Welcome to my first instructables
This is basically a glass or bottle illuminator, pressure operated & runs on 1 used (dead) AAA battery.
This idea came about one night when I have to fill up a feeding bottle for night feeding. I thought of an idea to illuminate the bottle and a little of the surroundings.
• Automatic turn on
• Minimal parts / components
• Used battery (Joule Thief circuitry)
• Made from scrap materials
After making this prototype I discovered that it turned out to be a great gift idea.
Step 1: Design
The entire piece measures 77mm (W) x 77mm (D) x 17mm (H). It's palm size and easy to carry around.
For the top surface I used a 4mm thick acrylic so that it doesn't bend when object is placed on top. The reflector is made of a 4mm & 1mm thick acrylic. Another 6mm thick acrylic is used as a wedge so that the whole reflector can fit tightly into the aluminum base.
For the base I made use of 13mm (OD) aluminum C-channel. I picked this because I had some around the house and most importantly the inner diameter of 11mm is just nice for an AAA battery.
The LED driver consists of a simple Joule Thief (JT) circuit. For those who are unfamiliar you can Google up "Joule Thief" or click this link. There are plenty of instructables related to Joule Thief. I find this circuit brilliant because it can drive a bunch of 3V LEDs with a "dead" battery. Since dead batteries are usually thrown away, this would mean I have a free source of power for my device.
Both JT circuit & a battery will fit nicely into one aluminum C-channel.
Step 2: Step 2: Tools & Materials
The tools required are simple hand tools. Dremel may be used but I prefer scoring knife for a clean & straight cut.
• Scoring knife
• Hack saw
• Snap Blade Knife
• Flat file
• Sand Paper (coarse & fine)
• Strong double sided tapes
• Super glue or PVC glue
• Soldering Iron & solder
• Cordless Drill with 3mm & 5mm drill bits
Mostly from scraps while electronic components salvaged from a broken mouse, mp3 player, & dead CFL.
Bill Of Materials:
• Acrylics - 1mm, 4mm & 6mm thick
• Aluminum C-channel, 13mm (OD), 11mm (ID)
• Aluminum foil
• Washer - 10mm
• PCB board
• 4x SMD LEDs (from MP3 player)
• 1x Tact switch (from computer mouse)
• 1x 2N2222 Transistor (or equivalent)
• 1x 1k Resistor (from some electronic board)
• 1x Small ferrite toroid (from dead CFL bulbs)
• Insulated wires (from telephone cord)
• Enamel coated wire / magnet wire (from small yellow transformer)
Step 3: Preparing the Acrylics
Take a 4mm thick acrylic and cut out 2 pieces. 77mm (W) x 77mm (D) for the top surface and 70mm (W) x 50mm (D) for the reflector.
It's good to cover the surfaces of these acrylics with masking tapes before working on it to prevent scratches.
Use a flat file to smoothen the edges of both pieces. I've also rounded the corners of the top surface.
Next, I used a 1mm thin acrylic sheet for the reflector base. Cut out a piece measuring 70mm (W) x 50mm (D).
Finally, with a 6mm thick acrylic cut out a piece measuring 70mm (W) x 11mm (D) to act as a wedge for the reflector.
Acrylic Cutting Tip:
Firstly, unless your acrylic has a layer of protective film always cover acrylic surface with masking tape. This will protect the acrylic's surface and make it easier put on markings.
Place a straight edge the acrylic and hold it down firmly with one hand. Using a scoring knife, begin by scoring a line onto your acrylic from one end to another with light pressure. Repeat it for at least 5 times. This is to mark a straight line on the acrylic. Now, flip the acrylic to the other side and you'll be able to see the scored line. Place the straight edge along the score line and score 5 times with light pressure.
You can now put the straight edge aside. This time with moderate pressure score along the line until it is noticeably deep. For a 6mm acrylic, I made scored 30 times on each side.
Finally, use a vise to clamp on the smaller section then snap it.
Step 4: Make a Reflector
To create a diffused look, I roughen the one side of the reflector with sand paper.
Next well need to make space for the LED module. On one side of the reflector cut out square piece measuring 50mm (W) x 10mm (D). Use scoring knife & hack saw to get this done.
Apply 1 narrow strip of double side tape on the right & left side of the 1mm base. Then get a piece of aluminum foil and stick it onto the 1mm base. Use the snap blade to trim off access foil.
