Salvaging Parts From Burnt Out Mini-fluorescent Lamps
by Franks Instructables in Circuits > Reuse
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Salvaging Parts From Burnt Out Mini-fluorescent Lamps
Many useful electronic components can be salvaged from burnt out Mini Fluorescent Bulbs. The components are located in the lower part of the bulb. The circuit ( an AC frequency converter) takes the 50 or 60 cycle AC from the line, turn it into DC and then turn it back into high voltage, high frequency AC to excite the Mercury vapor in the bulb thus forming an arc and giving out Ultraviolet rays and in turn exciting the Phosphors (Phosphorous based electro-sensitive chemicals) coating the inside of the bulb. These Phosphors when hit with UV light, give off visible light of a color that is determined by their chemical formulation. The 2 transistors that are contained in this bulb are rugged and have can take up to 700 volts between the Collector and Emitter at 2 Amps. This means that they can be used in many high voltage driving circuits. The 200 volt electrolytic capacitors are very useful to people who restore old tube equipment as the Electrolytic Capacitors are the most frequent item that goes in old radios and audio equipment. I have put these salvaged capacitors in many old radios and have never had any problems over the years. The rest of the components are useful also but can just be added to your junk box for later use.
Obtain Burnt-out Mini Fluorescent Bulb Like This.
WARNING: THIS BULB CONTAINS MERCURY AND NEEDS TO BE DISPOSED OF PROPERLY IN APPROVED BINS AS PER YOUR LOCAL MUNICIPAL REGULATIONS. WRAP THE GLASS PART IN CLOTH OR PAPER TOWEL SO THAT YOU WILL NOT CUT YOURSELF WITH GLASS OR COME IN CONTACT WITH THE MERCURY THAT MIGHT SEEP OUT OF THE BROKEN GLASS. WORK SAFELY AT ALL TIMES! WEAR GLOVES!
Cut Along Seam With Large Tubing Cutter
Get a tubing cutter that cuts at least 2 1/2 copper tubing. Wrap a cloth or paper towel around glass part of bulb and cut the seam in white plastic part of base using back and forth motion to completely seperate top and bottom of bulb.
Gently Separate Top and Bottom of Assembly
When you have cut through plastic part of fluorescent bulb assembly with tubing cutter, use side cutters to cut circuit board from wires that connect it to glass bulb part and base. Glass part and rag should be disposed of in matter approved in your local juristiction for the disposal of Fluorescent bulbs. Even if glass part doesn't break, assume it is contaminated with mercury and dispose of it anyway. Don't re-use it!
Gently Unsolder All Electronic Components From Circuit Board.
Unsolder electronic components from circuit board using mini hemostat. (Obtainable from electronics supply stores). Grab base of component wires with hemostat on side opposite to soldered side and gently pry up while applying heat from low wattage soldering iron. This will prevent heat from damaging heat sensitive parts like transistors and diodes while giving you leverage to pry the component out. I was able to salvage 24 components from just 1 burnt out mini fluorescent bulb. Bigger ones have more and heavier duty components. Here is a list of what is in the picture:
3 Inductors
6 Non-polarized Capacitors: (2) .05 uF, (1) .001 uF, (1) .0027 uF, (1) .048 uF
5 Resistors: (3) 470K (2) 15 Ohm
2 Electrolytic Capacitors: 200 volt, 15 uF
6 Rectifier Diodes: 1N4007
1 Diac
2 Transistor: E13003: NPN Power Transistors