Hello there!
I am using this DC-DC Buck Converter Step Down Module LM2596 : https://robu.in/product/lm2596s-dc-dc-buck-converter-power-supply/
Facing an issue with 5 volt buck converter when switch on the circuit from Main Power supply as shown in block diagram.
When the circuit is turn ON by battery then it works fine but over a period of time when it gets on from Main AC supply 5 volt buck converter is damage and as a result all the 5 volt connection remain off.
Your topic was MOVED to its current forum category which is more appropriate than the original as it has nothing to do with Installation and Troubleshooting of the IDE
Hi, @dhruvi_s
What is the input voltage to the DC-DC converter when it is on battery? (Measure it please)
What is the input voltage to the DC-DC converter when it is on Mains? (Measure it please)
I have used those converters, from Aliexpress and reputable vendors and they are not very reliable when near their rated specs, usually a 50% success rate.
In particular the inductor needs to have a heavier current carrying capacity, it gets hot.
The heatsinking on the 2956 is just enough most of the time.
They have been built for a very cheap price and unfortunately you get what you pay for.
Tom.. 
What is connected to the microcontroller? Post links to "Technical" information on the hardware devices including the converters. Your drawing shows no interface between the microcontroller and the 24V system other then they share a mains power switch.
Thank you for your reply.
I have checked input voltage on battery and main it is as per system requirement. In buck, Input 24 v on Mains and output 12V.
Thank you for your reply.
Diagram.pdf (181.5 KB)
I have used MQ7 CO sensor in device. When it is connected , Buck converter discharging is very fast & when I remove MQ7 sensor buck turns off slowly. Is there any possibility that buck converter damage isssue is related to this sensor or temperature afftect it ?
Hi,
Can you post a circuit diagram, showing ALL wiring , component names and pin labels?
In jpg format posted in the post.
Your block diagram is not showing the information we need.
Do you know how much current the MQ7 sensor consumes, it has 4 connections, please show all four connections and where they go.
Thanks.. Tom..
PS. Can you please post image(s) of your project so we can see your component layout?
Posting the schematic sounds like a good idea. Per the 2956 datasheet it has a thermal limit and the fact that it works ok on a battery suggest it is Not a thermal issue. The datasheet warns of input transient protection by way of a properly selected input capacitor. It would be a good idea to use an oscilloscope to see whats going on here. Also layout can be important as well. Best wishes.
Thank you for your reply.
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.
