Lots of op-amps. Need ideas on what to do with em.

[pkshima]

Hi guys. I got lots of LM741 op-amps and LM324 quad op-amps.
I wonder if I can use them in any way in my robot or elsewhere.

What are they best for. do they make good IR proximity sensors etc ?
any other use you guys can think of ? I dont want to sell them and you wouldnt buy them too simply cos they are too cheap and easily available anyways.

I could never find out how people use them, they need bipolar power supply and the output is too weak to drive any device.

thanks in advance.

 

[chemelec]

The LM741 requires a +/- sipply, but the LM324 is typically just a Single Supply.

They are Older parts and not the best for Low Noise or High Speed applications, But for General applications in Audio or making simple oscillators, or applications just requiring voltage gains, they are Quite Useful.

No they do Not drive Power, But they Produce Voltage GAINS.
However by Adding a Few Transistors to the output of the 741, you can make a Simple Power amp.

Yes, you can use them for IR proximity sensors, etc.

There are Litterly Millions of Circuit that can be made with them.
BUT You need to be More Specific of what you want, if you expect someone to give you a schematic of a circuit for them.

Gary

 

[audioguru]

An old 741 doesn't need a +/- split supply. You just need to bias its inputs to half the supply voltage like this:

 

[pkshima]

LM741/LM324 based IR proximity detector ? anybody ?

 

[chemelec]

An old 741 doesn't need a +/- split supply. You just need to bias its inputs to half the supply voltage like this:

Yes I realize that, But Generally a 741 is considered as requiring a Split Supply and the 324 as only a single supply.
But the 324 can also operate from a Split supply.

 

[audioguru]

The dual LM358 and quad LM324 have terrible crossover distortion and poor high frequency response due to their extremely low power (in those days). The MC3317x's are also single supply, use a little more power but are much better.

 

[eblc1388]

The dual LM358 and quad LM324 have terrible crossover distortion and poor high frequency response due to their extremely low power (in those days). The MC3317x's are also single supply, use a little more power but are much better.

I saw on the NS website that a single 2K resistor, from output to either positive or negative power rail, would cure the crossover distortion. Never tried it myself yet.

 

[Nigel Goodwin]

The dual LM358 and quad LM324 have terrible crossover distortion and poor high frequency response due to their extremely low power (in those days). The MC3317x's are also single supply, use a little more power but are much better.

I saw on the NS website that a single 2K resistor, from output to either positive or negative power rail, would cure the crossover distortion. Never tried it myself yet.

They are commonly used in guitar amplifiers and PA equipment, it's highly likely that most of your CD collection include audio which has been through many of both IC's. It's also quite possible that your CD player itself uses LM358's?, they are common in the audio stages of CD players!.

Audioguru seems to be an 'audio snob' :lol: he doesn't like many of the commonly used components :lol:

 

[pkshima]

Hmmm great info on op-amps

So can I use them to build sensors etc for my robot ?
IR proximity detector etc. ?

 

[audioguru]

I saw on the NS website that a single 2K resistor, from output to either positive or negative power rail, would cure the crossover distortion. Never tried it myself yet.

Hi L. Chung,
It works only with a cap-coupled load impedance and feedback resistor much higher than 2k, but then the circuit isn't "low power" anymore so you might as well use a "regular" opamp that is without crossover distortion. It also works if the load itself is the resistor to ground with a single supply.

 

[audioguru]

Re: LM324 and LM358 low-power opamps.

They are commonly used in guitar amplifiers and PA equipment,

Hi Nigel,
Sure, their fuzzy sound is welcome for guitar amps. The PA equipment I work with uses opamps and circuit design much, much better than the LM324 and LM358. I designed PA equipment and testers for them with a S/N and distortion limit of 0.05% (not my choice) at full output. Many thousands were made and none exceeded the limit when using cheap but good TL072 audio opamps.

it's highly likely that most of your CD collection include audio which has been through many of both IC's. It's also quite possible that your CD player itself uses LM358's?, they are common in the audio stages of CD players!.

My cheap CD players have a frequency response flat to 20kHz with low distortion. They don't have the crossover distortion of LM324 and LM358 opamps. Those distorting opamps are also slew-rate limited above only 5kHz. Most cheap Japanese audio opamps have very low distortion and a bandwidth to beyond 100kHz!

Audioguru seems to be an 'audio snob' :lol: he doesn't like many of the commonly used components :lol:

He, he, he. Audio snob, who me? :lol: I don't use Burr-Brown (now TI) expensive opamps with their frequency response from DC to green light, and distortion of 0.00008%! The "audio snobs" are adding a DC bias resistor to their outputs like above to reduce their distortion so low that all the zeros won't fit on this page. I also don't use those expensive gadgets that are supposed to damp a CD's vibrations and also don't use very expensive Monster cables like the audio fanatics. :lol: :lol: