But the issue kept bothering me and so I finally decided to think about it. Communications Equipment, Computers and Peripherals. One option would be a TL or LMV, but that’s just one of an almost infinite number of possibilities. And then a “simplified” discovercircuits, call it “B”: This therefore is equivalent to the LM like putting a bigger resistor across its pins.

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Well information of constant current LED driver. I am designing a light source for my company. The only weakness is current swings due lex power supply changes. Putting these in parallel is dangerous as a small change in the voltage drop over one of the LED strings as they age will cause a divergence of the voltage drop across each parallel chain.

You probably can’t buy such resistor and I am not sure if circuit based on such resistor would be stable enough, but definitely there is no problem with “bulky” resistor and big power loss.

I’d like to measure the voltage drop and light an LED really an optoisolator when it exceeds a threshold. Thanks for sharing the information about constant current LED driver. The data sheet eld the CL2 is at: It belongs in the question. So what you do is connect R2 directly between L and PE terminals.


You have 5 series strings of 5 LEDs.

Even if you need current 1A, it is 1×0. If it’s less than that it may or may not be working there is no minimum voltage below which is it is guaranteed to not work.

Constant Current Circuits with the LM334

Can R3 be replaced with an opto-isolator diode and series resistor? So without doing any math, you lm34 see that current going through the LED wil have to leed space” through the resistor. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. AWS IoT Core is a managed cloud platform that lets connected devices easily and securely interact with cloud applications and other devices.

See LM Spec sheet.

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Furthermore, I think it’s rather crazy that you allow such high ground impedance 10k. But I guess transistor betas used to vary pretty widely within the same part due to small fabrication differences I am not sure how accurate they are nowadays My goal is to make an alarm of sorts when that impedance exceeds a threshold, and the way I want to do that is to detect when ledd is in current limiting mode.


Computers and Peripherals Data Center. When the 1 mA of current is reached, it should begin to increase its resistance, thus increasing the voltage drop across it.

Making a Constant lighting circuits for DC loco headlights

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You actually end up with a stable situation. With a Vcc of volts, we drop 0. However you are right it is usable as a current regulator check the spec.

So which is which? Communications Equipment, Computers and Peripherals. Experiment with the number of diodes and type of LEDs and 1.

Other way, your post is quite interesting. Andrew Stone June 29, at One option would be a TL or LMV, but that’s just one of an almost lfd number of possibilities. These strings are in parallel.