741 op amp non inverting comparator demonstration circuit step by step build and explanation

[@zappafanman]

i'm trying to get back into electronics again after a 20 year absence. I found this explanation clear and extremely helpful - thank you - things are starting to flood back!

[@Electronzap]

That's good! There's a lot more to do now for a lot less money.

[@ADRIANNORMANNINA]

Sweet demonstration, helped me out, really nice

[@Electronzap]

Glad to hear, thanks for watching!

[@ElectroPrints]

I’m using a LM741 op amp in my circuit , but I’m having a issue with it. Powering with a 9v battery , +9v rail and ground for the other rail. For some reason when I put 3v into the inverting input and 0v into the non inverting input , the op amp output is about 1.2 v to instead of going to ground. Why would this be ?

[@Electronzap]

741 op amp has a dual suppy output, which means that it falls about a volt and a half shy of both the positive supply voltage and ground. A single supply op amp can output ground. And a rail to rail op amp can output the full range of supply voltage.

[@kel-A-3414]

Where's the video on the minuscule voltage generated by the body?

[@K_chiranjeev_G]

Great Video !

[@Electronzap]

Glad to hear, thanks for watching!

[@arijeetroy8747]

Hey, I need to you ask one question, suppose I am building non-inverting amplifier (using opam CA3130) with random gain, and I need to provide split supply, and I will going to provide spilled supply by opamp 741, so +Ve and -VE supply will be given to the CA3130 opam but ground of ca3130 will be provided by opam 741 virtual ground or I can provide the ground from any individual supply? please help me.

[@arijeetroy8747]

Buddy Please tell me which ground should I give?

[@Electronzap]

There's a number of ways you can split a supply for a virtual ground. The main thing is that you get a reliable voltage that is centered between a single supply, that can handle as much current as you need.

[@arijeetroy8747]

@@Electronzap i got your point, again I ask the question, I am building active bandpass filter from CA3130 opamp, and for +VE and -VE supply, I am providing supply by 741 opam, my question is IN Ca3130 rest of components also connected just like int he noninverting side high pass filter will connect ..etc, various components need grounds, so should I provide the ground from 741 opam named as virtual ground or from individual supply ground which is not connected with 741? The answer, please.

[@arijeetroy8747]

Buddy please Answer this question

[@Electronzap]

@@arijeetroy8747 All the components of a particular circuit should share the same ground. So if you use a 741 op amp to make a virtual ground, them everything connected to the CA3130 should use that 741 op amp output as ground.

[@gandsnut]

Presuming the 2 resistors & potentiometer values haven't changed from the preview video, one would expect those components are still showing a rise in temperature as seen before. Any idea what kind of power is being dissipated by the potentiometer? Might you know its power-handling rating? Thx.

[@Electronzap]

They are the same value resistors, and I used the same batteries as the other video I did, so about 16V (2 series rechargeable batteries close to 8V each instead of the 9V I put on the diagrams) across them so they are passing the same current and generating the same heat as my preview video. The trimpot got hotter than the resistors because it has more resistance (They are in series, so the same amount of current flows through all 3 of them). I believe, don't know for sure though, that it is 1/4 watt, as are the fixed resistors. There is about 2KΩ resistance total, 1K of it being the trimpot, so it will have about 8V across it (about 4V across each 470Ω resistors). 8V/1000Ω = 0.008A 0.008A x 8V = 0.064W so about 1/16W. Generally you want to only have a 1/4W resistors dissipate no more than 1/8W of heat to stay safe, so 1/16W is a really safe amount. I may do a whole video on this topic but very few people watch my power and thermal videos. Thanks for the comment!

[@GLu-tb1pb]

if we have a function generator instead, where would you recommend putting the wires?

[@kabandajamir9844]

So nice

[@karenjackson8265]

Excellent video! I'm using a 741 op amp with a single 1.5vdc supply voltage. I'm tying pin 2 to gnd. Pin 6 is staying at Vcc whether pin 3 is gnd or Vcc. Ideally I would like to apply .4vdc to pin 3 and get near Vcc at pin 6. I have two 741's with the same results. Any thoughts why the output is staying at Vcc?

[@Electronzap]

Thanks! I checked the datasheet for the LM741 and the uA741 op amps. According the the dayasheet I found, the LM741 says the minimum recommended voltage is a split supply of positive and negative 10V (a 20V difference). UA741 shows a recommended minimum of +5V and -5V (a 10 volt difference). 1.5V is probably nowhere near enough voltage for the 741 to do anything. I have been making videos lately using the LM358 op amp which is made for using a single supply down to only 3 volts.

