Headphone amplifier using LM324, is it possible?

I have been scouring the web looking for a possible circuit for this chip. just one input and one output. i cant find anything, is it possible??

Question by MCW1989   |  last reply


Can I use 741 op amps instead of 1 LM324 in a heart rate sensor?

Http://makezine.com/video/visualize-your-heartbeat-with-this-homemade-pulse-sensor/

Question by DangerousTim   |  last reply


VU Meter Help?

I can only find an LM324 for a U meter. and the only schematic i could find was confusing....http://www.google.com/imgres?imgurl=http://www.zen22142.zen.co.uk/Circuits/Audio/Vumeter.gif&imgrefurl=http://www.acidmods.com/forum/index.php%3Ftopic%3D35382.0&usg=__JKJHEVkfZz92hhYo8rDxJaU9Roc=&h=401&w=407&sz=10&hl=en&start=0&zoom=1&tbnid=BowIq_ZQanGTBM:&tbnh=134&tbnw=138&prev=/images%3Fq%3Dlm324%2Bvu%2Bmeter%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D1440%26bih%3D807%26tbs%3Disch:1&um=1&itbs=1&iact=hc&vpx=124&vpy=167&dur=818&hovh=223&hovw=226&tx=139&ty=123&ei=mrB9TLTbDYSClAffhOjrCw&oei=mrB9TLTbDYSClAffhOjrCw&esq=1&page=1&ndsp=28&ved=1t:429,r:0,s:0.....<br> So if someone could either explain that circuit or help me with a new one, I'd much appreciate it!<br> <br> THANKS!

Question by fretwreckef94   |  last reply


is this usable as a sond amplifier? Answered

I have this lm324 chip from a old stud finder, i searched for a datasheet and found this: http://www.national.com/ds/LM/LM124.pdf it says a op amp, so will it work as a audio amp? sorry. i have never used ics before, and i dont know how to really read datasheets much

Question by zack247   |  last reply


How to add a op amp to this circuit?

I built this circuit a while ago but the only problem i have with it is that i have to use electronics like my iPod, laptop, or anything with a high volume output. So I started reading about op amps and hwo they "jack up the signal" and I stated wondering could I somehow integrate it into my circuit so that my audio input is higher therefore allowing me to use my cellphone, tablet, and e.t.c? Currently I have a LM324 Quad amp i know fr sure i wont need all those pin. I also have a tip31 and 2N3904 transistors.

Question by tramont   |  last reply


rgb led and 1 analog input? Answered

Im trying to make an rgb led light up in different colors to based on the analog input, for instance a "potentiometer" or equivelent like the lm324 controlling the input causes the input to go higher the red turns on then green and then blue progressively, i have some code worked up but am willing to work from scratch again, im working with the lm324 op-amp and an arduino w/328

Question by redd.the.cat   |  last reply


Lm 324 amplifier?

Hello i am trying to build a Lm324 Stereo preamp to go into my 100w tube amp, and i cannot find any schematics on 324's. My idea was to have each channel occupy its own side of the chip, and having a switch to switch between 1 and 2 amp stages. please help thank you.

Question by ski4jesus   |  last reply


linear regulator design, darlington, 5V dropout @ 2.5A !? Answered

The question says it all, really. I built up a linear power supply shown below. My unregulated 12V supply can fall as low as 14.7V @ ~ 2-3 A but if I end up being unable to go higher than 9.5V at 3A. Because I'm driving a motor as a load, the current drawn is very dirty. At 10V I see small dips that correlate to dips in the supply voltage when it goes just under 15V. So what can I do to help alleviate this, as I was under the impression that I would see a absolute maximum of 3V of dropout, not a whopping 5V. (p.s. the maximum gate current into the S8050 is 10mA, but currently set to 6.77mA w/ a 10 ohm resistor) p.p.s: MY design uses an LM324, which is really not the best, as it's slow and cannot sink much current. To alleviate the first issue I simply added current mirrors to aid the op amp in sinking current in a simalar fashion as a current source used for an open collector outputs. What op amp should I use instead for better performance? I suspect the LM324 due to it's low slew rate and low GBP may cause poor high frequency rejection (esp. if I choose to use a switching pre-reg) and poor high frequency load regulation (causes poor transient response on the output) Op amps I can choose from: LM324; // slow, from my testing, this one has inputs that work to ground :D LM224; // ditto, but in a weird package LM386; // slow, but from my testing, this one also has inputs that work to ground. LM741; // ancient relics of the past, not rail to rail by any means, sucks IMO. UA1458TC // ancient relics of the past, I don't have much knowledge of them. Inputs do not work to ground. LM318H; // its in a fancy metal case :D TL072CP; // JFET inputs, but I think the output current is limited and the output can't go below the noninverting input. TL2072AC; OP37; // These things can't even give a stable output by themselves! OP27; // ditto LT1007; // have not messed with it much LT1167;  LT1191; LT1363; CRAZY fast, 1000V/uS!!! Maybe too fast... LT1360; LT1112;

Question by -max-   |  last reply


Op amps? Which one is best?

