Illuminator Pill Kit

Luxeon LED with DC/DC

Please Visit the New Conversion Kit Page Here

Using the complete ILL PILL Integral Luxeon LED 

Typical applications for modifying small 2AA flashlights require the assembled converter to be used in place of the original bulb socket assembly in commonly available flashlights such as the Brinkmann Legend or MagLite MiniMag. 

MiniMag conversion instructions:

Installing the lens and o-ring:

Remove the flashlight head and unscrew the front bezel. Remove the reflector and drop in the lens and then place the o-ring on top of it. Install the bezel (leave in the front window) and tighten. 

 
Disassembling the flashlight:

Remove the bulb and pry off the top of the bulb switch socket, and push the plastic assembly inside out the end of the battery tube.

Drop the ILL Pill in to the battery tube, Luxeon end first. Install 2 AA batteries and install the tail cap. The Pill should be lit up nice and bright.

Screw on the head assembly and check for proper on/off operation.

That's it, you're done. Enjoy your new light.......

Do-It-Yourself Kit Assembly Instructions

The Illuminator Pill Kit

First, for the record, this is not an elegant design, and perhaps breaks nearly all the good engineering practices possible. It is however, the cheapest voltage boost circuit known that can drive a Luxeon brightly, and is very forgiving. Forgiving in the fact that it will tolerate both open circuit and short circuit operation. And with the Ill Pill Kit components, can be built into a circuit package that will replace the incandescent bulb socket in popular 2AA flashlights to transform them into bright LED flashlights.

This kit is intended for use with 1 watt Batwing (low dome) Luxeon LEDs and NX05 optic. It can also be used with 1 and 3 watt Lambertian (high dome) Luxeon LEDs, but results with the NX05 lens can make for difficult beam alignment. Use with high dome Luxeons and reflectors require advanced modification to the flashlight and reflector. Instructions will be added at a later date.

For those interested in just how this circuit functions, including the basics of how all DC/DC boost circuits work, there is a technical discussion following the instructions. For those not interested in the details of how this circuit works, and just want to get started building the kit, here are the instructions:
First, take inventory of the kit. You should have two circuit cards, IC, wire and toroid. 

You will need to supply a Luxeon LED for use with these five parts to make the Illuminator Pill.
Please read through all the instructions so you are familiar with the steps before beginning.
  • Before starting construction, test fit the two circuit cards into your flashlight battery tube. File the circuit card edges as required so the boards drop freely into the battery tube.
Step 1. Soldering the IC

NOTE: If your kit came with the IC already soldered in place, skip to Step 2
Position the IC on the circuit card as shown in the drawing. It may be beneficial to use a small drop of epoxy under the chip to keep it in place during soldering. If you use epoxy, use only a very, very small drop; you don't want it oozing out from under the chip and interfering with the solder flow.

TIP: Before doing any soldering, you can insure there are no "wisker" shorts on the circuit card by checking for isolation between the three areas of the circuit card. Set your meter to measure resistance and check between GND and V in, between GND and V out, and between V in and V out. They should all be isolated from one another (measure infinite resistance).
It is usually easiest to solder the lower right pin (pin 5) first, which will anchor the IC in position for soldering the remaining pins. Work very fast; do not apply heat for more than one second at a time, and allow the circuit board to cool between soldering pins. If possible, place the circuit card on a piece of aluminum or other metal surface to help dissipate the heat. Solder all the IC pins, letting things cool off before moving on to the next pin. Check your work; you may need to use alcohol to clean any flux residue off to verify that there are no solder bridges or bad solder joints.
Solder all the IC pins, letting things cool off before moving on to the next pin. Check your work; you may need to use alcohol to clean any flux residue off to verify that there are no solder bridges or bad solder joints.
Step 2. Mounting the Emitter
Straighten and bend the emitter leads backwards as shown in the photo. Test fit the emitter leads in the holes of the circuit card to make sure they fit ok; trim width as necessary. Note that the hole is counter sunk for the positive Luxeon lead (the one with the tab next to it) to prevent the lead from shorting to the top side copper surface.
Mix a small amount of thermal epoxy such as Artic Allumina or Artic Silver for use in mounting the emitter. Apply a thin coat to the back side of the emitter and observing polarity as shown in the photo, insert the leads through the holes in the circuit card. Do not use too much epoxy, you don't want a bunch of epoxy oozing out from under the emitter, as you will need to solder close to the Luxeon body later. 
Bend the leads outwards to ensure the emitter will not fall back out. Check centering, and adjust the emitter position until it is exactly centered on the board.
Emitter Centering TIP -
Drop the circuit card into the battery tube, emitter end first. Since the pill is not complete, you will need to add something to take up the difference in thickness with the two batteries. Use a piece of paper towel, or other such substance about 1/4" thick, insert it into the battery tube after the circuit card. Next, insert two AA cells and install the tail cap. As a good rule of thumb, since we don't want any electrons flowing yet, insert the first battery negative end first (backwards), and the second battery positive end first. This will insure no power can flow.
Now, remove the front bezel and window from the head, and screw the battery tube into the head. Hold the head stationary, and screw the battery tube into it a few turns. Now, screw the battery tube back and forth while looking into the head at the emitter. If it is not perfectly centered, you should be able to see the offset when the emitter rotates and make adjustments. When you get the emitter positioned so that it appears to rotate without any offset, it will be perfectly centered. Set this aside for at least 30 minutes to allow the epoxy to set up.
Step 3. Making the Coil
Uncurl and straighten the supplied wire being careful not to kink the wire. Leave approximately 1 inch in length and begin wrapping the wire around the toroid. Do not allow the wraps to cross, the wire should form a continuous coil around the toroid.
Depending on how tightly you wrap the wire, you should have about 38 turns when the coil is complete, and about 1.5 inch lead length left over. Don't sweat it if you end up with 36 or 40 turns, it's not that critical, but the lead length is critical. If necessary, sacrifice a turn to get the proper lead length.
Step 4. Soldering the Luxeon cathode (negative lead)
After the thermal epoxy has set up, with the LED board still in the battery tube, remove the head and set it aside. Clamp the battery tube to prevent movement during soldering, and carefully solder the negative lead of the Luxeon to the top of the circuit card as shown. If you just can't get the solder to take, or your iron tip is too large to solder the lead with the circuit board in the battery tube, follow the alternate soldering instructions below.
Alternate Luxeon negative lead soldering instructions

Remove the LED circuit card from the battery tube and secure it in a vise or clamp so it won't move around while soldering. Observing the one second heat rule, solder the negative lead of the Luxeon to the top of the circuit card. File off any excess solder from the rim area as shown in the photo. Please note that the filings will contain lead from the solder, and should be carefully cleaned up and discarded to prevent inhalation or spreading contamination.
Step 5. Pre-assembling the Pill
Form and trim the coil leads as shown in the photo. Test fit as shown to insure proper lengths.
Tin the coil leads as shown; the enamel need not be removed from the wire as it will burn off when heat is applied during tinning.
Using no more than one second in heating at a time, solder the coil leads and Luxeon leads to the circuit card. When completed, it should look like the photo.
Again, using no more than one second in heating at a time, Solder the Luxeon negative lead to the back side of the circuit card.

Locate the anode (+) circuit card and solder the coil lead to it as shown in the photo. It is  helpful to use something to hold the circuit card stationary during the soldering process. Leave at least 1/2 inch of wire length to the contact board. Try and form a smooth low dome of solder as this will be the + battery contact when the Pill is complete.
Step 6. Pre-testing the Pill
All the components are now in place so it's a good practice to test the Pill at this point, as it will be impossible to correct any problems after final assembly. Use two AA cells to test the pill as shown. Negative to the top of the LED circuit card, and positive to the anode contact board. The Luxeon should light up nice and bright (do not operate it like this for more than a couple seconds to prevent overheating).  You should be seeing spots at this point. If not, carefully review the instructions and check for solder bridges or bad solder joints to correct any problems.
Step 7. Final Assembly
Pre-form the Pill as shown in the photo. Check to make sure the coil leads are not touching each other, or any part of the circuit board.
Carefully fold back the + contact board and apply a drop of 5 minute epoxy to the inside and top of the coil as shown. Do not use too much epoxy. If epoxy oozes out to the edges of the Pill it could end up being glued in the battery tube (bad).
Carefully fold the + contact board back on top of the coil as shown and insert into the battery tube. 
Insert two AA cells and install the tail cap. Again, we don't want any electrons flowing, so insert the first battery backwards (negative end first) and second one normally (+ end first).
Now, monitor the left over epoxy you just mixed up. When it just sets up solid, remove the batteries and Pill from the battery tube (you may have to blow into the battery tube top to get the Pill to come out). Inspect the Pill for alignment. If it is leaning to one side, carefully straighten the anode board to be parallel with the LED circuit board. The epoxy should have enough elasticity still to allow the adjustment to be made. It may flex back out of alignment and you may have to repeat several times to get everything squared up.
Once the boards are aligned properly, back fill the inside of the Pill with more 5 minute epoxy. Use a tooth pick to apply the epoxy, being careful not to apply too much. It's better to not apply enough and have to apply a second coat than applying too much. When the proper amount of epoxy is used, it should look like the Pill in the photo. Let the epoxy set up for 30 minutes minimum so it's good and hard.
Test fit the pill into the battery tube. Do not force it into the battery tube! If it does not slide right in with no more than the weight of the batteries pushing it, file the edges of the Pill down until it fits properly.

Your Ill Pill is now completed and ready for service. Wasn't that easy?
Illuminator Pill Technical Discussion -
Before going into the particulars of this design, first let's discuss basic DC/DC theory of operation.

