Introduction: NE 555 Motor Speed Control
A friend of mine asked me to make for him a simple regulator for his slider camera, that looks like the Revolve Camera's control box. So I find an old Italian magazine called "Nuova Elettronica" where there is a simple schematic that you can order. Unfortunately, the magazine no longer exists. So I have decided to replicate the PCB, also in the case someone will want to use this project for other uses.
Step 1: Components and Where to Start
In the picture, I reported all the components that the magazine suggests to use. I've found all from a local store of electronics parts, that he had given me just a different Mosfet (MFT1), signed IRF540n P441Y.
The circuit can reduce a maximum voltage of 15V to a few volts and supply motors and lamps that do not exceed a 5A absorption.
Step 2: The Schematic Draw
I've drawn the schematic with Frizzing. Here there is the picture and the pdf with a modification respect the following step's pictures: a bridge that I've deleted. Just an experiment.
Here there is the pdf of the printed circuit board.
Step 3: Scissors, Alcool and Iron
Now the print: you need the PNP sheet (press-n-peel) and a LASER PRINTER (the ink printer can't be used)
After printing the circuit on a PNP, you have to clean the copper with alcohol or kerosene distillate oil or a good degreasing as you prefer. You can also prepare the surface sanding it with sandpaper.
!!! PAY ATTENTION !!! : because it will be ironed onto the copper, that is the bottom surface, you DON'T HAVE TO FLIP the image I've posted in the previous step. Just print and put it on the copper.
The iron must not be too much hot: 1/2 or 3/4 of the scale will be enough, otherwise the circuit tracks will blend together over the copper surface. I say it for the experience.
Put a piece of fabric between the copper and the iron, push and make warm to the surface evenly for a minute or two. Then let cool the copper before touch it and then gently and carefully remove the blue sheet to reveal the blue drawn on the copper.
If there is some spots or interruptions on the tracks, use a permanent pen to draw and repair the circuit.
You can see in the pictures the different color of my reparations even if I have prepared the surface before. I still don't know why these bubbles come.
Step 4: A Bath Into Ferric Chloride (FeCl3)
Now the chemical part:
You must buy a bottle of Ferric Chloride (FeCl3) to remove the copper from the surface.
!!! PAY ATTENTION !!! : Use glasses and gloves When You use this substance, Because It's corrosive to the skin, and watch out your clothes, Because if even a single drop goes on them, they will be permanently ruined.
Put it into a plastic recipient copper, not aluminum or other metal, and then put as much FeCl3 until to submerge the copper.
The chemical reaction ( FeCl3 + 3Cu -> 3CuCl + Fe(s) ) will be faster with agitation and making warmer the solution.
When the reaction will be completed, and all the copper will be gone, wash the fiberglass sheet with water.
Step 5: Just a Little Bit of Color
I've painted the back of the PCB, because another friend of mine have told me, after showing the first PCB that I've made for another instructable:
"Si ma potevi colorare quella basetta, invece di lasciarla di quel verde merda anni 70"
"Yes, but you could paint the PCB, instead to leave it with this 70's shitty green."
So...there it is.
Step 6: Clean the Surface & Dremel's Part
Now you can remove the blue that covers the tracks with acetone, revealing the copper, as in the picture.
I've used a 1mm diameter drill bit, on a drill press to make the holes perpendicular.
Step 7: Components
Then I've started to solder the components onto the circuit, from the lower components to the taller.
Step 8: Step 7: Finally: Check the Circuit Tracks
Finally, to check if everything was done well, I checked out with the multimeter, set to ohms, all the tracks.
I've closed up everything in a plastic box with a double deviator to change the rotation of the dc motor.
As soon as I can, I'll add other steps, pictures and video to explain it properly how to do it.
Hope this tutorial will be useful for someone. If there is any question or suggestion on all the steps, let me know it.