Learning op-amp and IC555 - Electronic Circuits Projects Diagrams Free

littletransistor · 15th October 2007, 04:49 AM

Hey there,

I'm learning opamp in my college course before, and I want to apply it to reinforce my knowledge. And also starting to pick up IC555 as well.

Is it possible if I can make a whole microphone + speaker (to amplify my voice) with the 741 opamp, with the mic directly into the input and the speaker to the output? From what I've seen through the net, they are really complex with the transistors.

Also, is it feasible to make an LED flasher out of op-amp by using a battery?

ericgibbs · 15th October 2007, 07:07 AM

hi,
For 555 data look here:
http://www.unitechelectronics.com/NE-555.htm

Also use Google.

littletransistor · 15th October 2007, 08:15 AM

Quote:

Originally Posted by ericgibbs

hi,
For 555 data look here:
http://www.unitechelectronics.com/NE-555.htm

Also use Google.

Thanks for the 555 tutorials.

Btw, I've searched through the Net for the op-amp multivibrator project - but they don't have any of those. Is that astable multivibrator (differentiator configuration) can be connected to 9V battery like IC555 as well?

ericgibbs · 15th October 2007, 08:45 AM

Quote:

Originally Posted by littletransistor

Thanks for the 555 tutorials.

Btw, I've searched through the Net for the op-amp multivibrator project - but they don't have any of those. Is that astable multivibrator (differentiator configuration) can be connected to 9V battery like IC555 as well?

Look here for op amp data: Application Note #31 has many examples,,,enjoy

http://www1.national.com/JS/searchDo...on%20note%2031

Post a circuit of what you have done so far.

**Krumlink** · 15th October 2007, 10:57 AM

Well this is probably what you had in mind
http://intranet.cs.man.ac.uk/Study_s...als/index.html
Enjoy

For 555's, go here
http://www.kpsec.freeuk.com/555timer.htm

Ha eric, I beat you to the kpsec site

audioguru · 15th October 2007, 03:02 PM

An opamp doesn't have enough output current to drive a speaker.
A power amp IC is used to drive a speaker.
A preamp (made with transistors or with an opamp) is used to amplify the lery low signal from a microphone.
Then the microphone drives the preamp which drives the power amp which drives the speaker to make acoustical feedback howling.

An LM386 little power amp can have a capacitor added which boosts its gain to 200 and then a microphone can drive it and it can drive a speaker.

The 555 oscillator can make the speaker beep if you want.

Hero999 · 25th October 2007, 04:58 PM

Also, use something useful like the TL071 rather than the 741.

speakerguy79 · 25th October 2007, 05:33 PM

Better yet an NE5532/5534. TL07x chips are usually fine but their common mode operation range doesn't extend all the way to their rails. This can cause latch up or other problems with the op amp in some rare instances. The AD712 is another one that does this too IIRC.

The 5532/5534 is cheap, low noise, and arguably still one of the best audio op-amps out there. If you don't care about DC accuracy (which they really suck at

) they are a great option.

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15th October 2007, 04:49 AM	(permalink)
littletransistor	Learning op-amp and IC555 Hey there, I'm learning opamp in my college course before, and I want to apply it to reinforce my knowledge. And also starting to pick up IC555 as well. Is it possible if I can make a whole microphone + speaker (to amplify my voice) with the 741 opamp, with the mic directly into the input and the speaker to the output? From what I've seen through the net, they are really complex with the transistors. Also, is it feasible to make an LED flasher out of op-amp by using a battery?

15th October 2007, 07:07 AM	(permalink)
ericgibbs	hi, For 555 data look here: http://www.unitechelectronics.com/NE-555.htm Also use Google. __________________ Eric "Good enough is Perfect" PIC tutorials: Gramo's: www.digital-diy.net/ Bill's: www.blueroomelectronics.com/

15th October 2007, 10:57 AM	(permalink)
Krumlink	Well this is probably what you had in mind http://intranet.cs.man.ac.uk/Study_s...als/index.html Enjoy For 555's, go here http://www.kpsec.freeuk.com/555timer.htm Ha eric, I beat you to the kpsec site __________________ MechTronics World of Warcraft is a disease

15th October 2007, 03:02 PM	(permalink)
audioguru	An opamp doesn't have enough output current to drive a speaker. A power amp IC is used to drive a speaker. A preamp (made with transistors or with an opamp) is used to amplify the lery low signal from a microphone. Then the microphone drives the preamp which drives the power amp which drives the speaker to make acoustical feedback howling. An LM386 little power amp can have a capacitor added which boosts its gain to 200 and then a microphone can drive it and it can drive a speaker. The 555 oscillator can make the speaker beep if you want. __________________ Uncle $crooge

25th October 2007, 04:58 PM	(permalink)
Hero999	Also, use something useful like the TL071 rather than the 741. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez

25th October 2007, 05:33 PM	(permalink)
speakerguy79	Better yet an NE5532/5534. TL07x chips are usually fine but their common mode operation range doesn't extend all the way to their rails. This can cause latch up or other problems with the op amp in some rare instances. The AD712 is another one that does this too IIRC. The 5532/5534 is cheap, low noise, and arguably still one of the best audio op-amps out there. If you don't care about DC accuracy (which they really suck at ) they are a great option.