The Maker Show: Episode 15 - Using Voltage Regulators to Power your Projects

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If you are like me, you have a box of old power supplies.  Those old "Wall Warts" and "Power Bricks" from electronics that have long since been sent to that big recycling center in the sky.  Wouldn't it be cool if you could use them to power your projects?  Turns out you probably can.  BUT you may need to convert the voltages they produce into values that match the requirements of your microcontrollers and components.

In this episode, we'll talk about "Unregulated" and "Regulated" power supplies.  How to figure out what kind you have, and then how you can use Voltage Regulators, like the popular LM7805 to convert the voltages into appropriate levels for your project.  Well cover all the vocab as well so at the end of this you should know the difference between Linear Regulators, Switched Regulators, Fixed Voltage and Adjustable Regulators and "Buck" and "Boost" converters. 

Throughout the episode, I refer to a number of sites, products, and datasheets and I promised to share the links for them all.  So, here they are:

Pull these links up in the browser for the video:

 

Sparkfun Unregulated Power Supply Tutorial:
https://www.sparkfun.com/tutorials/103

Adafruit Power Supply Tutorial:
https://learn.adafruit.com/power-supplies/overview 

Power Supply and Voltage Regulators Video Playlist:
https://www.youtube.com/playlist?list=PL8gw7iuPtx6n6iejk1PfnHaQ7AkGx7F8O

Wikipedia Voltage Regulator Links:
https://en.wikipedia.org/wiki/Voltage_regulator#Active_regulators
https://en.wikipedia.org/wiki/Linear_regulator
https://en.wikipedia.org/wiki/Switched-mode_power_supply 

Arduino Uno Related Links:

Arduino Board
https://www.arduino.cc/en/Main/ArduinoBoardUno

Arduino Schematic:
https://www.arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf

NCP117 5.0V Regulator Used on Arduino Uno:
http://www.onsemi.com/pub_link/Collateral/NCP1117-D.PDF

LP2985N 3.3V Regulator Used on Arduino Uno:
http://www.ti.com/lit/ds/symlink/lp2985-n.pdf

Raspberry Pi Related Links:

Raspberry Pi Power FAQs:
https://www.raspberrypi.org/help/faqs/#power

Raspberry Pi Reduced Schematic:
https://www.raspberrypi.org/documentation/hardware/raspberrypi/schematics/RPI-3B-V1_2-SCHEMATIC-REDUCED.pdf

PAM2306 Dual Voltage Regulator used on Raspberry Pi. Steps 5V in to 3.3V and 1.8V:
http://www.mouser.com/ds/2/115/PAM2306-336770.pdf

Particle Photon Related Links:

Particle Photon Power Details:
https://docs.particle.io/datasheets/photon-datasheet/#power

Particle Photon Schematic:
https://github.com/spark/photon/blob/master/pdfs/photon_v100/photon_v1.0.0.pdf

Particle Photon Design Files:
https://github.com/spark/photon

Richtek RT8008-33GB Regulator used in the Particle Photon:
http://www.richtek.com/assets/product_file/RT8008/DS8008-07.pdf

Datasheets:

Adafruit 30mm LED Dots:
https://www.adafruit.com/product/1547

LM7805 Fixed Voltage Linear Regulator Datasheet:
https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf

V7805-1500R Fixed Voltage Switching Regulator Datasheet:
http://www.cui.com/product/resource/v78xx-1500.pdf

LM317 Adjustable Voltage Linear Regulator:
http://www.ti.com/product/lm317

MP1584EN Adjustable Voltage Switched Regulator:
http://www.monolithicpower.com/Portals/0/Documents/Products/Documents/datasheet/MP1584_r1.0.pdf

Tags:

Devices, Hardware, IoT

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    The Discussion

    • User profile image
      vishalishere

      most informative and easy to understand session for me on power supply and what those volts and amps and switches etc mean..

      Great job Bret!!

    • User profile image
      dsmithson

      This video was awesome!  Super helpful and filled in a lot of knowledge gaps on power supplies that I've never really had a good grasp on.  Nice work!

    • User profile image
      Niner699449

      This was so excellent, Bret. Kudos!

    • User profile image
      JoelBennett

      Excellent video!  I'm really hoping Bret will do more like this.  Maybe something on driving stepper motors from a Raspberry Pi?

    • User profile image
      poteb

      Great video!

    • User profile image
      bratidiana

      Great video!! Thanks Bret!
      What about the usb power adapters, do you recommend them for powering an arduino or a dc motor?

    • User profile image
      BretStateham

      @bratidiana:You can CERTAINLY power an Arduino with them.  DC motor, MAYBE.  Just depends on the voltages/amperages required by the motor.  

      Some of the cheap "5V\2A" (5 volt, 2 amp) power supplies may not actually get you a full "2A".  So beware, your mileage may vary.  It's worth paying a few dollars more for a higher quality one if you plan on using it in your projects. 

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