$5 buck driver on ebay

[LaZeRz]

Hey guys, what do you think of this

LM2596 DC Converter Adjustable Power Module Regulator | eBay

Seems like a good driver for some large builds... Not too sure if it will be suitable for LD's but it looks promising.

 

[532 with Envy]

That's a nice little find with some real potential!

If you pick one up, being in Australia, let us know what you find. They may be good for projector builds or like you said larger, perhaps multiple diode builds.

 

[jakeGT]

8-45V? So dual cell builds will only keep it running for a few minutes right? So it would have to be a large build fo sho

 

[Cyparagon]

Here's a 3.2V+ model. It looks the same, though. Soldering will be required to convert it to constant-current, and depending on the Vref of the system, the sense resistor might ruin the efficiency.

 

[piferal]

The problem I see is that it is a voltage regulator, not a adjustable current regulator, if I'm not wrong.

If you want a voltage and adjustable current regulator, look at like this for example, or similar.


http://cgi.ebay.es/DC-Power-Supply-...824?pt=LH_DefaultDomain_2&hash=item3cb6ad07e8


I bought several and they work well.

 

[bobhaha]

The problem I see is that it is a voltage regulator, not a adjustable current regulator, if I'm not wrong.

If you want a voltage and adjustable current regulator, look at like this for example, or similar.


http://cgi.ebay.es/DC-Power-Supply-...824?pt=LH_DefaultDomain_2&hash=item3cb6ad07e8


I bought several and they work well.

Those are nice! I'm gonna pick some of those up for testing.

@OP 22uf caps? That output is gonna be horrible! It won't filter out the ripples at all.

 

[piferal]

Here are the same, but with cables and clamps, and the uncovered components.

These are the ones I've bought

http://cgi.ebay.es/1-35V-DC-25W-Pow...603?pt=LH_DefaultDomain_0&hash=item3cb7107813

 

[LaZeRz]

yeh, well, its probably more suited to LED's or something... lol

Just putting it out there, I was about to go to bed and I couldnt be bothered looking around on ebay anymore. haha

 

[Cyparagon]

@OP 22uf caps? That output is gonna be horrible! It won't filter out the ripples at all.

How do you figure that?

 

[bobhaha]

I read it somewhere... now I can't seem to find it :wtf:

 

[Cyparagon]

The equation I have for filtering of a full-wave rectifier in my notes here is

Vripple = Vp/(2fCR)

Where Vripple is the peak-peak ripple voltage, Vp is the peak input voltage, f is the drive frequency, C is the capacitance, and R is the resistance of the load. This means that for a given voltage, the ripple voltage goes down when you increase either the load resistance, the capacitance, or the frequency. The frequency on these switching drivers is VERY high compared with say the 60Hz from the wall. This means that much lower capacitance is needed to keep the ripple voltage to a minimum.