Refer to the drawing for this part of the discussion. When the switch is closed, current flows through the coil to ground, and a magnetic field begins to build and a negative voltage is generated. If the switch is kept closed, and voltage is applied long enough, eventually the magnetic field reaches it maximum possible value; this is called saturation, and any further current through the coil flows without increasing the magnetic field density (wasted energy).

When the switch is opened, the magnetic field begins to collapse and generates a positive voltage and current out of the coil. Since this generated voltage is in series with the battery voltage, the output of the circuit is the battery voltage plus the voltage generated by the collapsing field in the coil. Typical duration of the magnetic field collapse is around 10 microseconds. Since the charge/discharge cycle of the coil (inductor) is relatively short in duration, to get any useful voltage boost benefit from this cycle requires that it be repeated many thousands of times per second. That's where switching ICs come into play.

Here is the heart of this circuit, the MC34063A Switching Regulator. This IC comes in the SO-8 surface mount device (SMD) package, and has a 1.5 Amp rated output switch transistor. The SO-8 SMD package is large enough that it can be soldered with a fine tip on a regular soldering iron. Smaller SMD packages will require the use of solder paste and a hot air tip soldering iron to solder them. But with this larger SO-8 package, it is possible to solder with an ordinary iron with little trouble.

Here's a link to the MC34063A data sheet <link>
Here is a generic schematic of how the MC34063A should be used, and what the different components do in the circuit:
And here is a schematic of how the ILLPILL circuit works, and some comments:

Note that the ILLPILL circuit ignores all the technical datasheet formulas, engineering practices, and just basically breaks all the rules, including operation well below the IC minimum operating voltage. This simple circuit relies on the IC internal limiting circuitry to limit maximum switch current, and allows the oscillator to run at the default maximum frequency without a timing capacitor. Also absent is any external feed back for current or voltage control, so the IC is basically running wide open. Also, because there is no output capacitor, no output diode is required either. The LED is being driven in pulse mode, but at such high frequency that the human eye cannot perceive any flicker. The circuit will operate down to about 1.5 to 1.6 volts (0.75V to 0.8V per cell), which is perfect for protecting NiMh/NiCd cells from damage by being discharged too deeply.
Because of how this circuit operates, performance may vary from IC to IC; that is some chips may perform better than others.

Typical pulse mode output for this converter is equivalent to 350 - 500mA, varying depending on Luxeon vfd. A voltage BIN K Luxeon may draw only 350ma while a BIN H Luxeon may draw up to 500ma. 

The easiest thing you can do to experiment with this circuit is to vary the number of turns and wire gauge in the inductor. Also, different toroid cores can also alter the performance. Another area to experiment with is adding a timing capacitor to the circuit which will alter the operating frequency and the duty cycle to some extent. So, don't be afraid to experiment with this circuit because it's hard to kill it, and even has a built in thermal limiting circuit if things do get too hot.

Using this IC with higher voltages: This circuit works well in the 3V to 4.5V range, but use with higher voltages will most likely require following those design and engineering principles laid out in the technical data sheet that were disregarded for this simple circuit. Doing so will require adding more components, and you may want to consider that there are better switching ICs available before expending a lot of design effort working with this chip. Also, it's large SO-8 package doesn't leave a lot of room for more components on small circuit boards.

History of the ILL PILL - This circuit was first built and tested in late 2001, and a very similar circuit was used to power the first Illuminator flashlights. The ILL PILL as a self contained unit was first built in early 2002 and reviewed by Craig at the LEDMuseum around June 2002. 

2AA flashlight EZ LED Mod (ILL PILL):

General notes about the modification:

This modification can be used in many 2AA cell aluminum flashlights. It has been tested in Brinkmann Legend and MiniMag  flashlights. Suitability for use in other flashlights depends on the construction of the particular flashlight. Under no circumstances should this modification be used in other than aluminum or other metal flashlights because it relies on the heat transfer from the converter to the metal flashlight body. Plastic flashlights are not suitable for use with this.

The ILL Pill uses the copper clad circuit card that makes up the top of the inverter circuit as a heatsink. While this is a minimal heatsink, not normally recommended for use with Luxeon LEDs, in this particular modification the thermal path from the Luxeon through the copper cladding to the flashlight battery tube lip is so short that adequate cooling is maintained. 

The twist on/off operation of the original MiniMag is preserved in this modification by using the Luxeon lens to push back the ILL Pill, breaking it's negative contact to the battery tube lip. Because the lens pushes against the Luxeon LED itself to perform the turn off function, it is important to not over tighten the flashlight head and damage the Luxeon. Use just enough force to insure the light is turned completely off.

It is also important when turning on the light to ensure the head is turned slightly past the point where light is first seen to insure the converter heatsink is firmly in contact with the battery tube lip for proper heat transfer.

Use of lithium batteries in this modification is not recommended due to the minimal heatsink design. 

Use in AA cell flashlights with more than 2AA cells is not recommended.

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* All flashlights are modified retail flashlights. Original manufacturer is not associated with after market modifications. Direct all correspondence to lambda@mchsi.com.