I think this is a buck converter, but I'm not entirely sure.

Hi Jake,

That is a voltage regulator, also known as a DC-DC converter or a Buck converter when it uses an inductor and switching and steps down the voltage.

You could confirm by examining the part code on the integrated circuit, and obtain the datasheet for the part online. It is extremely likely to be MC34063 (or similar) because that is common in low-cost USB car chargers (and from the photo, the pinout looks about right for that).

Thanks so much! I'm assuming the input voltage would be 12v, yes? Also, is there anyway i can change the output voltage? I'd like to lower it to around 4.7 volts.

Hi Jake,

It will not function to produce a 5V output if you do that. In the datasheet, there is a circuit diagram for step-up mode, which is different from step-down mode. It would be awkward to try to modify to step-up mode without a new circuit board or cutting tracks etc. However, step-up devices are available from ebay etc at low cost, e.g. this one (I've not tried it, so cannot be sure it is any good, but I don't see a reason why it wouldn't work):

8W Boost step up Adjustable Regulator Converter 5V-12V Power Supply Module | eBay

I'm not making it go to step up mode, it runs on 12v and I want to lower the output from 5v to 4.7v although I now know that I'm going to have to find someone to replace the surface mount resistors for me.

I think it's the output he want's to lower to 4.7V not the input voltage. But yes, there are limits to how the input/output can be altered without needing to change the topology of the circuit and/or a number of other components which would get difficult to achieve on a board like this.

Hi Rachael,

Ohh I see. I'm sorry Jake, please ignore my comment!

its fine. I admit I could have worded it better.

Jake Linville wrote:

 

...although I now know that I'm going to have to find someone to replace the surface mount resistors for me.

Or use it as an excuse to invest in a decent soldering station! You don't have to spend huge amounts to get something adequate for starting out and it'll prove to be exceedingly useful time and time again if you continue to pursue electronics further

Hi Jake,

You didn't specify the reason for 4.7V, but if you're happy with "about 4.7V" then you could put a diode in series with the output. The output won't be accurate any more, but will be lower than 5V slightly (could vary to 4V or lower). For any accuracy you need to take the approach Rachael mentions with the resistors,but needs the steps mentioned (soldering capability, resistors purchased). If you're interested in this as a hobby, see this URL for lots of information: I Want to Do Electronics!  Where do I start?

well, the reason is I'm actually trying to make an adapter for my 3ds. There was an old gameboy advance charger that hooked into both the wall or a cigarette lighter. I plan on making one of these that is fine tuned for the 3ds, as it is VERY cheaply made and will break at a little over 5 volts (it normally wants 4.6)

I actually do have a soldering station. I picked it up for that project I mentioned, and have been making small circuits for fun, but because I'm a broke 15 year old, the only parts I have come from broken radios and computers. although I do have plenty of resistors.

shabaz wrote:

 

You didn't specify the reason for 4.7V, but if you're happy with "about 4.7V" then you could put a diode in series with the output.

Yes if you only need approximately 4.7V then this is a good idea. If you use a schottky diode then the Vf of the diode should be low enough that you'll be around the 4.5-4.7V range depending on the exact device chosen and the current being drawn.

shabaz wrote:

 

If you're interested in this as a hobby, see this URL for lots of information: I Want to Do Electronics! Where do I start?

I'll second this, and its author (jw0752 has done a lot of other great blogs which are worth reading if you're interested.

shabaz wrote:

 

You didn't specify the reason for 4.7V, but if you're happy with "about 4.7V" then you could put a diode in series with the output.

Yes if you only need approximately 4.7V then this is a good idea. If you use a schottky diode then the Vf of the diode should be low enough that you'll be around the 4.5-4.7V range depending on the exact device chosen and the current being drawn.

shabaz wrote:

 

If you're interested in this as a hobby, see this URL for lots of information: I Want to Do Electronics! Where do I start?

I'll second this, and its author (jw0752 has done a lot of other great blogs which are worth reading if you're interested.