Desk Lamp 02

Overview

This is an elaboration on Desk Lamp 01. See that project for basic components and assembly. This page only includes the additional elements of the second lamp.

I wanted a lamp for my electronics bench. In addition to the basic lamp function I added an exhaust fan to pull soldering fumes away and a USB jack to provide 5 volt power for projects.

lamp02_1
lamp02_2
lamp02_4
lamp02_3

lamp02_5

Lamp Materials

This lamp uses many of the same materials as Desk Lamp 01. In addition it uses:

  • Two of the 4 led cool white strips (G20003) from Electronic Goldmine ($5) instead of the single LED strip used on the first lamp.
  • A second toggle switch for the fan.
  • A 60mm muffin fan designed for cooling computers (about $4).
  • A 12v male USB type A jack with wires, designed for automotive installation. This can be found as a “DC DC Converter Module 12V To 5V With USB Output Power Adapter 15W” for about $7 on Ebay.
  • A 3D printed lamp head. This is essentially a box with a 60mm hole for the fan, a couple of angled standoffs for the LED strips to mount to and bolt holes designed in. A found box of the appropriate size could certainly be used instead.
  • Four bolts with lock washers and nuts.

The 12v AC adapter used for this lamp needs to have enough power to handle the fan and the USB power outlet as well as the LEDs. I used a 1.25A unit, which does the job well.

Wiring is straightforward. The LED strips are wired to one switch as in the first desk lamp. The fan is wired to the other switch.

The switches and USB jack are mounted into the almond can in the same manner as the first desk lamp. However there were two complications:

  1. The USB jack requires a rectangular hole, which is difficult to cut with square corners. To secure the jack and make sure there would be no leaks when the epoxy is poured I surrounded both sides of the hole with a thick collar of epoxy putty and allowed it to cure before inverting the can for the next step.
  2. I made a near fatal error and did not seal the switches inside the can sufficiently to prevent epoxy intrusion. As a result one of the switches became frozen in place with cured epoxy. I had to cut the can open and remove the switches. Fortunately there was enough exposed wiring to solder in new switches attached to a patch of black plastic. It doesn’t look nice, but it works. Seal your switches well before pouring epoxy over them!

I have found this unit extremely useful in daily operation. The light helps when working with small electronic components. The fan does a fine job of pulling soldering smoke and fumes away from my nose. You could certainly add a square of charcoal filter material if you would like to something closer to a proper fume extractor. The USB power is very handy. With the addition of a purchased or made USB to header pin cable it provides a very convenient source of 5 volt power to breadboards and individual components. The only shortcoming on this project is that the 8mm gooseneck is slightly too weak for the amount of weight it is suspending and can droop at certain angles. If I were to start this one over I would use 12mm or thicker gooseneck.

 

bill@robot50.net