I have a couple op amps collected over a couple years, and I am working on a design for a linear power supply, but have stability issues, and a "down to -V" common mode input voltage for op amps is a difficult parameter to find. Constraints: * Inputs must work down to as close to the negative supply rail as possible  * needs to be stable when used in a feedback loop for a linear power supply design * low noise / offset / blah blah good good goodies?? Hopefully? I'm actively testing these in a basic comparator circuit to see how far I can get the inputs to the -vee (or ground) before the op amp stops working as intended.I have tested the LM324, LM386, UA1458TC, LM741, and a few of the LT one's. Only the first 2 work well on a single supply w/ the inputs near ground or Vee LM324; // slow LM224; // ditto, but in weird thicc package LM386; // slow LM741; // ancient relics of the past, not rail to rail by any means, sucks IMO. UA1458TC // ancient relics of the past, not rail to rail by any means, sucks IMO. LM318H; // it's in a fancy metal case :D TL072CP; // JFET inputs, limited output current and the output can't go below the noninverting input. TL2072AC; // ditto. OP37; // These things aren't even that fast and can't work at unity gain. OP27; // ditto LT1007; LT1167; LT1191; LT1363; CRAZY fast, 1000V/uS!!! Maybe too fast... LT1360; LT1112;

Question by -max-   |  last reply


Can someone make a breadboard layout for this schematic? Answered

I already have a pulse detector module.. simple with LED and photodector.. It has 3 pins: VCC, GND and one ouput(from photodetector) as signal.. I want to amplify the signal using op amp LM324 i have the following resistors available: 10Ω、22Ω、47Ω、100Ω、150Ω、200Ω、220Ω、270Ω、330Ω、 470Ω、510Ω、680Ω、1KΩ、2KΩ、2.2KΩ、3.3KΩ、4.7KΩ、 5.1KΩ、6.8KΩ、10KΩ、20KΩ、47KΩ、51KΩ、68KΩ、100KΩ、 220KΩ、300KΩ、470KΩ、680KΩ、1M and following capacitors 50V 2.2UF 100V 10UF 50V 10UF 16V 100UF 16V 47UF 25V 33UF 50V 1UF 16V 220UF 50V 0.22UF 50V 4.7UF 50V 0.47UF 25V 22UF

Question by Rahul27   |  last reply


Neotech NT7086 display and arduino?

I found a couple of these older looking dot matrix LCDs in some electronic logbooks that didnt work. it was a 14 pin connector, so i figured why not try it out. i found the pinout of each pin using the chips that were on board, but i don`t know where to go from here, or if i should even bother. the display was made by or for hantronix, and they have a touch layer that could be used as well. each display has 7 of the NT7086PQ chips on it, a 74HC74D, a 74HC40103D, and an LM324. it was originally connected via a flat flex cable, but it had a convenient place for headers to plug it into a breadboard. the 74HC40103D is an 8-bit synchronous binary down counter: http://www.nxp.com/documents/data_sheet/74HC40103.pdf the 74HC74D is a Dual D-type flip-flop: http://www.mouser.com/ds/2/302/74HC_HCT74-225071.pdf the Neotech chips are LCD display drivers: http://www.crystalfontz.com/controllers/NT7086.pdf upon inspecting the physical properties of the display I can see there are the rubber/carbon edge contacts on two sides and a ribbon on one end. The pinout i figured out is: 14 is GND 13 is base on SOT23 transistor     (connected to 12 on parent board) 12 collector on a SOT23 transistor 11 gets pulled low at some point (pulled low on parent board) 10 is power 9 is cl2          (unactive high?) (on one set of neotech chips, assuming the edge contact drivers) 8 Clock input (74HC40103D) 7 does nothing 6 is d4 on one chip? 5 is display off  (active low) 4 is d4 3 is d3 2 is d2 1 is d1 So i would appreciate any input people have. I would ideally like to drive this using an arduino/atmega, and although i have not read the neotech datasheet to much depth it would appear to work similar to the popular parallel displays, but maybe with different syntaxes. so is this a possible thing, or is it a fruitless endeavor? thanks in advance.

Question by zack247   |  last reply