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General Category => Analog discussion => Topic started by: thanosgen on June 01, 2009, 19:50:25 PM

Title: help about lm741 or other amplifier.
Post by: thanosgen on June 01, 2009, 19:50:25 PM
i want to find this prices VOH, VOL, VUTP, VLTP, VHYS. Also i want to drawn the suitable circuit with the suitable prices of materials so that it gives the output.
(http://img193.imageshack.us/img193/4249/ljjlj.th.jpg) (http://img193.imageshack.us/my.php?image=ljjlj.jpg)

and this is the circuit that i want:

(http://img199.imageshack.us/img199/3681/010454.th.jpg) (http://img199.imageshack.us/my.php?image=010454.jpg)

the Vcc is not 8Volts.my mistake.i m sorry.this is that i cannot find the right prices for the resistors.can you help me?

Title: Re: help about lm741 or other amplifier.
Post by: kam on June 01, 2009, 19:59:39 PM
Hello Thanos.

Please in English if you may

Thanks
Title: Re: help about lm741 or other amplifier.
Post by: thanosgen on June 10, 2009, 17:48:09 PM
ok update it.
Title: Re: help about lm741 or other amplifier.
Post by: kam on June 10, 2009, 23:20:24 PM
;)


So, this is supposed to be a schmidt trigger circuit. I've got you right what you need  ;D

http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/schmitt.html (http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/schmitt.html)

Also, this link (http://rds.yahoo.com/_ylt=A0geursxFDBKovAA.B9XNyoA;_ylu=X3oDMTEzdWN1djQ4BHNlYwNzcgRwb3MDNARjb2xvA2FjMgR2dGlkA1FSVzJfMTA1/SIG=12ocnaa3j/EXP=1244751281/**http%3a//www.eng.mu.edu/~craigk/mechatronics_notes/Schmitt_Trigger.pdf) would be very good for you to read.

use the first link and play with the calculator. Use the circuit from that page instead. You have some parts in your circuit that i would not use (for example the capacitor).
Title: Re: help about lm741 or other amplifier.
Post by: thanosgen on June 11, 2009, 00:43:46 AM
the capasitor is for the noise in my signal.just ignore it.i read the second link but i didn't find anything useful.can you tell me witch mathematic types i use to find the resistors?
Title: Re: help about lm741 or other amplifier.
Post by: kam on June 11, 2009, 18:16:00 PM
No math type at all. Exeriment yourself.

You need the circuit to turn on at about 3.5V and turn off at 2V. Your Vcc is 8V. If you experiment a little bit you will find the values with the calculator.
If you badly need the formulas, right under the calculator there is also a link that says "Show expressions"... Follow it
Title: Re: help about lm741 or other amplifier.
Post by: thanosgen on June 12, 2009, 19:58:57 PM
i need to make this circuit in theory.thats i ask you.can you explain this with thoery types?
Title: Re: help about lm741 or other amplifier.
Post by: kam on June 13, 2009, 18:21:32 PM
The circuit is a comparator acting like a schmidt trigger. Follow the links from the page i gave you and everything is inside there. I could copy/paste the whole pages inside the forum but you can choose what you want. The operation, the maths, the description, everything is in there.


http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/schmitt.html (http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/schmitt.html)
Title: Re: help about lm741 or other amplifier.
Post by: spic0m on June 15, 2009, 18:47:19 PM
Quote
Also, this link would be very good for you to read.

This link doesn't work anymore :) ;D
Title: Re: help about lm741 or other amplifier.
Post by: kam on June 15, 2009, 20:28:16 PM
Quote
Also, this link would be very good for you to read.

This link doesn't work anymore :) ;D

It does :P