Breadboard Power Supply Stick 5V/3.3V

**Replacement: **PRT-10804. We've made some minor changes to this board layout to prevent the barrel jack from hanging over the edge. This page is for reference only.

This is a very simple board that takes a 6-12V input voltage and outputs a selectable 5V or 3.3V regulated voltage. All headers are 0.1" pitch for simple insertion into a breadboard.

Input power can be supplied to either the DC barrel jack or the two pin header labeled + and -. Output power is supplied to the pins labeled GND and VCC. Board has both an On/Off switch and a voltage select switch (3.3V/5V).

The two pairs of GND and VCC pins are spaced such that when connected to our Basic Breadboard both power busses will be powered.

Check out our Unregulated Power Supply Tutorial!

  • 6-12V input voltage via barrel jack or 2-pin header
  • 3.3V or 5V regulated output voltage
  • ON/OFF switch
  • Output voltage select switch
  • Power status LED
  • PTC fuse protected power
  • 5.5x2.1mm center positive barrel jack
  • 2.15x0.65"
  • Schematic
  • [Eagle Files]( Power Supply - SMD


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • airboss / about 13 years ago / 2

    I feel like this is a stupid question, but is it supposed to blink? I have it hooked up to a LED on my breadboard and both the stick's power light and the LED blink.

  • sparker / about 14 years ago / 2

    Jeremy1998: I am going to modify this in Eagle so that one side is 3.3V and one side is 5V... I think that that sould be like V2 or something...
    I agree. It's trivial to use jumper wire to copy a voltage to the 2nd rail. It's more useful to have both voltages available from a single power jack.

    • Or even better... You can independently select each side... That's what I did in Eagle... I just need to find some help with the "Board" layout...
      I am also going to make one like I described before... And also a USB controlled one...

  • Christopherrrr / about 14 years ago / 2

    It's easy to keep it from getting pulled over the side of the breadboard. After you solder the two pin headers on the underside of the board, grab the black spacer piece with pliers and gently remove it. Now your entire PCB will sit against the breadboard ;)

  • JacopoMTK / about 12 years ago / 1

    Having a Wall adapter power supply that can have both + or - in the "internal/external" part of the connector i need to know if the + in this board is the central pin or in the external shell of the connector.

    Thanks in advance.

    • MikeGrusin / about 12 years ago / 2

      All of our wall supplies and boards that use them, have + in the center, and - on the outside. You can always check this in the schematics as well; the symbol for the jack indicates the center pin and outside sleeve.

  • kjlowe / about 13 years ago / 1

    What's the part number for the SMD switches? Mine broke off.

  • Hi, I want to know if I can connect this board, directly to 12V car battery. Does anybody has some experience about this?. Is there some problem if I do this?

  • Tempel / about 14 years ago / 1

    This may be a noobish question, but when it says it takes a 6-12V input, does that mean actual voltage or nominal voltage? That is, is it saying I can plug in a 9V unregulated adaptor that could waver between 6 and 12V? Or is it saying I can plug in a 12V unregulated adaptor even if it wavers higher than 12V?

    • Tempel / about 14 years ago / 1

      If anyone's curious, I answered my question by experimentation. I have wall wart labelled as 9V, with output that I measured as 13V. Plugging it into the power supply, the power LED didn't even turn on. But nothing broke, so I can confirm an earlier post that a 5V wall wart is able to run the supply at 3.3V

  • I am going to modify this in Eagle so that one side is 3.3V and one side is 5V... I think that that sould be like V2 or something...

  • neurospark / about 14 years ago / 1

    Err, that should have been 100uF capacitor...

  • neurospark / about 14 years ago / 1

    Hello, I was curious as to the manufacturer part number for the EIA7343 110uF capacitor called out in the schematic for the breadboard power supply stick. Does anybody know the part number or additional parameters such as voltage rating, ripple, etc?

  • wcbri21 / about 14 years ago / 1

    Quick question.. The LM317 data sheet recommends only a 1uF tantalum capacitor on the input. Why did you increase it to 100uF?

    • 1uF is the minimum. We don't know what you'll be powering this board with, so we went on the heavier side of filtering with the 100uF option.

  • alfmar / about 14 years ago / 1

    Good: this also works with 5V input giving 3.3V output.

  • Allan2 / about 14 years ago / 1

    I replaced the 330 ohm LED resistor with a 1k ohm one (0603, costs pennies at Digi-Key) and now it's a lot less blindingly bright.

  • Drone: What we need is the same thing with fixed 5V and 3.3V regulators.
    Do you mind explaining why?

  • JoshYoung / about 14 years ago / 1

    Does this board come with the two VCC and two GND pins already soldered or do you have to solder them yourself? Also, does anyone know the part number of the breakout board for the 2x5 ribbon connector in the 4th picture? Last, what is the size of the barrel jack? Does it fit the 9V wall wart that comes with the power supply tutorial? Thanks.

  • ITPro / about 14 years ago / 1

    I have this power supply and I have always used it with a 9V battery. I have a 9V 1Amp wall wart that I am tempted to plug into it... is that a bad idea? what is the max current that this power supply can take? thanks for any info you can give me.

    • russosv / about 14 years ago / 1

      The 1 amp that your wall-wart is rated at should be the max amperage that it can potentially supply. What actually flows through the regulator will depend on what your circuit consumes.
      Since the data sheet rates the LM317 as being able to supply a "guaranteed 1.5A of output current", the regulator should be able to handle 1A.
      In any case, your average breadboarded digital circuit will probably consume a current on the order of milliamps... unless you're dealing with motors or incandescent lights it's not likely you'll draw that much current anyway... anything you're powering with a 9V battery already should be fine.
      (Plus it looks like SF built a fuse into this too!)
      My vote would be yes, go ahead and plug that bad boy in!
      LM117/317 datasheet

  • kewakl / about 14 years ago / 1

    versions with AVR, PicAxe, arduino programming connectors would be nice.

  • blink4jona / about 15 years ago / 1

    Small problem with this board. Notice in the picture the board is tilting off the side of the breadboard? Soldering in the VCC, GND breakaway pins on either side of the board prevents the board from laying flat, and the power cord usually pulls it down bending the pins. I call this a small problem because you can stick some rubber feet/bumpers on the back half of the board to even it out.

  • Vexer / about 15 years ago / 1

    It would be great if this was offered as a kit for learning SMD soldering.

  • Drone / about 15 years ago / 1

    What we need is the same thing with fixed 5V and 3.3V regulators. These should be LDO regulators with SMT. The single regulator on this board looks to be the old LM317 adjustable in SMT package; this is likely not an LDO regulator. Plus I'm worried the parasitics with the SMT 10uF cap; might make this unstable.

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