universal usb power supply kit
The challenge is to lay out everything on the PCB.
This becomes more complicated by the need to create a single sided PCB layout so that anyone can build it on a perforated plate/peg plate/breadboard (
We call it a breadboard for this istructural).
If I did a double sided PCB then wiring on such a basic circuit would not be a problem.
Finally, I made some changes to the layout of the component before solving Rev 2.
Rev 1 is laid out and seems to be the easiest way I can arrange it and run traces.
Very little consideration is given to how users will interact with the board.
On Rev 2, I decided that I needed to focus more on how the user would handle it, so I focused the arrangement of parts on placing key items such as terminal blocks, USB connectors, and power switches.
I also think it would be better to put the LED indicator in the middle of the board.
Considering the breadboard layout, I have included a PDF file of the Rev 2 PCB layout without copper padding.
It cost me about $2 to buy a double mini board breadboard from the Radio Shack. 19.
This breadboard is a little bigger than my PCB layout.
Most importantly, the PCB layout line is aligned with the grid of the breadboard.
So you can print the PDF of the PCB layout below and overlay it on the breadboard.
Now put things together.
After printing the layout, reduce it to size and tape it to the side of the board without a copper pad.
Align the bottom right corner of the layout with the bottom right corner of the board.
Keep the board and layout in the light so you can see where the holes are through the paper and arrange everything neatly.
To help make sure the holes are all aligned, remove one of the parts and use it to punch out all the parts holes.
If things don\'t match well then adjust as needed.
In most cases, you will be able to weld the components together, similar to the PCB layout, but you may need to make adjustments in some parts.
We will discuss this in the next steps.
I\'ll break the components down into a couple of steps to help you make sure everything is plugged into the right place and welded together.
If you would like to try etching your own board, I have included the PCB File for Rev 2 below in the Extended Gerber, PDF and Eagle CAD files.
I also include a Fritzing file for the REV 1 board with a simple prototype breadboard layout if you want to do it before putting everything on a PCB or peg board
The finished board is only 40mm x 40mm.
As you can see, there is still a lot of open space on the board.
It can be done smaller for the final PCB production.
I did consider having the resistor mounted at one end to help narrow things down a bit.
But we don\'t want to make things too small, otherwise it\'s hard for amateurs to assemble.
I hope to put the money together in the near future and make a small plate production.
I may go through more changes before this happens.
We will start on the left hand side, all the way up and down.
Resistance Leads need to be bent to the right at the edge of the resistance to fit in the hole.
As needed, refer to the reference diagram above and place the resistance in the specified position.
The resistance in the figure is clearly marked.
Their own resistors are clearly marked in one form or another.
Resistance color codes are used for 22k and 15 k.
The rest have printed values.
With the exception of 6 k, its physical size is larger than others, which makes it easy to pick.
Bend the leads of the resistance so that they don\'t fall off when you flip the board to weld in place.
When using a breadboard like this, I like to use the leader of the component to link the track from one component to another.
So it\'s a good idea to bend your leads to the direction of the nearest assembly they\'ll be linking.
After the resistor is in place, flip the board and weld it in place.
Don\'t worry about soldering the end of the lead into traces until we have all the components in place.
But continue to bend them to where they need to go with your pliers and cut off any access so it doesn\'t get in the way.
Put the capacitor in place now.
The electrolytic capacitor is close to the terminal block area and the ceramic is close to the voltage regulator.
Pay attention to the polarity of the electrolytic capacitor.
The silver stripe on the side of the can is the opposite side ,(
It\'s also one side of the short lead)
If you keep your board oriented in the same way as the reference image and need to be on the right side.
In order to be installed correctly on the board, you need to be fully straight out of the lead.
For LED and diode, it is important to note which lead is anode and which is cathode.
On the LED, one lead is longer than the other, indicating the anode.
So your short lead is the cathode and should be on the right side of the board.
The cathode of the diode displays a white line around one end.
The line should be towards the left side of the board.
Just like before bending the lead in the direction they need to go.
Flip the board and weld the lead in place.
Then collapse the lead and trim as needed.
Now we will put the voltage regulator and switch in the proper position.
Check the reference image and make sure to place the voltage regulator in the correct direction.
You can bend the leaders of the regulator a little, but not enough to use them as tracking.
So as long as they are bent enough, it will remain in place.
The leader of the switch is a little wider than the hole on the bread plate.
So you need to bend it a little and make it fit.
Like the regulator, the lead on the switch is not long enough to be used as a trace, and you may not be able to bend the lead at all to help keep the switch in place.
It is likely that the friction of the lead in the hole will help you catch it.
Flip the board and weld the two components.
It\'s time to put the terminal and USB connector in place.
Make sure that the opening of the terminal block is facing the outside.
The wiring terminals stretch out several plastic legs in front of the lead.
You can choose to clip these holes down or widen the holes on the board with a 1/16 drill bit.
I would suggest expanding these holes as they help to maintain the position of the termination block.
As for the USB connector, you have to do some extra work here.
There are two clips on both sides of the connector.
You need to expand the holes on the board (
Specified as GND on the reference image above)
Use a 5/64 drill bit so that the clip can be stuck on the board.
Like the switch, the junction box and USB connector leads are not long enough to bend and use as traces, but friction should keep the two parts in place until you weld them.
Weld everything in place.
Now, start with a component and start bending the lead for the rest of the time to reach the component they need to connect.
In the absence of leads, you can help your track to start creating a welding bridge between copper pads and assemblies.
It might be a good idea to take some scrap wire and peel it off as a track from one part to the next.
If you don\'t like the look of the welded bridge on the breadboard, then use some wires to go straight from one assembly to the next.
Take a moment and do a tracking at a time.
Just like they always say \"measure twice, cut once.
In this case, check and verify two trace placement and one welding.