This is an instructable on how to build a pocket/portable desk fan. This being dual 5 volt fans running at 7+ volts it actually puts out quite a bit of air and is kind of loud. Extremely portable and extremely functional.
Note: This fan will only work in the open position is not meant to work closed. This is a desk fan not a handheld fan.
Build, Rate, Enjoy!!
Step 1: Prep Work - Materials
To do this project you will need some basic materials and tools. I try to use what I have lying around so you could substitute some of the materials with other stuff that you may have handy. You will need:
- Altoids Tin(Or similar tin)
- Two 5 volt Fans
- Two 3.7v Li-Ion cell phone batteries
- On/Off Switch
- Super Glue
- Electrical Tape
- Tin Snips(Wire cutters work but cuts are extremely rough)
- Pocket Knife
More specific details on materials used are in the following steps.
Step 2: Step 1 - Case Work
The first thing you want to do is cut the case to allow for the fans. I used two 50mm fans but ideally you would use 40mm fans as they will fit in the case without having to split the lid and cut the lower case. Once again I used what I had on hand. If you use 50mm fans you will have to cut the lid and only use the front and back flanges of the lid. Also the ends and back of the lower case have to be cut to allow the fans to fit down when the case is closed. Be sure to leave the tabs that hold the lid on. The last stage of case work is to make a notch for the switch or switch wires depending on what type of switch is used. I used a voltage selector switch out of an old power supply, only small switch I had on hand.
Step 3: Step 2 - Li-Ion Battery Prep
I used two 3.7v Li-Ion cell phone batteries because they are thin, powerful, and just sitting around. These particular batteries go to an LG Dare battery model number LGIP-530B, You can purchase these or similar batteries on ebay for around $3/ea including shipping! These batteries had cases that needed to be removed to have better access to the terminals. In this case the battery case is positive and the isolated terminal is ground/negative. Wire the two batteries in series for a total voltage of 7.4 volts, this is a little out of range for the fans but seems to work okay.
Step 4: Step 3 - Glue Fans and Build the Circuit
The next step is glue the two fans together and to wire everything up. I wired ground/negative side of fan to switch then switch to battery ground/negative and the fan positive side to battery positive. I ended up going back and trimming up the wire to make everything fit into the Altoids tin.
Step 5: Step 4 - Assembly
Final step is to put it all together. Remember to check fitment on everything the case will probably need some minor adjustments, mine did. Glue the front and rear flanges of tin lid to fans making sure they are properly aligned. To attach fan lid to lower tin use the existing tabs on lower tin. When assembled use a rubber band to help keeps things all together, I also kept the Altoids cut out as a fan cover.