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- Опубликовано: 2 июл 2024
- Welcome to a new voltlog, today we are building a very simple constant current regulator based on the LM338 linear regulator.
Joe Smith testing fake SIBA fuses
• SIBA branded UXCELL Mu...
Welectron german distributor of test equipment and genuine fuses with good prices
voltlog.com/y/r0493
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www.voltlog.com/voltlog-128-lm... 
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This is actually very useful for quick LED driver or other CC circuits, but as it has to dissipate power across it and the resistor, a switching alternative would be ideal for every case!
How do you calculate the output voltage?
What IR temp gun are you using? Do you plan a review of a good termal imaging gun or camera ?any advise is welcome .
I am using just a generic ebay IR temp gun, nothing special. I would like to get a thermal camera because it's useful in the lab but the price is quite high. I might get a FLIR one which is the most accessible option but that one has plenty of reviews already.
Tx for info voltlog Flir is completely out of my price range. I will buy a G 320.
what is the cost of this camera?
g320 is a cheap thermal gun Flir one $230 +
Oh come on, I smiled at the DaveCAD Enterprise Edition.
I suggest the you go just a little further and program an Attiny (or what have you) to put out a scope trigger and a second output to actuate the relay for better reliability.
thank you :-)
2:25 but why not just putting a peace of wire with that resistance ?
LM338 is very good Constant Current Regulator, but how to control it using arduino? Since the resistor must be power resistor? Also power resistors are very expensive and they are coarse in adjusting the precise current is not possible. The resistor must be low value almost impossible to get.
So any way to make this adjustment digital?
I think in datasheet there is a way to use stack multiple LM338 for 10A etc.
You can stack multiple LM338 for increasing the current output but making it digitally adjustable is not easy. This regulator is just not designed for something like that. The solution I showed is good for a few use case scenarios where you need a fixed/stable current for a limited amount of time, if you want to use it longer, power dissipation is going to be a problem.
Do you know digital alternative, with LM338 linear like current adjusment?
And the digital controlled alternative with LM338 linear like current adjustment, NO PWM please is?
John Coops says "No. And if I did, I wouldn't waste my time to tell you." Wow. Don't know what your problem is but a simple "no" would have sufficed. You already "wasted" your time with 3 longer replies to juliusvalentinas so I am confused how it all of a sudden would now be a waste to tell him.
OK, O got it. There is no way to drive LM338 by arduino. But don't know yourself that all those CC LED controllers are actually PWM crap. How else would they stay cool? I even inquired a professional DMX LED driver manufacturer about this, and they do have fancy controls. Their driver drives LEDS using PWM.
I need to build non flicker linear LED CC driver with arduino controll, could be standalone for all I care. I will drive RGBW led. Thank you.
I think you would have a better and more flexible setup if you used an electronic load instead of a resistor for constant current.
Something like this ruclips.net/video/hgrvJ2b2xfg/видео.html
That way you are setup to do other currents and fuses by adjusting a knob and using a 12V SLA battery as your source.
If you come across good fuses that are in spec and cheap, please put a link here. I need some, but I can find are garbage.
Here is a link voltlog.com/y/r0493 to Welectron, a german distributor of test equipment and genuine fuses with good prices. They get their fuses directly from Brymen. They also provided me with free samples for the next video where I compare genuine vs ebay fuses.
I will check it out. Thanks.
For consumers here in the Netherlands you can go to conrad.nl (conrad.de for the germans), it is far from perfect but they do carry real Bussmann fuses. ( The "real" LM338 costs 2.15 Euro @ Conrad).
Wow, they charge you quite heavily in the NL! 338 at Conrad/Austria is €1,50 (TI). And yes, they are far from perfect but it's the last remaining store in my hometown. A good source for Europe is tme.eu (at least I have made good experiences there). Bought a Brymen DMM there and quite some discrete parts, good source for caps too when re-capping vintage/audio-gear.
Digikey sells the LM388 for $2.10 USD each or $18.89 USD for 10. Mouser.com sells them for 10 cents cheaper.
So when they are priced 10 for $1.00, I know they are fake without having to go through the trouble of buying and disputing for a refund.
I like the LM338 it is just $1
Where? All I've seen are fakes sold by AliExpress and Banggood!
On ebay
Link? Have you pushed them to 5 Amps?
Most of the fakes can do 1 Amp with no problems!
Those sold on ebay, shipped from China at these low prices are fakes. Stick with the reputable distributors when buying parts like these. I got the ones in the video from TexasInstruments as free samples so they are 100% real.