LM2596 based DC Buck convertor | Circuit Diagram and pinout

what is the purpose of the inductor in the circuit??

Thanks , Good video , i made circuit same as yours but with LM2576 and it works perfectly

I guess watching videos, even as good as yours and others, doesn't ensure success or even an adequate understanding …
I'm trying to find a battery power source to power four strobe light units installed on my PARAMOTOR as we fly in often congested airspace.  Air Force and civilian aircraft like to fly low over the water just off the beach here in Northern Florida just where we'd like to fly.
I purchased supposedly 12v truck led strobe light KIT to attach to my frame.  I finally got a multimeter this week and measured the demo battery pack that comes in the strobe package (allows strobes to work on the store shelves) and – the batteries were providing 19.5 vdc.   

So these are likely the fairly standard 12-24v LED strobe lights sold everywhere.
I have a spare 6S LiPo 50C battery pack that provides 22-25.5 vdc so I figured I use this.  My plan was to wire up the LM2596 to measure the output voltage and adjust the potentiometer to 19-20 vDC output to test the strobe lights.  Input measured 25.1vDC.I put the multimeter leads on the OUT side and made a short piece of twin lead wire connect the IN side and inserted them into the XT60 connector.

BOOM
A firecracker went off and the capacitor was gone. I turned the Multimeter on after I inserted the twin wire, don't know if that caused the overload – no load when connected?

The video said the LM2596 was rated for 30 vDC.  A flying buddy offered that perhaps the 6S LiPo's amperage was too much.

I measured the 6S LiPo and it jumped around but seemed to be between 373 and 420 mA.  It's a new Chinese multimeter and I probably don't know how to use it properly.

The small battery pack seemed to measure between 95 -200 mA when connected and would drop to ZERO when the button was pushed.  Not sure I understand that behavior.  

Any comments you'd care to offer to me.  I have another spare buck to use but need to figure some other combination to power the strobe lights.
"Help me Obiwan …"

What is the voltage capacity of the capacitor?

If it use in negative voltage????

Only useful for low power as the efficiency is not good.

Kindly also explain current

That symbol is for a zener diode. The schottky diode and rectifier diode have different symbols.

SO and Yaaaaaaaaaaaaaaaaaa !!!!!!!!!!!!!!!

A heat sink is desirable.

good video well explained. do you know what happens to the output voltage when the input voltage decrease ??????????
vin = 12v output 5v ( regulated in pot.)
vin = 10v output= ? stays regulated
vin = 9v output = ? " "
vin = 8v output = ?
etc . for example
thanks .

Lm3671 ic detail?

Good

very good explained

What sould i do for high temprature
when using as led driver with 30w cob led it gone high temprature an then burnt-out after 2 minutes. …please tell me something for this. …

Can you please do a follow-up video (or reply here) adding a voltage output limiter (5.1v Zener reference) feedback loop to pin 5 of the 2596 to disable output when the threshold (5.1v) is exceeded. This type of protection would be helpful if only a few components are required.

The value of the inductor is wrong in the drawing. A printing of 330 on the inductor refers to 33uH type. The Schottky diode should be something like an 1N5822/1N5825.
For values meeting your VIN/VOUT/IOUT requirements maybe refer to:
http://www.ti.com/lit/ds/symlink/lm2596.pdf
including tables for various configurations.

Can we use it in 40 w solar panel for 14v

Which schottky diode is?

thank you for your video; I tried this circuit to provide 7.5 volt to my arduino uno. I go from 28 volt DC to get that 7.5 Volt. I found out that the L2596 becomes hot. Can it handle 28 volt ? Is it normal that it becomes hot ?

If i increase the voltage, does it also increase the current or ampere?

The Shottky diode is to make sure no voltage spikes occur as a result of the inability of a current through an inductor to change instantaneously.

Please tell how can i add a comstant current control to a lm2596 buck converter board

This App gonna save lots of time for LM2576/96
https://play.google.com/store/apps/details?id=com.cruxbd.emon.lm257696adjcalculator

What is the value of inductor?

purpose of schottky diode is to remove reverse current in case of inductor load.