Microscopic Voltage Regulators - How in the world do you people solder these!

Thread Starter

sirchuck

Joined Feb 14, 2016
131
Have a quick look at this part:
https://www.amazon.com/Regulator-DROK-Converter-Step-Down-Transformer/dp/B0758ZTS61/ref=sr_1_1_sspa?crid=2UXXDSPQRLXP8&keywords=5v+fixed+buck+converter&qid=1552351337&s=gateway&sprefix=5v+fixed,aps,150&sr=8-1-spons&psc=1&smid=AFHAE9RJVUMB

My project needs a 5v and a 3.3v output from a 9v battery. So naturally, to a novice like myself, this made me overjoyed with happiness.

It looks to me like you simply attach the 9v + and - to the bottom IN+ and GND ports. Then you attach the 5v + output to the solder point on the back of the board marked 5v and then to the common GND port at the bottom of the IC. Same for the 3.3v.

The board is so tiny that attempting to solder my 30 Gague wire up was about impossible as the wire was almost wider than the solder ports.

Once I got finished hooking everything up as I explained above, my output readings were wrong, 2v instead of 5v and so on.

At the top of the IC it shows you can cut something off, but I don't know why you would need to.

My question is, is this chip not meant to be soldered normally? is it meant to plug into something maybe? If so what do I ask for so I can buy the thing that you push this card into?

The entire IC is about the size of your fingernail.

I have 4 more as they come in a 5pack, so hopefully, I can get some use out of them in some way.

As always - thanks for your input.
 

Papabravo

Joined Feb 24, 2006
14,386
Ah the tiny bord in the pictures, I thought that's what is called an IC. :D
IC is an abbreviation for Integrated Circuit. The IC on the board is the little black plastic thing that looks like a bug, with 8 legs, 4 on each side. The package is referred to as an SOIC (Small Outline Integrated Circuit). Here are the mechanical specs of an SOIC-8 from ON semiconductor.

https://www.onsemi.com/pub/Collateral/751-07.PDF
 
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Thread Starter

sirchuck

Joined Feb 14, 2016
131
IC is an abbreviation for Integrated Circuit. The IC on the board is the little black plastic thing that looks like a bug, with 8 legs, 4 on each side. The package is referred to as an SOIC (Small Outline Integrated Circuit). Here are the mechanical specs of ans SOIC-8 from ON semiconductor.

https://www.onsemi.com/pub/Collateral/751-07.PDF
Thanks for the lesson. :) Do you know the answer to my original question though? I'm trying to figure out if that board is supposed to be plugged into some sort of female socket, or if I'm really supposed to solder it?
 

BR-549

Joined Sep 22, 2013
4,938
You have to solder your connections. Make sure that your 9 volt supply has enough capacity.

I am not 100% sure......but it appears you have choice of outputs. It looks like it comes set up for adjustable output mode...set by pot.

If you want a fixed output........cut that strip at the top, then solder the selected voltage tab.

That selected voltage will appear at output terminal. Be mindful of current for your wire size.
 
Note that there are no holes to support the PCB which basically means support along the edge or as @Papabravo had to say, use headers and female sockets.

lately the PCB industry has turned metric. Breadboards are 0.1" on center typically and they are still being used. Companies like http://www.proto-advantage.com/store/ make adapters for IC's to this standard 0.1" pitch.

It also turns out to be 2.54 mm. You also have 1.27mm and 5.08mm as pitches. leftover from the English system.

Since stuff is metric you will find 1.3mm, 1 mm. 1.5 mm etc. Convenient numbers in the metric system.

So, you really need male headers and a female socket. Some of these are breakable. So a 44 pin x 1 header can be cut into a 4 pin header.

Edit: Fixed link:
 
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Yaakov

Joined Jan 27, 2019
1,612
The board is so tiny that attempting to solder my 30 Gague wire up was about impossible as the wire was almost wider than the solder ports.

My question is, is this chip not meant to be soldered normally? is it meant to plug into something maybe? If so what do I ask for so I can buy the thing that you push this card into?

As always - thanks for your input.
There are several things that you need to successfully solder small parts like this.

