!!

Welcome to our Forum, extension and content sharing platform of Electrical Test and Measurement Product Reviews Blog.

 
Registration this is Free, we accept contributors of 17 years old and above. We do not accept registration with Gmail

Active since 7 June 2012  


Copyright Notice: Entire ITTSB.EU content & images they are copyright protected. - Forum search engine disabled to Guests - No need of you using Adblock software.

Author Topic: Damaged LM2596S IC ? No problem, next substitute the LM2575T ADJ  (Read 470 times)

0 Members and 1 Guest are viewing this topic.

Online Kiriakos GR

  • Administrator
  • Hero Member
  • *****
  • Join Date: May 2012
  • Location: Greece
  • Posts: 2223
  • Country: gr
    • ittsb.eu
  • job title: Industrial Maintenance Electrician
Few years back I did purchase one LM2596S the supposed be the better version, the one that can do also constant current.

The damn thing blow up right away and I was unable to explore it.
One month ago within an ancient flatbed scanner, I did discover on it PCB one LM2575T ADJ (TO-220), and I did waste my time so to transplant this IC over a PCB designed for DDPAK/TO-263.

Large nice heat sink installed (patent pending), and I thought that now I will get much more juice instead of the poorly cooled version.
No and no, and no gain, at any combination of 10.8 Watt output, the LM2575 get at max of 45 Celsius (because of inadequate cooling), but it does not deliver even a drop of further energy.

My no-name PCB has also one LM358, this has two gates, the one for the Power OK LED this is damaged, and the 100K pot does not help either in any setting while this is working.

-----------------------------------------------------------------------------------------------------
The company that added the LM2575 at their flatbed scanner, it was added for additional DCV stability in case that external DC power block (power supply) this facing very unstable ACV input (old classic transformer with DC rectifiers).
These wise electronic engineers they did not thought to risk the fate of their product by saturating (due overload) this low cost IC.
Instead they use only the smart design of DCV stabilizer by using only a fraction of this 10.8W electrical specification. 

----------------------------------------------------------------------------------------------------
Below are photographs of my freshly revived LM2575 CC / CV. :)
I did connect as power source, one switching PSU 22.5V 0.8A (very common as ADSL router power block).
And here are also electrical conversion examples of how far you can go with 10.8 Watt. 
     

Li-Ion 4.200 V x 5 cells = 21 V / 0.514 A = 10.8W
Li-Ion 4.200 V x 4 cells = 16.8 V / 0.642 A = 10.8W
Li-Ion 4.200 V x 2 cells = 8.4 V / 1.285 A = 10.8W
Li-ion 4.200V x 2.570 A = 10.8W

12V Motorcycle battery 14.500 V x 0.744 A = 10.8W
(13.500 V x 0.800 A = 10.8W)
6V Motorcycle battery 7.250 V x 1.480 A = 10.8W

-----------------------------------------------------------------------------------------------------
LM2575T  / 52 kHz / 1A
LM2596  / 150 kHz / 3A
Latest 2023 model LMR51430 4.5 to 36-V, 3-A, 500-kHz
WWW.ITTSB.EU   Industrial Test Tools Scoreboard  (Product Reviews Blog) / Editor in Chief.
The content of this Web site is copyright protected

Offline overvolt

  • Industrial installer Electrician
  • Global Moderator
  • Full Member
  • *****
  • Join Date: May 2012
  • Posts: 101
  • Country: gr
Re: Damaged LM2596S IC ? No problem, next substitute the LM2575T ADJ
« Reply #1 on: February 07, 2024, 12:34:05 AM »
Another indoor technological success  :)

Basically even 1A of current this is good enough for any battery charger application. 


Online Kiriakos GR

  • Administrator
  • Hero Member
  • *****
  • Join Date: May 2012
  • Location: Greece
  • Posts: 2223
  • Country: gr
    • ittsb.eu
  • job title: Industrial Maintenance Electrician
Re: Damaged LM2596S IC ? No problem, next substitute the LM2575T ADJ
« Reply #2 on: February 07, 2024, 02:57:58 PM »
I did complete 48 hours of circuit testing, by this serving as Ni-CAD charger.

It works and it reliability it is now tested.  ;)   
WWW.ITTSB.EU   Industrial Test Tools Scoreboard  (Product Reviews Blog) / Editor in Chief.
The content of this Web site is copyright protected

 

ITTSB.EU Blog

General Data Protection Regulation GDPR ITTSB.EU Home Page Reward us by a Donation - Sponsorship TsDMMViewer Data Logger for FLUKE 884xA

ITTSB Blog - Sponsors

protosnet.com - Internet solutions FLUKE benchtop DMM Repair Services

Recommended Links

Hellenic Accreditation System E.SY.D. Portal of city Volos - Greece Clean Up and Customize Facebook Firefox Backup Tool 32bit / 64 bit Winaero Tweaker = Win7 Fonts size fix