Intro: Powered Breadboard Workstation
A powered breadboard is an enclosure with a built in fixed and variable voltage supply and the breadboard is used to test circuits. Wires and components are simply pushed into the holes to form a completed circuit and power can be applied. One of the main advantages of using a breadboard is that the components are not soldered and if they are positioned incorrectly they can be moved easily to a new position on the board. For the past 6 months I'd been using batteries and 5v and 12v breadboard voltage regulators for my projects, it could get really annoying having two ac power cords plug in on your breadboard and running out of batteries just when you need them, not to mention the money spent on batteries. So I started to look for a powered project breadboard and they run anywhere from $80.00 to $199.00 dollars. The $80.00 is a basic one, one fixed +5vdc and a 0-16vdc variable voltage. The $199.00, one 5vdc fixed and two 0-16vdc variable voltage.
So here are the features of my custom made Powered Breadboard Workstation:
- Three fixed power output: 5vdc, 9vdc and 12vdc at 1.5A.
- One adjustable power output: 0-24vdc Variable @500mA.
- Digital Voltmeter.
- Flexible project light. ( for those dark spots)
- Anti-static Ground lug. ( to ground yourself for those delicate circuit components)
- Input: 120vac @50-60Hz.
- Grounded case.
- Solder-less breadboard with 2390 tie points.
- Power switch with light.
- Short-Circuit, Overload and Fuse protected.
Step 1: Material and Tool List
www.taydaelectronic.com Very good and cheap electronic components online store, they let you buy just what you need. If you need one capacitor you'll get one capacitor. Not like other online stores that have a minimum quantity purchase.
Voltage Regulator: 7805, 7809, 7812 and LM317T (0.94 all together)
(8) 10uF, (7) .01uF, (1) 4700uF, (1) 100uF. ($1.27)
(9) 1N4001 Diode ($0.18)
(4) 220 1/2w resistors and (1) 100 resistor ($0.25)
(1) 5K Taper Potentiometer with solder lugs ($0.50)
(4) LED 3mm Green ($0.08)
(4) 3mm Bezel LED Panel mounting clip ($.16)
(6) Binding Post (2 Black and 6 Red) ($1.50)
(1) 220vac Glass fuse 5x20 10A fast acting ($0.17)
(1) Rocket switch red on/off spst with light 15A, 250vac panel mount ($0.38)
(1) Green Plastic knob with pointer ($0.22)
(4) Heat sinks TO-220 4 fins Aluminum ($0.96)
(1) Copper Clad Board PCB single sided 6x6 ($1.56)
(2) Cooking Baking pan (13.2in x 9.2in) and (1) bread and loaf baking pan (8.4in x 4.4in x 2.5in) $3.00
(1) Reading light $1.00
Amico 3 pin on/off round rocket switch 6A/125vac, 3A/250vac (10) for $7.00
(1) 120vac 60hz, 16 to 24vac transformer $12.00
(1) AC power inlet, male with fuse chamber (screw) $1.75
(1) 3-conductor power cord (computer or power supply cord) $3.95
(1) Digital voltmeter ($ 5.00)
6/32 bolts with nuts
1/2 " sheet metal screws
Heat shrink tube
PCB Etchant solution
Set of drill bits
Hook up wire ( Red and Black)
A drill driver
Dremel with cutoff wheel
Step 2: Enclosure
We are going to start with the top piece and the control panel of the enclosure. See picture 1
Take the bread pan and mark a line 1/2" from the bottom, do the same on the other side. Take a square and make a 45 degrees line across the side of the bread pan, do the same on the other side. Now draw a line across the pan connecting both side together . See picture 2,3 and 4. Now cut the piece off using the dremel cutoff wheel, see picture 5 and 6. leave at about 1/4 in off of the opening to glue the front panel to the bread pan. see picture 7 and 8. And last, cut off the opening for the AC power inlet and the main switch see picture 9, 10 and 11.
Now grab the cookie baking pan and place the bread pan on top of it and trace the inside of the bread pan on the cookie pan and cut it off, see picture 12, 13, and 14. Next drill a 1/4" hole on one side of the cookie pan, this is to run the wires of the LED light through to the PCB. See picture 15 and 16.
Step 3: Main Switch, A/C Power Inlet and Transformer Wiring.
I decided to separate this part of the instructable from the other steps. The reason being is that on this step we are going to wire the components that deal with 120vac, high voltage. Dealing with 120v is dangerous and I really encourage you to pay close attention to this step, I'll be as clear as possible.
Lets get familiar with each component and each terminal.