You need the right iron.
You need the right solder.
You need magnification.
You need good light.
You need to know how.

First the equipment is very important. It is easy to make bad joints or overheat things without it. So, tell me, what sort of soldering iron are you using? What sort of tip?

Whatever the soldering iron, the tip needs to be bright and clean. No pitting, no burnt flux. This is very important. The tip must easily accept solder, and must be able to transfer heat efficiently. So, do you regular clean and maintain your tip?

Second, you need the right solder. It should be 63/37 lead solder, rosin core, and quite thin. I use .015 but .031 is workable if more difficult for a beginner. It’s worth buying the good stuff, like Kester. So, what are you using for solder?

Third, you have to be able to clearly see what you are doing. Even if your vision is good, particularly when you are a beginner, you need to see exactly what is happening. An expert can imagine quite a bit about what is there that they can’t see, and what the solder is doing to the invisible bits. Even then, magnification helps a lot. For the beginner it is vital. So, do you have a magnifier?

Fourth, lighting ties in with the third thing. You need to have the right sort of lighting. It needs to be bright, without too many strong shadows. Solder is very specula and many boards are dark, this makes seeing what is happening a challenge, do you have good task lighting?

Fifth, you need to know what steps to take to make things both easier and better. It’s not rocket science, but you need to know. Many boards you will see today do not have lead solder on them, this is a problem in that lead free solder is a pain to work with. You can usually tell the lead free stuff because it is dull and makes ugly joints, not like the shiny, pretty ones you are going to make. So, the first step is to carefully add a small amount of your nice lead based solder to the pads. Not a lot, just enough that the existing solder will alloy with it and the melting point will go down.

Remember, always place the iron on the lead and pad and add solder to the pad, do not add solder to the iron on or off the pad. This will burn the flux and you will fail.

Next you need to tin the leads before you try to solder them to the board. If you do this right, they will fit fine, and it will take little heat to make the solder joint. Take your time and do this right.

Don’t use too much solder. More solder isn’t a better joint, the right amount of solder provides the optimal electrical and mechanical connection, and it isn’t a lot. When you are done, you should have a little volcano shaped pile of solder around the lead and to the pad. This is a meniscus formed by the liquid solder, and shows you’ve got just enough. There shouldn’t be a blob or a lump, and you shouldn’t be able to see the hole or the pad just around the lead.

I would encourage you to find some good soldering videos on YouTube so you can see the process and get more of a feel. But you need the right tools and materials as much as you need the knowledge and skill. Soldering even tiny things is not very hard if you do have the right tools, but if you don’t, it’s a nightmare.

Good luck!
 

pmd34

Joined Feb 22, 2014
518
Hi sirchuck, it looks like the "cut off" point on the board is to disable the adjustable (default) option on the board so you can then put in a solder bridge to select the voltage resistor you want to use.

The board is meant to have wires soldered into it I guess, though you may find it has a standard 2.54mm spacing so you can use it with these
https://www.aliexpress.com/item/20pcs-40-Pin-1x40-2-54mm-Single-Row-Male-Breakable-Pin-Header-Connector-Strip/32895109708.html?spm=2114.search0604.3.16.65693187o1ZdfZ&s=p&ws_ab_test=searchweb0_0,searchweb201602_7_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536_10902,searchweb201603_56,ppcSwitch_0&algo_expid=72ff2b51-281d-44b4-96ac-03d44dedced7-2&algo_pvid=72ff2b51-281d-44b4-96ac-03d44dedced7
sort of "header" pins for mounting into another circuit board, or similar spacing plug and sockets.
 

Yaakov

Joined Jan 27, 2019
1,612
Hi sirchuck, it looks like the "cut off" point on the board is to disable the adjustable (default) option on the board so you can then put in a solder bridge to select the voltage resistor you want to use.