[@karenjackson8265]

@@Electronzap Thanks for the quick response. I'm using a TI 741 and I couldn't find any minimum Vcc, only a max in the TI design engineering manual. I also tried 3v and 9v single supply with the same results. I'm going to dig up a LM358 and find a higher source voltage and see if a .4vdc voltage will trigger it. I will need to get the output back down to 1.5v with either a load resistor or voltage divider. Thanks again!

[@Electronzap]

It's not easy to finding the particulars of op amps and nobody I have come across explains it well in my opinion. I'm still spending tons of time trying to learn all the different options.

[@karenjackson8265]

@@Electronzap I did find in the front of the TI design engineering manual a Functional Index and it provides the minimum Vcc voltage of +-2v for the TI uA741 op amp. Of course this would still be a problem as I was looking at 1.5Vcc and a single positive power supply. I did have a National LM358 and watched the videos you have on it. Whether using a 3v or 9v battery supply, setting the potentiometer to output .4v on pin 6 only outputs .4v on pin 7. .4v is all I have available as my trigger to pin 6 for the application where I need this circuit. I'm sure I can locate a 5v source for the Vcc. There is probably a way to amplify the output of the op amp or find a different op amp that will provide near Vcc at the output when pin 6 is .4v. A Germanium transistor will switch at less than .4v when applied to the base. Keep doing your videos, every bit helps others!

[@Electronzap]

Glad to hear! Thanks for watching!

[@RK4CHRIST]

THis is an amazing video thank you so much I'm building an active band p ass filter and this clears things up a lot

[@Electronzap]

Glad to hear! Thanks for watching!

[@willyrivero470]

How can you make an adjustable power supply, volt and amp with this op amp? Thanks.

[@Electronzap]

Haven't built one yet. I'd google search "741 op amp variable power supply" to look for schematics.

[@willyrivero470]

@@Electronzap I would love to watch a video explaining how it (the op amp) works controlling the range of volt and amp in a power supply. If it could be possible some day 😊.

[@Electronzap]

Sounds good!

[@willyrivero470]

@@Electronzap Thanks so much. I'll be around 😊.

[@saroanvel9988]

Canu say the components u have used

[@Electronzap]

I'll see what I can do. :) I've been working more than I had hoped recently so not much time to devote to my channel.

[@mahmoudalawasheer9220]

@@Electronzap please do you have facebook

[@Electronzap]

@@mahmoudalawasheer9220 Sure do! facebook.com/electronzap/

[@willyrivero470]

Excellent video and explanation. Thanks a lot! New subscriber.

[@Electronzap]

Thanks for watching! Glad to hear!

[@jeetenderkakkar7570]

Hello sir How to make bomb with 741

[@Electronzap]

You'd have to consult the Bureau of Alcohol, Tobacco, Firearms and Explosives on that one. www.atf.gov/

[@terminatorx1846]

Thanks

[@Electronzap]

Thank you!

[@Vrgb]

👍

[@celtichongy]

Very useful, thanks for upload.

[@Electronzap]

Thanks for watching!

[@ammarhamdoun7856]

بسم الله الرحمن الرحيم من باب المذاكرة: هل من الممكن أن نقول أنَّ الخارج من المكبر هو جهد متغير؟ can we say that the output of comparator is ac voltage? because the average value is zero at the output وهل من الممكن أن استعمله في صنع العاكس مع مشاهدة هذا الفيديو؟ can i use it to create the inverter? kzbin.info/www/bejne/p4fIdoWKadOssJo اجتنب الموسيقى في المقدمة، try to avoid the music in the begging لا أعتقد i don't think so هل من الممكن أن أصلها على الفلتر مباشرة can i connected to the passive filter directly?

[@ammarhamdoun7856]

بسم الله الرحمن الرحيم electronzapdotcom هل تعلم ما نوع المقارن في هذا الفيديو؟ kzbin.info/www/bejne/p4fIdoWKadOssJo do you know which type of comparator are used ? kzbin.info/www/bejne/p4fIdoWKadOssJo is it lm358 ? i can use that or i can use what you mention in this video انتبه من الموسيقى avoid the music

[@ammarhamdoun7856]

بسم الله الرحمن الرحيم أعتقد لا أستطيع أنْ أفعل هذا هناك؟ i think you can not use this comparator there أريد جواب للسؤال الأول i need answer for the first question

[@ammarhamdoun7856]

بسم الله الرحمن الرحيم اسئلهم ask them إذا عندك الجواب أفدني if you have the answer, tell me

[@Electronzap]

That's a very cool video! Unfortunately, I have no idea how to answer your question.

[@ammarhamdoun7856]

@@Electronzap بسم الله الرحمن الرحيم جزاك الله خيرا Thanks bro a lot