This instructable shows how to create microwave powered holiday lights for inside your microwave oven using the RFD102A Wireless Energy Harvesting Module.
Step 1: Materials
For this project you will need:
RFD102A RF-DC Converter Module $12 each available from http://www.rfdiagnostics.com/product/rfd102a/
Red or Green Kingbright Surface Mount LED: APT1608EC(red) APT1608SGC (green). These are available by request from RF Diagnostics when purchasing an RFD102A module.
Solder paste or solder
Fine Tipped Soldering Iron
A magnifying glass or a microscope helps w/ assembly.
Step 2: Assembly Instructions
1. Put two small dots of solder paste onto the module on the left two pins as shown.
2. Place the LED diode on the module so the triangle/arrow of the diode is pointing to the ground of the module (pin 8) and the flat side of the triangle is on pin 1 of the module. This is the DC output of the module.
3. Solder carefully and quickly while holding the LED with tweezers to make sure it doesn't move. Minimize the time spent soldering to prevent damage to the RFD102A module's internal components.
Your microwave light is ready to use!
Step 3: Put the Module+LED on the Tray in the Microwave
Next, put the assembled module/LED onto the tray in the microwave with whatever you would like to heat up. The microwave energy inside the oven gets picked up by the module pin 4 (RF Input) and is converted to a DC voltage out of pin 1. Since the module is very small relative to a wavelength (7mm vs 30mm for a wavelength), it doesn't pick up enough energy to spark or arc compared to leaving a teaspoon in the microwave while it's running.
In this picture are three different modules: RED, GREEN & COMBO(R+G). The combo LED doesn't show green very well because red lights up brighter than green. One fun project would be to add small surface mount resistor to the red LED to drop it's brightness so you could see both green and red from the same module.
Please note at the time of writing this I haven't tried putting the module higher in the chamber. There may be much more power available in the middle of the microwave and it could fry this module. Do this at your own risk. I can't be held responsible if this damages your microwave oven or starts a fire. I have had a module in there for many hours on the floor of the microwave with no problems and it still lights up.