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33 Amp 12 Volt Power Supplies

These are 12 volt, 33 amp switching power supplies suitable for a range of high current uses. We used them for a public art installation that we were hired to engineer and install and they performed admirably for 3 months. We powered more than 200 feet of WS2812 LED strips with a couple of these power supplies.


The power supply is very clean, here’s a scope trace taken with a load (of LEDs) of about 18 amps.

Visit the product page in the Power Supplies section.



  • Output Volts: 12 volts DC (adjustable from 9.5 to 14 volts)
  • Current: 33 amps (maximum)
  • Ripple @ 18 amps: <15 mV
  • Input volts: 120/240 60/50 hz
  • Input Current 6.5A rms
  • Dimensions: 2″ x 4.5″ x 8.5″ 50.8 mm x 114 mm x 215 mm
  • Open Frame (not waterproof)
  • 1.7 lbs
  • By Paul Badger on June 21, 2016.

    New Product: BUB III


    Future Technology Devices International makes many different TTL Serial to USB chips.
    One model, the FT232R, is used in boards like the
    The AdaFruit FTDI friend,
    SparkFun FTDI Basic,
    Modern Device BUB I and
    Modern Device BUB II.
    It’s not the cheapest, smallest, or most functional FTDI chip– just the most popular.

    Presenting the BUB III, designed around the FT231X QFN-20, a 4x4x.075 (mm) chip.

    You’ll notice it has a micro-USB jack, instead of a mini-USB one. Micro-USB jacks have a bad reputation for coming off boards, because they have less surface soldered on the board. We spent a fair amount of time finding a micro-USB jack with extra prongs and adding vias to reinforce the smd pads. Our destructive testing of a few of these boards shows that our efforts to toughen up the boards were successful. The jacks take quite a bit of muscle to break, and we think they will stand up to abuse as well as mini-USB jacks.

    Moving the header to the bottom makes the board even smaller, and saves us time in production.
    Both LEDs are reconfigurable (should you want to reconfigure them) with FTX-prog

    It’s the BUB you love, smaller, slicker and reborn with an all-new brain.

    Be one of the first 6 customers to use coupon code freebubiii and get a free BUB III with your order! (order total must be over $10)

    Go check it out in the shop!

    By Nadya on November 10, 2015.

    New Product: Rigid RGB LED Strips

    rigid_rgbled_threeWe picked up these nice Rigid RGBLED Strips from one of our suppliers for a good price. They contain 30 5050 RGB LEDs which seem to be standard super-bright LEDs, they are 12mm wide and 500mm long with headers every 50mm where they can be cut and soldered. The have nice polarized connectors and six inches of cable on the ends which makes mating them in series simple and quick and easy. Priced low enough that you could afford to take off the LEDs and use them on other projects (.20 ea). The resistors are sized to lend nice balanced white light that is not too cold in color, when powered from 12 volts. The 12V trace which looks to be about 60mils wide is mirrored front and  back for extra current-carrying capability.

    Continue Reading →

    By Britton on October 6, 2015.

    RFM69 Radios

    New Radios!

    The RFM69CW radio module by HopeRF is a compact, powerful radio transceiver module for swapping data packets in the 868 MHz ISM band, using standard and enhanced FSK modulation. The radio is great for sub-compact designs; just 4mm of mounted height from using an SMD precision crystal.

    Though consuming a similar level of power, the RFM69CW receiver section can decode fainter signals than the classic RFM12B, so it has better receive sensitivity. The transmitter section *maximum* output power is +13dBm, considerably higher than the +5dBm of the RFM12B. The current drain at these (adjustable) higher power settings is correspondingly higher though. With the better receiver sensitivity, many applications will not need to use the higher transmit power settings, potentially saving on battery life.

    Compared with the RFM12B, pairs of RFM69 modules will generally have greater range and/or better penetration of walls/ceiling than when using pairs of the classic RFM12B.

    The physical module is compatible with the PCB footprint on all current JeeNodes and JeeLinks. For details of the fast-evolving level of software support, see this Forum topic on the JeeLabs forum.

    Control is via a fast SPI bus with reduced loading on the microcontroller, another nice advantage with the radio. The recommended power supply range of 1.8 < Vdd < 3.6 V can squeeze almost the last energy out of depleting batteries without needing a boost converter.

    An antenna must be connected to RFM69 module – for 868 MHz, an 82-mm (quarter wavelength) wire can be used (not included). Operation without an antenna at the higher transmitter power levels risks permanent damage to the output stages.

    Marking Convention: a yellow spot on the top of the transceiver chip indicates optimized for the 868 MHz ISM band. You can have confidence that you are building your project with a fully functional module!


    • More transmit power than the RFM12B (but more current required).
    • Better sensitivity on receive.
    • An RF signal strength is available
    • Fits the current RF12B footprint
    • The JeeLabs driver fully supports the radio with only one definition change at the top of a sketch.
    • RFM69 and RFM12B radios may be mixed in a JeeNode network and talk to each other.

