German Perilla has created a lovely demonstration on how to modify a LED flashlight and make it into a high powered microscope light that can be plugged into an electrical outlet. Comparable to, but much cheaper than, fiber optic lights. Do it!

1. How to Make a
Microscope
Light
Pictures and Layout by German Perilla
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2. This is the original document regarding converting flashlights to microscope lights. The power point that follows expands on those ideas
All:
As part of building up our lab with scant money for equipment, I have been frustrated about the cost of high quality microscope lights. Even
old fashioned illuminators now cost well over $200.00 and still deliver sub par light compared to that from fiber optic. Recently, I was in a
camping store and was looking at the LED miniflashlights. I noticed that there were now some high intensity 3 watt varieties and picked up a
Gerber LX3.0 (about $50.00) to see if would work as a microscope light. I was impressed with how much light it put out for such a small object
(7.5" X ~1" in diameter at the head). At home I tried it out and it blew away even my inexpensive fiber optic (ecolight).
At the office I found that the flashlight fit very nicely into the standard Bausch and Lomb stand's illuminator hole; a little adjusting up and
down and I had all the illumination I wanted.
After a while I noticed that the light dimmed as the batteries drained down. I could convert to recharchables, but after reading more about how
these particular flashlights work:
http://candlepowerforums.com/vb/index.php?
(this is an amazing web site, populated by fanatical flashlight nerds who chat all day about the technical specs of every flashlight known to
mankind, check out the LED forum)
I realized that they had a long battery life, but that they did not hold the voltage steady and that light would dim relatively quickly.
The solution was to connect it to house current.
I had been saving wall cube transformers for years, just in case they would come in handy and it turns out that I had a couple that would
output around the 4.5V the flashlight liked. According to the experts the LED bulbs are pretty tough so you could likely run them up to maybe
6V without shaving too much off their life.
Make sure that the wall cube converts AC 120V (input) to somewhere around 4.5V DC and not to 4.5V AC....some convert to the proper voltage
but in AC. I didn't look closely the first time I tried this and I ran the light on AC, which worked OK, but the light shimmied around and was
distracting.
To do the conversion take out the batteries and run a wire down to the bottom of the flashlight. I used a dowel to which I added a tiny screw
to one end and then attached a wire to that screw and tightened it. Be careful to not let any of the wire touch the wall of the flashlight or it will
create a short. I then taped the wire to the dowel and ran the whole thing to the bottom. For the return, I ground off some of the
nonconductive anodized finish, and simply taped the end of another wire to the body. I cut the end of the wall cube off and attached the wires
to wires coming off of the light. If your first try doesn't work then switch the wires as the polarity may be wrong (this is not supposed to be
healthy for the LED, but mine survived). You can then put a switch in the line if you want, or simply plug and unplug the wall cube.
I imagine that price and variety will lower the price on these flashlights soon too.
Have fun.
sam
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3. Parts and Tools Required to Make a
Microscope Flashlight Holder (2008 Prices)
One Microphone stand adapter
Where to find it: RadioShack
Price $6.29
Reference 3300372
Joseph F. Metzger, Jr’s Idea
2 ½ pound weight
Where to find it: Sports Authority
Price $2.48
Reference 18694314
3

4. Parts and Tools Required to Make a
Microscope Flashlight Holder
A B
½’ 45°Bell end elbow
Where to find it: Home Depot
Price $0.88
Reference UA7ADB-CTN(25)
Saw
Where to find it: Home Depot
Price $3.50
4

5. Procedure to Build the Flashlight Holder
Cut part “B” to give the height you need for
your microscope
Insert The shorter part “B” into part “A”
Glue is not necessary
Sand to remove all the markings
5

6. Procedure to Assemble the Light Holder
The microphone holder has a
threaded mount.
Screw the microphone holder into the
curved tube as shown (you may
need to use a vice clamp to hold the
tube during this procedure). Also,
you may want to heat the tube by
placing it very hot water for a minute
or two to make it softer.
Make sure that the microphone
adapter aligns as shown in the
picture.
Finally, insert the thick part of the
stand into the weight hole, it will fit
perfectly and will provide the right
stability to the stand
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7. Parts and Tools Required for the Electrical
Connection
4.5 Volts Mini AC to DC Adapter
Where to find it: RadioShack
Price $ 37.67
Reference 2731760
Hobby Leads Assay
Where to find it: RadioShack
Price $3.39
Reference 2731742
7

8. Parts and Tools Required for the Electrical
Connection
A 4.5 volts or 5 volts transformer will work,
be sure that it is an AC to DC transformer
not an AC to AC transformer
8

9. Parts and Tools Required for the Electrical
Connection
Cord Switch
Where to find it: Home Depot
Price $3.56
Reference 030721705007
Polyolefin Heat Shrink Tubing
Where to find it: Home Depot
Price $1.97
9

10. Parts and Tools Required for the Electrical
Connection
I used masking tape, but any tape will do
Any sharp blade will work
10

11. Parts and Tools Required for the Electrical
Connection
Braided copper 50 centimeters
This is easy to roll
Or you can use any copper wire
gauge 16 to gauge 14
Electric cable gauge 24
The gauge 24 is very important because it
will allow the insertion of the connecting
devise later
Need 30 centimeters
11

12. Parts and Tools Required for the Electrical
Connection
Soldering Iron
Price $17.96
Electric solder Lead free rosin core
Price $5.00
Where to find it: Home Depot
Clippers
12

13. Parts and Tools Required for the Electrical
Connection
Phillips Screw Driver
Drill bit 5/32
Drill bit 5/32 HS 961 (Long)
Drill bit 3/16
13

14. Parts and Tools Required for the Electrical
Connection
Or Drill Heat gun
Drill press
14

15. Parts and Tools Required for the Electrical
Connection
3/8 x 36 Oak Dowel About one centimeter in diameter
Where to find it: Home Depot
Price: $2.00
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16. Parts and Tools Required for the Electrical
Connection
Gerber LX 3.0 LED Flashlight
Where to find it: REI
Reference 7202570011
Price $36.57
16

17. Procedure to Make Contacts
Tools:
Final Product
Soldering Iron
Solder
Piece of board
Measure 6 centimeters of the braided copper
strip, you will need two contacts (+, -) so
make two of these.
Bend it 90° as shown in the picture
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18. Procedure to Make the Contacts
Coil the 6 cm of the copper wire from the
center of the bend you just made to the
end.
This is how the copper wire coil
should look
18

19. Procedure to Make the Contacts
Drill a hole in a board to hold the wire as
shown. Use a 5/32 bit.
19

20. Procedure to Make the Contacts
Apply the solder and then smooth and spread it over the coiled cupper
Two of these contacts are needed
Cut the contacts so that they measure
about one inch
20

21. Procedure to Make the Electrical Connection
Cut the Dowel to measure
exactly 15 centimeters, the
length of three AA batteries
Tools:
Drill press
Drill bit 3/16
Tape
Mark the center of the dowel, 7.5
centimeters from either end
Place a piece of tape 8 millimeters
from the tip of the drill bit, this
visual guide will let you know
when to stop drilling
Drill an 8mm hole in the middle of
the dowel
21

22. Procedure to Make the Electrical Connection
Tools:
Drill Press
Drill bit 5/32
Drill bit 5/32 HS 961 (long one)
This is the most difficult part of the procedure
Use the shorter drill bit 5/32
Place the dowel as shown in the picture make sure it is
perpendicular and in perfect alignment with the drill bit
Hold it with you hand
Drill a one inch hole as a guide for the longer bit
Exchange drill bits (Place Drill bit 5/32 HS 961 (long
one)
Drill the entire length of the dowel (15 cm)
22

23. Procedure to Make the Electrical Connection
The Dowel should look as shown in the pictures
You should have access to either end of the
dowel from the center hole
23

24. Procedure to Make the Electrical Connection
To turn on the Gerber LX 3.0 Led
flashlight you have to tighten (rotate
clockwise) the cap until batteries
make contact with the led
To determine where to open the
hole on the flashlight, so that it
aligns with the middle hole of the
dowel I placed the two contacts I
made in the dowel, placed the dowel
inside the flash light, pushed until
contact was made and took the
measurement
Tools:
Drill Press
3/32 drill bit
Open a hole in the flash light at
exactly 6.8 cm as shown in the
picture
24

25. Procedure to Make the Electrical Connection
25

26. Procedure to Make the Electrical Connection
Tools:
Clippers
Blade
Cut 30cm of the 24 gauge cable
Split them apart
One will be smooth, the other will have
ridges or some lines printed along the
outer border
26

27. Procedure to Make the Electrical Connection
Introduce both cables thought the hole in the
flashlight until you have about one inch left out
side the flashlight, refer to the pictures
Strip about one inch from the long end of each
of the cables and twist the individual strands of
copper wire together so that if forms a single
wire
27

28. Procedure to Make the Electrical Connection
Place the dowel parallel to the flashlight, this is
the direction in which it will be introduced into
the flashlight
Take the smooth cable and proceed as
indicated in the picture until the cable comes
out
Place a piece of tape to keep it in place
28

29. Procedure to Make the Electrical Connection
Take the cable with the ridges and
repeat the procedure until the cable
comes out on the opposite side
(refer to the picture)
Remove the tape and make sure that
you have enough lag in the cable, so
you are able to introduce the dowel
into the flashlight. (just measure the
distance)
29

30. Procedure to Make the Electrical Connection
Tools:
Polyolefin Heat Shrink Tubing 1/8
Heat gun
Soldering iron solder
 Cut two equal parts of the 1/8
Polyolefin Shrink Tubing
 Insert one half of the shrink
tubing in the cable
 Twist together the terminal and
cable ends
 Optional: Apply solder to secure
the jointed ends
 Pull the shrink tubing as shown
in the picture
 Apply heat with the heat gun
until it shrinks around the joint
 Repeat the procedure at the
other end
30

31. Procedure to Make the Electrical Connection
Gently pull the cables until both terminals
are against the tips of the dowel
Refer to the pictures
+
-
The ridged cable corresponds to the
positive end of the batteries, and thus the
smooth cable corresponds to the negative
end of the batteries
With one hand gently push the dowel into
the flashlight
With other hand gently pull the cable that
- comes out of the drilled hole, until every
thing is in place
31

32. Procedure to Make the Electrical Connection
The pictures indicate how it should look
32

33. Procedure to Make the Electrical Connection
The power adapter has two ends one
that plugs to the wall, and one that
plugs to the appliance
 Cut the end that plugs to the
appliance
 Identify the two ridged cables
 Optional Insert a piece of the ¼
shrinking tubing
 Split about 15 centimeters of the
cable
 Cut the 1/8 shrink tubing in half
and insert on each end as shown in
the picture
33

34. Procedure to Make the Electrical Connection
Optional: Insert the 3/16 shrink tubing
as indicated in the picture onto the
flashlight wires. This will provide
support to the thin cables
Strip about one inch of each end of the
four cables (refer to the picture)
34

35. Procedure
Join the ends making sure that the two ridged
cables are join together and the two smooth
ends are joined together
Apply solder to the joins to make a
better connection
Place the 1/8 shrink tubing over each of the
joins
Apply heat with the heat gun until properly
fastened
35

36. Procedure to Make the Electrical Connection
Use the heat gun to shrink the 3/16
tubing that cover the cables that come
out of the flashlight
Move the ¼ shrinking tubing over the
joined cables
Apply heat with the heating gun
36

37. Procedure to Make the Electrical Connection
Decide where you are going to install the switch
I did it about 40 cm away from the flashlight
 Open the switch
 At the distance where you decided the switch
is going to be, split the cable using a sharp blade
(about 2 cm)
 Cut the smooth cable in the middle and place it
in the switch as indicated in the picture
 Replace the other half of the switch and press
firmly
 Fasten the nut until the whole unit is
assembled properly
 Place the flashlight in the microphone holder
 Plug the transformer into the wall
 Turn on the switch
 And you should have a working microscope
light
37

38. End Product
38

39. This is the change I experienced !!!
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40.  German Perilla
Email: gperilla@gmu.edu
Cell 703 307 6770
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