need help in reading datasheets

[black_rider]

must known circuits

For example I give pdf links to some multichanel optocoupler**broken link removed** and some darlington transisor array https://www.farnell.com/datasheets/7944.pdf

Now on datasheet there are a lot of data but what do I need to know?
For optocoupler input I assume that I need to know max current through photodiode and its resistance so I can calculate the needed resistance for a resistor that I need to add (input will be 12V). For the output I assume I need to know max continous collector-emitter current and voltage, so I know how high voltage I can bring to collector and how much current will be drawn through collector emitter.

What about darlington array. I assume that I need to know max continuos collector-emitter current and voltage. Do I need to know max base current voltage?

Can someone also write down the numbers since I am not able to get them from the datasheet.

 

[INS-ANI]

how to read datasheet

Electronics for you had a two part articles few months ago on reading datasheet. Try to fetch the mag.
or else try google.

 

[haker_fox]

how to read datasheet

You must know what you must know Roughly speaking, making any circuit you have to understand how it works. Which troubles can be there. To know all these you must have some experience.
I recommend post here your circuit and ask any questions with respect to it.

 

[black_rider]

Re: how to read datasheet

You must know what you must know Roughly speaking, making any circuit you have to understand how it works. Which troubles can be there. To know all these you must have some experience.
I recommend post here your circuit and ask any questions with respect to it.

I thought that explain how do I understand now I am just asking if that is correct. I don't know why is so hard to post a short answer if you know it, for example if someone will be asking what he/she must know about a resistor for instance I will tell that you must basicaly know the resistance and rated power - I am asking this for optocoupler and darlington array.


And I did post my circuit schematics here (it is wery base) but I did, not get any response.

Over the all, I didn't get answers to any of my questions I post on this forum!

 

[haker_fox]

Re: how to read datasheet

if someone will be asking what he/she must know about a resistor for instance I will tell that you must basicaly know the resistance and rated power - I am asking this for optocoupler and darlington array.

And he (she) must basically know the resistor's tolerance As you see it's difficult to give such answer.

 

[siongboon]

Re: how to read datasheet

Hi,

The datasheet contains a lot of data,
but you need not read them all.
You just need to get what you need to know.

I understand why many find it really difficult to explain,
because there is no answer.

Basically every components have it's properties.
Typically a student looks at the component
base on the followings,
resistor - ohm
capacitor - capacitance
inductor - inductances

As you do more and more circuit,
you will realised that sometimes your
circuits don't work as it should be.
You might realised that there are more
properties other than those typical as above.
You look for more into the component.
Your requirement on the component rises.
resistor - ohm, watt
capacitor - capacitance, voltage
inductor - inductances, current rating

It would for most of your circuit.
Most of the time it works.
When you deploy it in another environment, it fails again.
You troubleshoot and learn that
the component temperature does not meet your expectation.

And eventually you might realised that all the data
are important. Some information are more important than the other.
Some information you might never ever need to care about,
but can be very important parameter to another engineer in his design.
It really depends on how you are using the component.
What are you using that component for.?
For some project, you look only for a few parameters.
For more precision project, you analyse deeper.

And how do you know what is important to your design?
Do hands on and practise, practise, practise.
Circuit not working, find out why.
You learn more and more about the component behavior
hence the reason for certain type of failure.
You become more and more proficient for your future design,
because you learned how to select the component for your application.

I guess by now, you should understand why it is difficult to answer your question.
It is similar asking people, how to read the English book.

Go get your hand wet. Damage as many component
as you can and understand why it does not work the way you think it should.
I learn a lot about electronics even burning a simple wire to red hot.
I always learn something by spoiling something.
Be fascinated by every discovery and enjoy the process of learning.

Best Regards,
Siong Boon

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