Again with 1 narrow strip of double side tape on both sides of the 4mm reflector (Roughened side). Now sandwich together both acrylic pieces with the foil in the middle. Use a toothpick to apply thin layer of super glue or PVC glue on the sides (front, left & right).
Now we need to make some holes for the wires to run. Take the 1mm base and make a hole big enough for 2 wires to pass through. The hole need not be square but make sure it's centered. If you have a cordless drill, just drill a hole with a 6mm drill bit. Next, make a groove on the 6mm wedge. Again, the hole need not be squared. I used a hack saw to make a 'V' shaped groove then flattened it out with a flat file.
Finally, we'll need to cover all 3 sides with foil to prevent light from escaping.
Step 5: Shape the Aluminum
Using a hack saw, make 2 pieces with one measuring 77mm and another 89mm in length.
The shorter piece is used to hold the reflector. We'll leave it as it is.
We'll need to shape the longer piece to hold a battery & JT circuit.
Trim the edge of both ends then bend it 90° inwards to form a container. To make it precise and easier to bend gently score it with a hack saw. As aluminum will snap easily this is a one shot attempt.
Next get a thin piece of metal then bend the edge 90° to form an 'L' shape. Use a 3mm drill bit to make a hole for revert. This is to hold the spring terminal and to strengthen the aluminum edge.
Before reverting solder a piece of wire on to the spring. This will then connect to the switch.
I laid some duct tapes for insulation.
Step 6: Electronics
I used a JT circuit to drive my LEDs. There are many JT designs. I've tested a few on a solderless breadboard and chosen a circuit that could light up 4 LEDs and has minimal components. I've discovered that they key component is the 2N2222 transistor.
I found a bobbin type core in a CFL circuit. It is small and fits nicely into the container so I used this instead. It is advisable to test your windings on a breadboard before soldering.
The JT circuit also incorporates a positive battery terminal. It is made using a 10mm washer, soldered onto a small piece of PCB board.
The tact switch is soldered onto a piece of PCB board. Eventually, all wires will be linked here. Size of the board doesn't matter but it should be wide enough to solder all five wires here.
The LED module consist of 4 SMD LEDs that I extracted from an MP3 player. All four are connected in parallel soldered on a piece of PCB measuring 50mm (W) x 10mm (D). 2 wires will go to the switch.
I've tested different types of LEDs but I find these SMDs bright and small enough to be concealed easily.
Step 7: Assembly
All acrylic pieces are put together using some extra strong double side tapes. Before final assembly make sure you've tested all circuits including the Joule Thief module. Disassembling could damage the circuits.
Lets begin by assembling the LED module and the reflector.The LED module will fit nicely into the cut out we've made earlier. Use double side tapes to stick it in place. I used some clear tapes as insulation to prevent the LED terminals from touching, preventing short circuit. Use some heat shrink tube to hold the wires together and to double as a strain relieve. Attach the 6mm wedge to the reflector with double side tapes. Then slot the entire piece into the aluminum C-channel.
Now slot in the JT circuit into another piece of aluminum container we've made earlier. Make sure the inner part had been insulated to prevent short circuit. Stick this container onto the top surface with double side tapes.
Place the trigger switch circuit on the reflector's base. Make sure it's centered then secure it with some double side tapes. Next, solder all five wires on to the switch circuit board.
Step 8: Testing
After assembly it is time to test your creation. If you've tested your circuits before assembly it should work straight away.
First of all, install a AAA battery. It doesn't have to be a brand new battery however, for testing it's best to use a known good battery. That way if it doesn't light up, you'll know it's not because of the battery. I used one out of a remote.
Start by flipping the illuminator upside down and then press the switch. The LEDs should light up. If it doesn't then start by checking your solderings on the trigger switch circuit board with a multimeter. You could have also connected the tact switch in the wrong direction. Switch you meter to continuity mode to test the switch. It should be an open circuit between the (-) LED & (+) LED leads.
If you have got it all sorted out then turn it around with the switch on a flat surface. Place a glass on top to see if it works. Sometimes the switch is not protruding enough. To fix this, simply add another layer of double side tape on the trigger switch circuit.
I hope you find this instructables usefull and If you like it, please vote for me.
Step 9: References & Links
Here are some great instructables that I referred to while planning for my little device
(1) Joule Thiefhttps://www.instructables.com/id/Electronics-Joule-...
(2) Acrylics https://www.instructables.com/id/Workshop-Tooling