    For detailed specifications, see HopeRF’s RFM69CW documentation.

    The RFM Board provides convenient signal breakout with an option for connecting to 5V power systems.

    Digital Smarties (The JeeLab Shop) stocks a 868 MHz version of these modules with EU prices. Both Modern Device and Digital Smarties (Jeelab Shop) have the 434 versions.

    Right now we are selling these on RRM12B boards and JeeNode kits.

    By Paul Badger on March 19, 2015.

    New Product – ExtraCore MD – Alarmingly tiny Arduino Clone!

    Dustin Andrews created the first ExtraCore Arduino which is the size of a postage stamp. We sold the first batch we had, and by that time, the original was extinct as Dustin had moved on to another job and didn’t want to make more. We decided to respin the board with a few improvements and a smaller chip. The result of our efforts is in the shop  here .

    The ExtraCoreMD, as we’re calling it, is a minuscule form factor Arduino clone, ideal for applications where space and weight need to be kept to a minimum- aircraft, robotics, fashion, wearables. The size of the board is .92″ x .825″ (21mm x 23mm), and it is manufactured on 1.3mm PCB for a sleek height profile of only .09″ (2.2mm). The board is small enough to conceal in jewelry, or DIY musical greeting cards, or wearable tech, if you’re crafty.

    Programming is through our USB BUB or any standard FTDI cable, unlike the first ExtraCore. We also made one non-fatal mistake in the boards, although we are revising them immediately. The labels on the VCC and Vin are just swapped.

    We cooked up a quick example app, just to prove out the board, using 18 pins (all the I/O except RX & TX) LED’s with a basic loop. Keep posted for more experiments using this board.


    There are more details on the product page:

    We’re giving away ten of the boards, with orders over ten dollars. Use coupon code EXTRACOREMD.

    By Britton on January 23, 2015.

    Free Shipping Every Weekend!

    We offer Free USPS First Class Domestic shipping every weekend for orders over $10 to help you save a few bucks here or there. We tend to start the weekend early, so Free Shipping gets activated around 3pm EST Friday, and deactivated at 10am Monday. If for some reason the option is not available, please feel free to contact us and we will fix that!

    Despite offering this for quite some time, I have noticed that not everyone takes advantage of this offer. When checking out, make sure you select the option “Free Shipping on Weekends, Domestic US only.” Please note that orders that are over 13oz in weight are not eligible for First Class Mail, and you will have to use another option.

    By Britton on December 5, 2014.

    Wires, more wires, in all gender combinations


    These are 12″ long ribbon-wire jumper cables suitable for a wide variety of temporary or permanent wiring tasks. These are much more robust than flexible breadboard wires which are fine for quick prototypes, but do not hold up to soldering.

    We’re even including some double-long male headers with the female pins, as handy gender changers.

    They’re in the shop and ready to go.
    I’m giving away ten of ten of them for free. Use coupon code RIBBON_WIRES. Limited to one per person on orders over $10.

    By Paul Badger on November 4, 2014.

    A hybrid power connector


    You love screw terminals. You love barrel jacks.

    These things seem so standard to you, so convenient, and you dream of their lovechild, a sweet hybrid of convenience, solder-free terminals coupled with that 2.1mm silver power plug that powers myriad devices (e.g. Arduinos and most of the boards we sell).

    Believe or not – this slightly monstrous adapter lives!  Soldering standard barrel plugs onto wall-adapter and battery-pack wires is not rocket science, but there are two principle challenges:

    1. You have to put the barrel plug insulator onto the wires, in the correct direction, BEFORE you solder the wires.
      This simple act is cunningly easy to forget and evades me a fair percentage of the time I solder plugs on wall warts and guitar cords. So I end up with a perfect solder joint on the connector, and the insulating sleeve is lying on the bench, and I have to do it all twice.
    2. The other challenge is soldering well enough, and making tidy enough solder joints, so that the sleeve will slide down over the wires and screw on. This never bothers me anymore, but it often taxes my student’s soldering abilities.

    This screw-terminal power plug eliminates both problems, perhaps at the expense of aesthetics. Also you don’t really have much strain relief with this jack, but it could easily be added with hot glue or epoxy putty. Perhaps at the further expense of aesthetics.

    This also a great way to reuse all those power adapters in your junk box.

    We have a short tutorial on using the plug below.



    Unscrew the terminals,

    Tin the wall-adapter or battery-holder wires, Tinning the wires is not strictly necessary but is a good idea.

    Insert the wires into the adapter. The marked “+” terminal is positive. This is way more standard than center-negative. Center-negative adapters do exist, but not in Arduino land. Double check your specs and the polarity.


    And screw the terminal back down again.


    If you’re seeking permanence, the wires can be soldered in place, though it takes a while. (this iron is off, use a hot one for best results).



