Whenever I use a circuit in a project, I always like to breadboard it, to make sure it works and tweak it if need be. I recently purchased a power supply, so i wouldn't always have to use a battery to power my breadboarded circuit. It comes with connectors, but they are a pain to connect to the breadboard. So, I decided to make this little power connector, so all I have to do is plug it into my breadboard, and power up the power supply. I wanted to be able to cut the power to the breadboard independently of turning on and off the actual power supply, hence the toggle switch. It is up to you whether or not to include this when building your own breadboard power connector.
Step 1: What You Will Need
- Strip board - 7 rows x 20 holes (or any other kind of pc board. Strip board is the easiest thing to use for this, however)
- Header Pins - x 4
- Toggle Switch - x 1 (This is optional for reasons previously described)
- Wire - 26 gauge - Whatever length you want (I chose a length that would suit me and my work area - the distance from my power supply to where I work)
- Extra component Leads - x 2
- Breadboard (for test-fitting your header pins)
- Wire Strippers
- Exacto Knife or Box Cutter
- Sharpie - optional
- Soldering Iron
- Helping Hands - optional
- Drill or Drill Press (not pictured)
- Drill bit (3/32" was perfect for my purposes - not pictured)
- Dremel (alternatively you could use an exacto knife to make the track cuts - not pictured)
- Ruler (not pictured)
Step 2: Prepare the Header Pins
- First you need to use either pliers or clippers to split each individual header pin apart. This was necessary for me because the spacing between the wasn't large enough for them to be inserted into the strip board holes at a diagonal angle. This will make more sense later.
- Then you need to sue pliers or clippers to break off the plastic housing from around the metal pin. This will make it look better and make soldering easier.
Step 3: Score and Snap the Strip Board
- Stick your component leads through the holes of your strip board so you know how long the board needs to be. You want the long, connected strips of your board to go horizontally across the breadboard, as pictured. Make a sharpie mark of where you need to cut the board.
- Do the same thing for the width of the strip board. Use your switch to help you measure and make your sharpie mark.
- Use a ruler and score the board with an exacto knife or box cutter. Snap the board over the edge of a desk.
- You now have your board. I'm basing my measurements off of a standard breadboard, and the dimensions were 7 rows by 20 holes.
Step 4: Drill the Holes for the Switch
- Use your switch to measure and mark where the holes for its legs will go. This is necessary because usually the legs of the switch don't fit into the holes of the strip board.
- Use a drill or drill press to drill the holes for your switch. 3/32" worked perfectly for the switch I used.
- now just stick your switch into the holes and move on to the next step.
Step 5: Time to Solder!
- Do not make the same mistake I did! Make the track cut in the first, before soldering. This has to be done between 2 of the three switch legs.
- Next solder the header pins into the board. Make sure they line up with the power rails on the breadboard.
- Strip the insulation from both ends of each of the wires. Tin one end
- Then solder each wire's non tinned end into one end of the strip board
- Bend one of your component leads into the shape shown and solder that from the positive wire to the positive row (for me, this was the row farthest to the left). The great thing about strip board is that as long as two things are soldered in the same row, they will be connected.
- Make sure the negative wire is in the same row as the switch's legs. Make sure that the track cut is between the leg the wire is connected to and the middle leg. You can see it in the picture
- Take your other component lead and solder it from the middle leg to the negative row. You can see the track cut in this picture. - - Try to do better than men and not get so much solder every where.
- The reason that I have the positive connection on top of the board and the negative jumper on the bottom is because otherwise the positive and negative terminals of the power supply would short, a very bad thing. I also didn't feel like making additional track cuts.
Step 6: Twist the Wires
- Twist the wires leading from the breadboard together, in order to keep them neat.
- Secure the ends with electrical tape to keep the wires from untwisting. Alternatively, you could use heat shrink. Make sure to leave enough untangled wires at the end to connect to your power supply.
Step 7: Plug It In
- Fit the header pins into the power rails of the breadboard. Make sure the positive connects to the positive and the negative connects to the negative.
- Connect the wires into your power supply and adjust the output voltage and current to suit your load.
- You are done! The great thing about including the switch is that you can cut the power from the circuit while still having the power supply on, for sometimes it can be difficult to reset the output every time you want to turn the supply off and then on again.
- Some improvements could include adding banana plugs so connecting and disconnecting it can be easier than adjusting the screw terminals. You could also add and on-indicator led, so you know when the switch in in the on position, or simply add some labels.