AC POWER INLET (picture 1): There are three terminals on the back of the device.
• Top terminal is labeled E = Earth which means Ground.
• middle Left side terminal is labeled N= Neutral.
• bottom left side terminal is labeled L= Line.
Main switch with light (picture 2): There are three terminals, and they are labeled 1, 2, 3.
• 1= load
• 2= Line
• 3= Neutral ( this terminal is brass colored, so it is easy to identify).
Transformer (picture 3): The one I used came from a cheap ($8.00) doorbell. There are 3 wires on one side and two screw terminals on the other, which are the negative and positive terminals.
• Green wire= Ground
• White wire= Neutral
• Black wire= Line
Now take a look at the drawings picture 4, it shows the wiring connections. I bought an extension cord at a thrift store for $1.50 you need this size of wire, is a 14 AWG stranded wire. YOU MUST USE A 14 OR 12 AWG 15 to 20 Amps stranded wire, to wire this three components together. See picture 5 & 6.
Wire the Ground terminal of the AC power inlet (labeled E) to the grounding lug and to the green wire of the transformer.
Wire the Neutral terminal of the AC power inlet (labeled N) to the white wire of the transformer and to the terminal 3 brass colored of the main switch..
Wire the line terminal of the AC power inlet (labeled L ) to the main switch terminal labeled 2.
Wire the main switch terminal labeled 1 to the black wire of the transformer.
The two wires on the other side of the transformer are the secondary output voltage AC of the transformer, 30VAC leads, and they go to the PCB.
see picture 7. Do not forget to install the glass fuse in the AC power inlet
Step 4: Front Panel and PCB
Grab the piece of material of choice, 1/8" thick see picture 1. Trace the opening of the bread pan on your panel material and cut it. Once you have test to fit the panel, arrange the components on the piece ( Binding post, potentiometer, led holders, switches and the voltmeter) where you want them, mark them and drill them out see picture 2, 3 and 4. For the voltmeter opening use the dremel's cutoff wheel.
• Led holder 1/4"
• Switch 3/4"
• Binding post
• Potentiometer 1/4"
I used quick disconnects for all of the components just in case I need to replace any component in the future. Solder the wires to each component and cover the joints with heat shrink tube see picture 5-9. Now is the time to work on the LED light, solder 12" of wire to the LED light see picture 10, and run the wires through the hole drilled on the side of the enclosure to be solder to the PCB see picture 11 and install the light in place see picture 12, this is the time to install the breadboard use the #6-32 bolts ad nuts. Now install four 1/2" spacers on each corner on the bottom of the 2nd cookie pan (see picture 13). Clamp both cookie pans together and drill some holes evenly around it ( 3 per side and 2 on top and bottom) and rivet the entire enclosure. Now the enclosure should be looking like picture 17.
Step 5: PCB and Electronic Components Installation
Now fun time. print out and etch the PBC see picture 1. There are a lot of videos on how to do this, I used the press & peel blue transfer paper see picture 2, 3, 4 and 5. Once your PCB is ready, start soldering all the 1N4001 Diodes, 0.1uF Capacitors second, the 4700uF capacitor third, all resistors fourth, and all the Voltage regulators (see picture 6, 7, 8, 9 & 10). Solder all the leads going to the front panel last and make sure you label each wire so they do not get mixed up. Now find a good place to bolt down the PBC in the enclosure mark the mounting holes and drill them, see picture 11 & 12. install the PBC in place. And last wire all the panel components to the PBC, see picture 13 & 14. Now test the circuitry. Plug in the powered breadboard and test each binding post for proper voltage. Now screw on the enclosure and glue or screw the front panel and you are done. Finally!!! Below I've attach the PBC, the component place, values and the diagram. In the wiring diagram there are 1N4004 Diodes, replace them all for 1N4001.
Step 6: Conclusion
In conclusion this project introduced you to what it takes to built a powered breadboard, circuitry, PBC etching, soldering and design. A $65.00 dollars project for something that will normally cost you $120.00 to $200.00. This powered breadboard has more outputs, two extra features that are a must (anti-static ground lug and LED light) when prototyping circuitry, digital voltmeter display. Yes, it may not look nice and fancy like the ones from the store but it works just the same for less money. This is not a project that will seat on a shelf for years, is something that will be used all the time for all kinds of projects. If you do not want to make a powered breadboard, make a power supply. Just get an enclosure deep enough to fit the transformer and big enough to fit all the components and PCB. Now is time for me to move on to my next project.
Thank you for reading and taking interest in this project. Good luck.