Build Your No-Battery Remote

1. Build the Faraday Generator

The system consists of 4 main components:
1. Infrared remote control device
2. Faraday voltage generator
3. Charge storage component
4. Voltage regulator

Shown here is the schematic of the Faraday voltage generator, the charge storage capacitor (capacitor C1 consisting of two 4700µF/16V capacitors in parallel), and the voltage regulator circuit based on a low dropout (LDO) regulator.
1a. Groove the tube (optional). I chose a 4" diameter Perspex acrylic tube with 3" internal diameter. The length of the tube is approximately 6". You'll need to machine out a 1.5mm-deep groove into the tube, along about 2" of the tube's length. The groove is where you'll wrap the wire. If you don't have access to a lathe with which to cut a groove, the wire can be wound directly onto the plain acrylic tubing. Just use plenty of masking tape to ensure the wire doesn't unwind.
1b. Wind the wire. Fill the groove with 1,400 turns of 36 SWG enameled copper wire. If you have a coil-winding machine, it will be a lot easier. If not, you can improvise with a power drill and a helper: use the drill to slowly rotate the tube while a friend, wearing work gloves, feeds the wire to you. Leave about 6" of wire free on each end. When you're done, cover the wire coil with masking tape, and use 1mm-diameter heat-shrink tubing to cover the 2 free ends of the wire. If you didn't groove the tube, just wind the copper wire directly onto the plain acrylic tube. Be sure to use plenty of masking tape to ensure that the wire doesn't unwind.
1c. Place the magnets inside the Faraday generator tube, stacking all 4 to make 1 big magnet. Using a hot glue gun, seal the ends with 2 pieces of perfboard, cut and filed in circular shape. To make it more permanent, use a 2-part epoxy.

2. Prepare the TV Remote

2a. Remove the batteries from the remote control (forever!) and file down the entire battery compartment to remove all extrusions, as shown. Also file a notch in the side of the battery compartment and the compartment cover, so you can run the wires from the Faraday generator inside.


NOTE: You'll need to take the guts of the remote out. Just set them aside.


2b. Assemble the components from the circuit diagram (capacitors, diodes, and LDO voltage regulator) on a perfboard as shown here. You can test the continuity with a multimeter.


2c. Solder the output of the voltage regulator circuit onto 2 hookup wires (extreme right in the photograph) on one end of the perfboard. You'll eventually solder these hookup wires to the battery terminals of the remote control.
2d. Connect the Faraday generator. First solder 2 hookup wires in the middle of the perfboard to the input of the bridge rectifier (cathodes of diodes D3 and D4, respectively, in the circuit diagram). Then solder the wires from the Faraday generator to these hookup wires.


2e. Reassemble the TV remote, and fit the circuit board inside the battery compartment as shown.


2f. On the remote control's original circuit board, cut down the battery terminals so that they can be soldered to the voltage regulator circuit board. Solder them to your voltage regulator output wires.


2g. Tie the Faraday generator temporarily to the TV remote body using cable ties, and shoot more hot glue between the remote and the Faraday tube. If you want to glue them more permanently, use a 2-part epoxy such as Araldite or J-B Weld's J-B Kwik epoxy. Now you're ready to shake!






By Dhananjay V. Gadre. published in Make Magazine, Volume 12.