how to study and understand the application of a circuit diagram?

[ann123]

hi,
can any one help me read the circuit diagram with its application & how it is used.

Thank you.

 

[kam1787]

any diagram or a specific one?

 

[Ow@i$]

Try to be specific and it will be easier for others to understand and comment. Anyhow in general if the circuit is IC based then directly search those IC's & in their datasheet you may find what is the application and all that, rest is all your electronic understanding and concepts whereby you will conclude the reason behind the use of each capacitor and resistor etc.....

Cheers!!

 

[ann123]

this is one of the circuit,

 

[jpanhalt]

Input (U1) is an opto-isolator or optocoupler. It isolates the output circuit electrically from the input circuit:
https://en.wikipedia.org/wiki/Opto-isolator

Q1 provides the driving current to the output (Q2, Q3). The output is a Class B amplifier (aka push-pull, scroll to page 8):
https://www.ece.cmu.edu/~ee321/spring99/LECT/lect18mar17.pdf

John

 

[Audioguru]

It is a hopeless horrible circuit.
R3 does nothing and can be replaced with a piece of wire.
Since there is no negative supply and no output coupling capacitor then R6 and Q4 also do nothing and can be removed.

 

[Analog Ground]

It is a hopeless horrible circuit.
R3 does nothing and can be replaced with a piece of wire.
Since there is no negative supply and no output coupling capacitor then R6 and Q4 also do nothing and can be removed.

To be fair, R3, R6 and Q4 serve as valuable "forum fodder"!

 

[Audioguru]

To be fair, R3, R6 and Q4 serve as valuable "forum fodder"!

Wouldn't it be nice if somebody posts a properly designed circuit?

 

[ann123]

can u correct this circuit.



thank u.

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can u correct this circuit.



thank u.

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can u correct it .main thin is gnd,power lines

thank u

 

[FvM]

Since there is no negative supply and no output coupling capacitor then R6 and Q4 also do nothing and can be removed.

I don't agree regarding Q4. It might be intended to drive a capacitive load, e.g. cable capacitance.

You can't rate or correct the circuit without a functional specification. In this case input voltage, output load, required output voltage level and switching speed.

 

[chuckey]

Absolutely FvM!, it could be driving a long cable at 10 MBit data rate.
Frank

 

[Audioguru]

It could be driving the high gate capacitance of an N-channel Mosfet at a fairly high frequency.

Why does the student want the circuit corrected since there is no explanation about what is its input source and what is its output load?

Now its parts designation numbers are changed so the previous discussion about it is meaningless.

 

[Analog Ground]

About a possible capacitive load:
- Current limiting resistors should be on the collectors of the output transistors.
- The output voltage during switching may exceed the maximum reverse base-emitter voltage on both output transistors which is only 5V.
I think the circuit still needs a bit of work.
(Just an observation. The opto-coupler is slow with a rise and fall time of 5us. No 10Mbits per second or doing anything at a high frequency.)