ears to our world

At ETOW, we believe access to information is access to education. We provide innovative, simple and appropriate technologies to schools and communities in remote, rural and impoverished regions of our world.

Click here to Purchase a HumanaLight at Universal Radio.

Click here to purchase a HumanaLight at GigaParts.

NEW: Click here to order the new HumanaLight enclosure from HARDENED POWER SYSTEMS.

The ETOW HumanaLight

Listen and Learn: It’s ETOW’s tagline, but it’s also a commitment we at ETOW have made to those we serve.

We’ve been doing just that, and we’ve learned how important the little LED lamp on our self-powered radios is, especially to communities that live largely or entirely off-grid.

So we’ve chanced upon a bright idea: an easy-to-build kit for a bright, long-lasting LED mini-lamp that’s powered by a surprising, but ubiquitous, resource: the residual energy in depleted AA batteries.

The finished devices used in the field are built mostly from recycled parts for an environmentally light footprint, can be sold and the profits reinvested in local schools, health clinics, and other crucial services.

Introducing the HumanaLight Kit

In 2014, we decided to make a simple kit of the HumanaLight they we can sell on the market and use the proceeds to fuel our mission. We imagine school children, Makers, experimenters and hobbyists will all find this a fun kit to assemble and a useful light in times of emergencies. 

Ears To Our World, and those we serve, are very much in debt to our volunteer engineers who made this possible. Many thanks to Gregorgy Majewski for developing and designing the original HumanaLight circuit--he put many hours into testing this amazingly efficient circuit and bringing it to fruition. We also thank David Cripe (NM0S) for designing the HumanaLight circuit board and kit--David made this kit affordable and functional. 

You can purchase the HumanaLight kit through Universal Radio or GigaParts.

If you have recently purchased a HumanaLight kit, you can watch the video below or scroll down to find full assembly instructions:

Instructions for Assembling the ETOW Humana Light Kit

Prepared by Gregory Majewski • 14 February 2014

Materials and Tools Required:
•    Low wattage (25 to 45) soldering iron with pencil tip,
•    Diagonal or Flush Cutting Pliers,
•    Long Nose Pliers,
•    Thin Rosin Core Electronics Solder.

Note: The orientation of the LED, transistors, and battery holder are printed on the HumanaLight circuit board. See detailed photos below:

To Assemble the HumanaLight:

Step 1

  • With the long-nose pliers, bend the leads of the inductor (black ½” cylinder) to fit into the holes on the board marked “L1.” Insert the leads into the L1 holes.  
  • Solder these leads to the pads on the back of the board with the soldering iron; trim excess leads from the pad side with the cutting pliers (or nail clipper).   

Step 2

  • With the long-nose pliers, bend the leads of the 10 kilo-ohm resistor (the larger resistor, which is banded brown/black/orange) to fit into the holes on the board marked “R1.” Insert the resistor wires into the R1 holes.  
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers.    

Step 3

  • With the long-nose pliers, bend the leads of the 100 kilo-ohm resistor  (the smaller resistor, which is banded brown/black/yellow) to fit into the holes on the board marked “R2.” Insert the resistor into the R2 holes.  
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers

 

HL-4.jpg

Step 4

  • With the long-nose pliers, bend the leads of the capacitor marked “471” to fit into the holes on the board marked “C1.” Insert the capacitor into the C1 holes.  
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers.   

Step 5

  • Insert the LED with the flat side away from the inductor into the LED holes on the top of the board. (If you are uncertain of their orientation, skip this step until the end, as you can test their position before soldering.)  
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers.
  • Note that the LED can be soldered flat-mounted directly to the circuit board, or the leads can be bent at a right angle (better for forward-facing flashlight use). See example in image at the top of this page

Step 6

  • Insert one of the “2N3904” transistors with the flat side facing outwards into the holes on the top of the board marked “Q2”. The orientation is indicated on the board. 
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers

 

Step 7

  • Insert the remaining “2N3904” transistor with the flat side facing outwards (opposite of Q2) into the holes on the top of the board marked “Q1.”
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers.

 

Hint: Use tape to help hold the switch on while soldering.

Hint: Use tape to help hold the switch on while soldering.

Step 8

  • Insert the On/Off Switch into the holes marked “SW1.” Solder the switch into place

 

Hint: Use tape to hold the battery holder in place while soldering.

Hint: Use tape to hold the battery holder in place while soldering.

Step 9

  • Insert the battery holder into the holes in the large rectangle at the end of the board with the spring end (negative terminal) near the largest suspension hole.
  • Solder these leads to the pads with the soldering iron; trim excess leads with pliers.
LED flush-mounted (best for reading, under counter light)

LED flush-mounted (best for reading, under counter light)

LED mounted facing forward (right angle--best as a flashlight)

LED mounted facing forward (right angle--best as a flashlight)

Copyright © 2013 Ears To Our World