LM339 Quad Voltage Comparator
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- Опубликовано: 5 авг 2024
- A brief demo of a recycled LM339 quad voltage comparator IC.
Off-camera, we removed a National Semiconductor LM339 quad voltage comparator IC from a scrap PCB, and mounted it on an SOIC-8 to DIP converter board so that we could plug it into our solderless breadboard. To verify the functionality of the IC, we designed it into a simple LED “bargraph” display circuit, which we demonstrate in this video. The video also contains a short rant lamenting the demise of the dual-inline DIP IC package, a staple of the maker/hobbyist/student/hacker/breadboarder/experimenter communities for the past fifty years.
Network XIII: Electronics projects, demos, builds and teardowns for hobbyists and makers. All are welcome. 
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FANTASTIC DEMONSTRATION ! MY UPS HAS GOT LM339 QTY=3PCS , THANK YOU FOR HIGHLIGHTING !
Surprisingly great video for such a small channel! I just wanted to learn about this IC I encountered in a device in repairing and this was super helpful. Thanks!
Thank you for your kind comments, this is one of my most viewed videos.
nice video, thanks
Thank you for watching, I’m glad that you enjoyed it.
what the responce of lm 339 if it stops comparing .because my lm 339 has not been has not been working nd all the leds is blinking
Im going to make led vu mitter with this.... thanks 👍
how to adjust it to make the same of what you have done in the video but with battery 3.7 to 4.2 ,, i want to light 4 leds between these two values (3.7-4.2) what is the resistors value to use ??
If you are referring to the resistors that are in series with each LED, try reducing them from 1K to 560 ohms, this should give you approximately the same LED current with your reduced supply voltage.
If you plan to use this from the same battery you need a constant 4.2v reference voltage supplied to voltage ladder. In other words you will need a boost converter of some sort. Of course I am thinking that you plan to make similar circuit with using comparator ic. If you plan to use just resistors it would be hard to adjust and you may have to use bjt transistors for each voltage level and even then it wont be as precise toggling of leds. On the other hand you may not use voltage booster and reference for this.
jimmy .ray ruclips.net/video/c_9ZD2t8LSo/видео.html This video may be helpful.
how do you know that in the first comparator its only one volt and so on
The reference voltages for each stage are set by the voltage divider.
What if you wanted to light up only one LED at a time, depending on the voltage?
There are probably several viable ways, one may be to decode the four comparator outputs with some combinational logic.
Or just use LM3914 in Dot Mode.
👍👍
Can i put a pwm signao as one of the inputs? ("Digital" potentiometer)
Lego Mini Movie Productions Maybe if you filtered it with a capacitor (turned it back into an analog signal)
Great idea👍
My company upgrading all hardware using on telecomunication, soo they scrap all of evrything.
I collected some of PCBA, i found soo much IC LM339, its bring me here
I also see IC LM 348 series, i need to know about it.
Thanks for the lesson
Thank you for your comment, I’m glad that you enjoyed the video.
Hi .maybe for smd you can use micro grabers then connect to board?
I have a few sets of those someplace for wide and narrow SO packages, good suggestion
Hello.. nice video. i have a question. when we connect this to battery and over time, the nominal voltage reduces, when that happens the reference voltage also reduces right. so will it work properly??
Sujin Kesavan Yes, if you use a battery for a supply, the reference voltage will decrease as the supply voltage drops. This circuit is mainly for demonstration, there are better ways to implement it that will make it more immune to supply variation.
@@NetworkXIII ruclips.net/video/c_9ZD2t8LSo/видео.html
Can you look into this schematics. It is same as you and it is powered from the same battery which is to be indicated. Can you please explain the ckt diagram for me .because I couldn't able to understand the working
Sujin Kesavan This circuit uses the forward drop of the green LED as a voltage reference.
bought 10 lm339 last week from mouser no problems, and they had any other chip you need in a DIP.
It has been a few years now, so I don’t recall exactly what I said in the video, but 300 mil DIP is no longer a preferred package for new designs. Its great that you can still find old legacy parts like LM339 in DIP, but they’re not going into your new iPhone.
Im just old school and you count not give me anything apple.@@NetworkXIII
I got 10 PC's DIL packages of LM339 on eBay for only 1 € (from china)
DJLinux007 i bought 5 pcs for 2.50$ including shipping but from germany (i'm living there and need the ic's not in 4 weeks but now XD)
why you stop doing movies?
Nice vídeo 🙃
Give me like
krizz rojas Thank you