LM723 Regulator with Voltages and Maths UEENEEH138A TAFE NSW
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- เผยแพร่เมื่อ 19 ต.ค. 2024
- Notes for this at www.learn.org.au UEENEEH138A. Using the LM723 voltage regulator in a very typical circuit giving voltage (and current) control. All the maths shown to calculate output voltages. In part 2, I'll show how the output voltage folds back to protect the current dissipation of the output transistor. Blue Flames (Instrumental) by Kara Square (c) copyright 2018 Licensed under a Creative Commons Attribution Noncommercial (3.0) license. dig.ccmixter.or... Ft: RobWalkerPoet, Martijn de Boer
Moore, thank you for sharing this excellent explanation with us.... good quality material for understanding the famous LM723.
Ass. POLILO - São Paulo - Brazil
I don't care for the TH-cam like system. This is a 10 thumbs up video! Thank you so much!
Thanks Greg, it explains so much a wide area around the LM723 where i couldn't find all at once on the net.
Greg, thx for taking the time in sharing your observations and analyses of a representative power supply circuit.
I did get different numbers for the OpAmp input voltage with the pot turned all the way down. I used the measured values that you stated and got an expected value of 0.670V. I cannot explain why the measured value was 0.673V which is higher.
A couple of things that the datasheets all omit is: the Error amp input bias current, input bias differential current, input offset voltage and minimum input voltage.
I find the LM723 can't be beat as a power supply core device. I hope they keep making them. I haven't really found a single IC replacement that performs all the functions that the LM723 has built in with the excellent specs that it has.
Again, thx for sharing.
Great video, exactly what I was looking for... Thanks for the dedication! By the way...are those books a shelf holder? lol
Almost fun! thanks for posting.
Thank you so much
Can maybe an external reference be added?
I noticed there is no resistor on base of the transistor. And what is Vs on the TI schematic? 🤔
Hi, if you look at the circuit for the internals of the 723 IC, there is a current limiting resistor which is built in to drive the base of the external transistor. This is a very classic design, and 50 years after being first produced, the 723 is still a versatile chip. I think it's good to about 40 Volts, you'll need to check the data sheet. :)
@@gregmoore7565 Well done sir. Wait, did you say 50yrs old, I had no idea this chip was that old!
If you look at the new design internal schematic you'll see +Vs & -Vs, which I believe is what you are referring to. As you might've guessed that is the positive source voltage and negative source voltage that powers the ICs internal circuitry.
Hope this helps.
One thing I've noticed on the TI drawing is something called Vsense, what pin and what is the value with 14Vdc applied?
Notes for this 723 with full explanation: www.learn.org.au/ueenee-course-pages/ueeneeh138a-fault-complex-power-supplies/psu-week-6/