    It’s ready to go in the shop here! It’s never too early for nerd gifts for the holidays.

    By Nadya on September 30, 2014.

    Creating a script to set your color palettes in Eagle.

    Screen shot 2014-09-26 at 10.17.26 PM

    A beautiful palette in Eagle. It’s still a work in progress.

    This is tutorial to make a script that will set your color palettes in Eagle. Eagle has horrible (and limited) default colors and users have been complaining about them, and the lack of color palette functionality for the last 15 years, with absolutely no response. According to the managers at CadSoft the next revision is slated to fix some of the multitude of interface issues that are wrong with Eagle. (Don’t get me going again…)  If you agree with me, you might wander over to the Eagle support forums at Element 14, and speak up about fixing the color palette, as well as storing color palettes in files.

    Anyway here’s how to make a groovy script that will set your favorite palette colors. One use for a script of this type is to reset your colors if they should ever become compromised, but you can also move color palettes between computers, and include them with files that you send to others, so that they can see your beautiful work in the colors in which it was created. To set the color palettes in Eagle, just run the script.

    (Sorry these are the mac instructions – windows shouldn’t be that much different. I think the file name for .eaglerc might be different. Feel free to mod my instructions for Windows  and repost.)

    • The first step is to edit one of the Eagle palettes to your taste and add some better colors. Don’t forget that the colors are arranged in vertical pairs in the palette. When you choose the top color in the pair in which to have a layer displayed, when the layer is selected, Eagle will use the bottom color of the pair to display the selected/active item in the layer.. If you choose the bottom color in the pair for the layer, elements do not change color when selected. So colors directly above each other in pairs should usually have a great deal in common. I usually make the selected color brighter (more saturated to you artists out there), and more opaque, assuming that when you select an item, you generally want it to pop out at you.

    • Once you have finished your masterpiece palette,  quit Eagle. This is important because Eagle has some bizarre ideas of when to write files, so lots of information is stored and then written out when you quit. If the program crashes, well, you lose 🙂

    • Open the Terminal and type the command “cd ~” (no quotes) That will get you to your home folder just in case the terminal
    doesn’t open with your home folder as the current directory

    • Next type the command “ls -la” (no quotes)
    That will list all the files including invisible files – which .eaglerc is, since it begins with a period.

    • Look for a line similar to this
    -rw-r–r–     1 userName  admin      29110 Sep 26 20:29 .eaglerc

    If you find .eaglerc all should be well.

    • issue the terminal command “less .eaglerc”

    • When the file opens in the terminal, use the arrow keys to scroll through the file (it takes a while!) until you find
    a line like this:
    Palette.0.0 = “0xFF000000”

    These are the palette entries.
    Palette.0.x entries are the black background
    Palette.1.x entries are the background
    Palette.2.x entries are the grey or colored background

    You can copy any of the palettes for your script, or just one. I only use the white background, so I just copied the 1.x entries etc.
    One strategy if you didn’t want to change the black and white palette default colors would be to change the colored background.

    Copy the palette/s you want. Paste it into a text editor.  At this point you can exit the terminal if you want.

    • Next you need to use the text editor of your choice to search and replace commands to change the text from the form

    “Palette.1.1 = “0xB43232C8”

    to the form
    “set palette 1 0xB43232C8;”

    If you have any practice at all searching and replacing, this should only take four or five steps of search/”replace all”, to whip the text into the correct form.

    next append the entries:
    “set palette black;”     before the black palette entries
    “set palette white;”     before the white palette entries
    “set palette colored;”   before the colored palette entries

    you can add blank lines if you want for formatting – they are ignored.
    comments may be added with a # sign beginning the line and ending with a semicolon

    •    Here’s the head of my file for an example.

    # MyDefaultColors.scr;
    # Set the default colors in Eagle Cad;
    # colors are stored in .eaglesrc in your home directory;
    # open that file and copy the current colors;
    # Then edit in a text editor to the proper format;

    set palette white;
    # you can’t change index 0 in the white palette;
    set palette 1 0xB41CC2FE;
    set palette 2 0xB4002400;
    set palette 3 0xB4008080;
    set palette 4 0x96CE0029;
    set palette 5 0xB4800080;

    • That’s it – save your file as “MyDefaultEagleColors.scr” or anything you wish, just be sure to use a “.scr” extension.

    If you get an error in Eagle when you run the script with Run Script  you probably just have a formatting error. You can get an example of a working script from the  “defaultcolors.scr” script in the Eagle/scr folder, to get the syntax right.

    Happy palette making. This will give you a way of transporting your colors between computers and sending to others to view your Eagle files as you created them.

    Remember you don’t have to get the palette right the first time, you can repeat the process any time, although it is a little tedious. In the meantime, you might speak up in the Eagle  Forums at Element 14 and ask for a load and save button in the set palette window, which would make this tutorial blissfully obsolete.

    By Paul Badger on September 26, 2014.