Today we will cover how to make a simple voltage regulator to power a prototyping board with 5 Volts, using different voltage input methods and values (8 to 35V).
My little mod uses an L7805CV voltage regulator to give a fixed 5V output to the breadboard.
It is fitted with pin headers, screw terminals and 9V battery contacts, to operate from a variety of power supplies, although its main purpose is to be portable.
The Instructable will be composed of easy mini steps, one per part, so don't be alarmed by looking at the quantity of them!
Step 1: The Parts
- L7805CV voltage regulator. I recommend to attach a heatsink to it, as you might get burned or damage the regulator if you have a high power output.
- a switch
- an indication LED
- a 200~300ohms resistor for the LED, its colours should be: [ RED | any colour | BROWN ] (I know the picture is wrong, sorry)
- 3 headers
- 9V battery contacts
- 24x3 soldering board piece
- a breadboard
- a sheet of plastic onto which we will glue the breadboard and the regulator board
The needed tools are a soldering iron and a hot glue gun, which can be replaced with any liquid glue.
To cut the soldering board I use a pair of pliers. Hold it where you want to break it (along a line of holes) and bend it with your hand. It will start cracking, do it along the line to weaken it, then snap it.
Step 2: Solder the Headers
1st line: input voltage
2nd line: ground
3rd line: 5V
Put the headers at one end of the board, and solder them.
They will be useful to pick up or supply voltage using female headers (like computer fans, etc...)
Step 3: Solder the Screw Terminals
I soldered them slightly sideways because I wanted to keep everything slender. Just put one pin in the input line, and the other in the GND line, as shown in the pictures. You may add a 3-pins terminal to have access to 5V as well.
Step 4: Solder the 9V Contacts Wires
Step 5: Solder the Switch
Step 6: Solder the L8705CV
Solder it facing away from the already placed components.
Step 7: Solder the Resistor
Solder it along the 5V line.
(The picture shows a 22 ohms resistor, I changed it later to a 270 ohms one)
Step 8: Solder the LED
The positive lead (the one with the smaller part inside the cap) goes in the 5V line, next to the resistor end.
The negative lead, the one which has a cut in the plastic cap and has the bigger part in it, goes in the GND line.
Step 9: Solder the Wires
The GND wire is a straight wire that connects ALL the leads on its line. Start with this as it can become difficult to solder with another wire next to it.
Be sure to leave a gap between the leads of the switch, as well as under the resistor!
Step 10: Test It!
If it doesn't, check all the soldering points to see if they are in the right place and conduct as they should.
Step 11: Solder the Breadboard Powering Wires
Keep the wires long (some centimeters) as we will cut them down to the right length after we glue everything together.
Step 12: Put It Together
Cut the wires to the exact measure and insert them in the breadboard.
Step 13: Done!
I hope you found my Instructable useful.
Thanks for viewing, have fun with your new portable breadboard!
That's all, folks!