Introduction: Peltier Fan / Phone Charger
Jean Charles Athanase Peltier a 30 year old watch dealer that decides to turn physicist. His experiments lead to the technology used in this project. Worth a good Wiki read.
As a fellow 30 yr old tinker man I decided to give it a shot. Had been wanting to create air flow on top of my Rocket Mass Heater as lots of the heat rises straight up from the barrel top. As a youngin I had seen a few Peltier Fans produced for just this reason.
Very much so am I wanting this to be very aesthetically pleasing as the Rocket Mass Heater is the center of the living space.
I always keep heat sinks from past PC builds and upgrades. So that was a bulk of what I needed.
Purchased for this project.
An electric motor from radio shack the only one they had on the shelves. Rated for 1.5 voltsish
The fan blade was given to me from an RC store.
40mm X 40mm Peltier claimed to produce up to 12volts (ebay)
Mini PFM Control Step Up Booster.
From then on it was a barrage of making things fit.
Step 1: Gather All of Your Parts
I did a series of stacking the heat sinks and peltier device. To visualize where and how my fan motor would be mounted.
After some measuring I realized that if I sacrificed one of my OOAK Forge slingshot frames it would work perfectly.
Step 2: Attaching the Fan Motor
I chopped the frame at a length that the fan would be centered in the upper heatsink.
Then cut the frame where the large hole is that fits the fan. This was done so that I could smash that sliced area closed to create a clamping action on the motor.
Using a chisel to pry the opening open and slide the motor into the hole. To my slight surprise it worked really well.
Three holes were tapped into the lower heatsink. Two in the front for the slingshot frame to fasten to the sink. One in the center back for a spring that will come into play later.
Once ready to attach the frame I placed two standoffs in between the frame and the sink to help dissipate heat from the fan motor.
Step 3: Attaching the Upper Heat Sink to the Lower
My intent was to use a similar spring bar that is used to sometimes hold CPU heat sinks onto the CPU.
I found a metal scrap piece that sorta of fit. Then proceeded to sand and file until it hooked into the slingshot frames existing hole. The back end left ever so slightly lifted.
A hole was drilled in the back for a spring to fit through. I customized an existing spring to hook onto the rear screw and onto the spring bar. That was a rather painful experience and was totally bananas.
Once all was said and done it worked again surprisingly well.
Step 4: Solder All the Things
Solder the Peltier Device to the Fan Motor.
After testing I went back and added leads for testing other devices. Such as the Mini PFM Control for charging 5 volt devices. This is the device that allows you to charge items requiring 5 volts.
I used butt splice connectors that have solder in the middle and only requires a heat gun. Very nifty little thingies.
Step 5: Dry Fit
By this I mean put everything together and make sure it all fits. Do this before the thermal grease application.
Always happy to do this an learn things before I even start to think I'm done. When I did mine I found out that my fan blade struck the "spring bar". I took it apart and filed it down for the need clearance.
Step 6: Make Go and Keep Experimenting
After testing the fit of everything I then put it back together using the thermal grease between the peltier device and both heat sinks.
So, Lower Heat Sink, Grease, Peltier, Grease, Upper Heat Sink.
It works great and was relatively simple to make. I assume this can be completed in a multitude of ways. This was mine hope you enjoyed
The rocket mass heater surface in the center has reached 830 degrees so I keep it towards the edge where it is more along the lines of 500 degrees. In that area the top of the heat sink doesn't reach above 320 which is ideal as the Peltier is rated for no more than 350.
My phone recognizes that it is charging, but I feel the draw from the fan and phone is to much. A switch or other devices are to be tested.
Best of luck!