The board is meant to have wires soldered into it I guess, though you may find it has a standard 2.54mm spacing so you can use it with these
https://www.aliexpress.com/item/20pcs-40-Pin-1x40-2-54mm-Single-Row-Male-Breakable-Pin-Header-Connector-Strip/32895109708.html?spm=2114.search0604.3.16.65693187o1ZdfZ&s=p&ws_ab_test=searchweb0_0,searchweb201602_7_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536_10902,searchweb201603_56,ppcSwitch_0&algo_expid=72ff2b51-281d-44b4-96ac-03d44dedced7-2&algo_pvid=72ff2b51-281d-44b4-96ac-03d44dedced7
sort of "header" pins for mounting into another circuit board, or similar spacing plug and sockets.
That form factor board does use .1” headers, so for a protoboard that would be easier.
(To be clear, that was agreement, though in American Customary Units.)
 

Thread Starter

sirchuck

Joined Feb 14, 2016
131
AlbertHall - huh so that little metal thing is the potentiometer, I thought one had to be soldered on.

Yaakov, yes magnification is key. I really do not have the tools I need for something this small to do well yet. I think my other problem was using wire that was just too thick, even though I thought 30gague was thin. It was wire that has many strands, and I probably squished it flat with my iron which made the wire so wide it was hard to get 5v and 3.3 v connectors soldered on without touching.

pmd34 - Hmmmm, maybe cutting that makes the other named voltages give clean signals. I'll have to try that when I find it again and feel like burning my fingers on the soldering iron again. :) Electronics is fun.
 

BR-549

Joined Sep 22, 2013
4,938
The only solder wire connections are at the edge terminals. Those four terminals on that one short side.

Those labeled solder tabs....are just solder switches.

Only one voltage output per board.
 

Thread Starter

sirchuck

Joined Feb 14, 2016
131
The only solder wire connections are at the edge terminals. Those four terminals on that one short side.

Those labeled solder tabs....are just solder switches.

Only one voltage output per board.
Wait, what?

Do you mean the 12v, 9v, 5v, 3.3v, 2.5v, and 1.8v on the back side do not output those voltages there? Or do you mean that if I solder to the 5v, then I can not also draw from the 3.3v at the same time? Or do you mean whatever is on VO+ is the only output I'm going to get? Does the Enable come in to play here?


71iVp1ZZeYL._SL1500_.jpg
 

Thread Starter

sirchuck

Joined Feb 14, 2016
131
The only solder wire connections are at the edge terminals. Those four terminals on that one short side.

Those labeled solder tabs....are just solder switches.

Only one voltage output per board.
OOOOOh I think I get it now. (Solder Switches) I didn't understand that, but you mean the manufacture probably soldered a bridge like they did in the 5v image above to give me 5v at the VO+. Ok that's making some sense now I think.
 

Yaakov

Joined Jan 27, 2019
1,612
OOOOOh I think I get it now. (Solder Switches) I didn't understand that, but you mean the manufacture probably soldered a bridge like they did in the 5v image above to give me 5v at the VO+. Ok that's making some sense now I think.
The use of scissors to indicate “cut” is very misleading. The instruction means to cut he PCB trace. Which removes the potentiometer used to adjust the output. Then, you select a fixed output by “bridging” one set of the pads corresponding to the voltage of interest.

30GA wire will be just fine for the through hole connections to the board. The pads to select a fixed voltage aren’t intended for wires, as you’ve been told, just a small bridge. And you probably don’t need to bother, just use the adjustable output.
 

Thread Starter

sirchuck

Joined Feb 14, 2016
131
If you turn the top of that potentiometer does it change the voltage at VO?
I assume it would, but I don't have the tool to turn it. I stuck my little screwdriver in it and twisted but nothing changes. I put a 9v on it and am getting a steady 8.76V out of it.

I'm about to try cutting it as the picture shows, I made a 5v solder bridge so I'm hoping I don't cut or break too much.

"The use of scissors to indicate “cut” is very misleading. The instruction means to cut he PCB trace. " - assuming I can tell which line is the trace I think it will work. I soldered the 5v bridge so if I mess up anything higher than that I don't really care.

With the power of the internet, I'll let you know how it goes on the next line...

Well, the scissors image does not mean use actual scissors. I'll have to figure out how to scratch the area to cut the trace maybe.

I wish they used like a different color to draw a line to show exactly what you're supposed to cut. It looks like I'm supposed to cut just a little bit of trace coming off the top of the solder bridge spot for.
 
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