BuckPucks - buck converters - resistors - and where to get good parts in Germany

Hi!

I have some questions since I am new in the LED-lightsaber game :)

I noticed that the gold standard of voltage regulation are buckpucks.
Since they are a little expensive the alternative are resistors - please correct me if I am wrong.
So why resistors and not buck converters (like this one)? The price is very low (about 2€).
My understanding is that I don't have to worry much about them, they don't waste more energy than resistors and if I switch my battery Pack I don't have to change them (as long as it is in the range of the buck converter).
So what is the downside of buck converter compared to resistors?

The second question is:
Where can I get a buckpuck?
I live in Germany and haven't found any shop that offfers them exept one that charges 25€+shipping for them...
I order the rest of my parts at led-tech.de and conrad.de - do you have better alternatives for me? I would be thankful!

I found these:
No.1
No.2

Will they work like a buckpuck?

Thanks and best wishes,
Voi

You can get pucks here.
Sorry, but we aren't allowed to post where to buy things that TCSS stocks, because this forum is attached to the store.

Ok, thought so but the shiping + tax + toll charge makes ordering to germany pretty expensive...
Any thoughts on the theoretical resistor buckpuck question?

??? If you mean which one's better, then a buckpuck is better...

And this ain't a cheap hobby - I live in Finland and the shipping is more than 40 $ each time.

+1 to that, Africa shipping for me

Ok, thanks for the answers so far!

The remaining question are:
- resistor or buck converters - what are the pros and cons
- would a dc/dc converter like the ones above work fine and replace a buckpuck?

Resistor
+Size
+Price

-Inefficiency (Output voltage goes down with that of the battery, and some of the energy is wasted=> resistor gets warm when in use)


Buckpuck
+Efficiency (Constant voltage and mA)

-Size
-Price



About the converters...
The first one in my opinion would work perfectly, only that then you'd need >5.5v power source.
I don't know about the second one, though.

Ok thanks, I'll try it with a 9V battary.

Don't ever use a 9v battery in a saber. They are only good for low draw applications, like blinking a 5mm LED.
And they won't put out enough immediate current to drive a 3W LED.

oh, ok.. thanks for the warning.