VAC, not to light LEDs from a telephone line.

Your cell phone probably has a 1000mAh battery that is charged at 167mA for 6 hours, or charged at 250mA for 4 hours.
But an off-hook phone line has a current of only about 20mA so your cell phone will take 50 hours to charge if you can give it 5V.

Ok Sir, and thankyou for your guidance regarding this If I have got some other questions then I'll definitely come and ask you people here around