quickie pcb production (with bonus nicd battery charger)
This is probably the way we are going.
But if you\'re stuck on a desert island without a laser printer, you still want to find a super
Fast printing circuit? What then? (
OK, to be honest, in order to make a quick and dirty battery, I find it a bit of a hassle to light the eagle etc. Charger circuit. )Here\'s a start-to-finish home-etching-with-Sharpies mini-tutorial.
It is basically \"draw the circuit with sharp edges and then etching\", but gold is in the details.
From blank copper-
Cladding of working prototype: copper cladding and matte knife, cutting itScrubby padding to illuminate it3 (3! )
Types of Sharpie: Ultra-Fine, Fine (Regular), Chisel-Tip (Wide)
An empty plate (
EtchantDrill and bitcomponent rail pen and paper for the development of the circuit layout. We\'re building a constant-
The current battery charger has little fancy sound.
The circuit is simple enough.
Put a resistor (
Or parallel resistor group)
Between the two pins of the LM317T voltage regulator, its output current is equal to 1. 25 V / R ohms.
In fact, the only whistle for this cicruit is to add a bunch of sockets that can achieve variable charging current, which is convenient because I have a bunch of NiCd/NiMH batteries with different capacity, want to charge them.
So first, I searched on Google and then drew the circuit on the paper.
Next, I look up the pins of the LM317 on the datasheet and use the actual-spacing pin-
Just to see how much space I need.
It\'s good to have a mirror-
Image version of the circuit layout to help you open
The copper version you want to make.
If your digital camera is nearby, take your picture and mirror it
Images on your computer
If you mirror by hand, remember to flip all the pins on ICs --to-right. Double-
Check the direction of your diodes and transistors.
I did not do the same for this circuit.
I got away because the lm317 has only 3 pins so I can put it on top --
On it, it will be the same as a mirror --image.
This trick doesn\'t work if you have anything in the DIP pack--upside-
Down is only equivalent to mirmirror-
Image if there is only one line of pins. Using your to-
Draw a scale chart to find out how big the board needs.
I left more space on one side for the power cord.
Score through repetition (
Thin light pressure)
With a matte knife.
Flip the plate, mark it carefully and repeat it on the other side.
You should then be able to bend it several times and it will fatigue and break. (
If you watch the video, my score is not enough.
There are still good advantages in any case. )
Scrub your copper with green padding-
It\'s time to draw.
The first \"skill\" came.
\"Use your perfboard section and ultra-
Fine Point sharpie, when you process all the components on paper, in the mirror, lay holes for all your components-
If you do an image. Ultra-
Fine sharpie is hardly suitable to go through the perfboard hole.
If one side does not work, try the other side. Worst case --
Expand some holes with drill bits.
Put down evenlyspaced 0.
1 \"point make sure the pads you are going to draw are centered so your components can be installed.
Fine time (regular)
And some good ones. Freedom of art.
Draw a wider point around each fine product
Point sales center.
These will be the things you weld the parts later on.
Then draw out the circuit.
The usual width rule applies here--
Leave traces as wide as possible without affecting the design. Thin, ultra-
If you have to meander between pins, fine marks may be necessary.
Otherwise, regular sharpie is a good width for most tracking.
If you have any cluesto-
Where the pin is, it is free to draw the trace first and make an asymmetrical mat to bypass it.
You know where the password is.
Because you marked them with a perfboard, the center needs it.
Easier on your etchant (
Sometimes it also has beneficial electrical performance)
If you keep a considerable amount of copper on the board as a very-low-
Impedance ground path.
It will give you something to do with the chisel. tip Sharpie.
You can do separate power supply/ground plane if you want.
For some circuits, you may need to bypass the capacitor that is scattered between the two planes around you.
If you let the Sharpie ink dry for a while, it will stay better in the etching bath.
Not sure how long \"for a while\" but I tend to wait 5-10 min or so.
This gives you double the time.
Check the circuit, look for an unexpected connection, scratch the point design on the ground plane for fun.
Here, I scraped a little ink from between the two mats. -
Not because they are connected together, but because they are a bit close to the pads that carry high current.
Then, thinking of high current, I enlarged some marks.
Finally, I drew a transistor symbol in an opening section of the ground plane. (
It\'s hard to come up with a good logo on the spot in 5 minutes, Sharpie needs to dry. )
You can scrape the ink off using component leads, sewing pins, paper clips, or something like that.
I used the non-
Business end of small bit.
Etching the board using the etching agent of your choice.
Shameless plug: use cheap, re-
An available etching agent instead of Iron Chloride. (
By the way, you shouldn\'t throw the drain down.
If you do not re-register, please check the phone book of hazardous chemicals disposal companyusing etchant. )
There are a few tips here.
Because you don\'t have a drill-
For the holes you make, an easy way to put them in the right place is to use your perfboard template again.
For a long line like a resistor socket head, I put a point in the middle of the top pin, then a point in the lowest pin, and then, align the two points in the perfboard, then fill in the rest of the points.
In this way, the whole title is on the exact 0. 1\" centers. The ultra-
The fine tip sharp is right through the perfboard hole.
Take a look and make sure everything looks OK and then start drilling once you mess up the whole board.
In addition to this time as a drilling fixture, the performance board appears again.
Align all the holes so you can see the points in it and drill out the pins at the top and bottom as if they were marked.
Now you can paste something in the hole to keep the fixture and board aligned.
I use the tin around me.
Thick Assembly leads or hooks
The wires work fine too.
Once you have the perfboard fixture installed, it takes only a few seconds for the other holes.
This technique is huge for many people. pin ICs.
I drilled another 6 holes on the board to hold the wires from the power supply
Supply plugs so that they can pass through the circuit board as a measure of strain elimination. (
I think I learned it here.
I don\'t remember where it is.
This is a good one. )
Nothing special here.
They are all in a row because you use the perfboard jig.
The pad you drew gives you a good welding surface.
This part is smooth sailing.
If you are not interested in the battery charger circuit, you are finished.
To summarize: Practice on paper first, use sharpie, mirmirror-of different widths-
If needed, take the image with the camera and use the perfboard as a template/fixture as much as possible.
Otherwise, draw the circuit.
If you can make it look a bit modern you will get a bonusarty.
Two notes: Because this is super
Simple charger without turning
Out of mechanism, be very careful, be sure to unplug the batteries when they are charged.
I stopped charging the battery early.
They will last longer if you are not enough
Charge a little anyway
Do not use it for lithium ion batteries or LiPo batteries-
They require constant voltage rather than constant current.