Amazing Animated Engines!

After a busy year we are getting ready to re-launch the site with lots of fascinating projects. We love to tinker and learn from our projects. This is an amazing web site and if you have not visited we definitely recommend taking a look. It’s great tool to visualize Stirling engines, Beam engines, Wankel engines, Four Stroke engines and many more.

Animated Engines!

engines

Peltier Cell – Revisited

Sometime ago I experimented with a couple of Peltier cells that I had lying around to attempt to charge a mobile phone. It was a crude experiment and did not produce enough current. However it got me thinking about temperature differential on dissimilar metals to produce a current. I recently starting reading a book from the 19th century on magnetism and it describes the Seebeck effect in detail. It’s a curious effect and I lifted the following passage from All About Circuits:

An interesting phenomenon applied in the field of instrumentation is the Seebeck effect, which is the production of a small voltage across the length of a wire due to a difference in temperature along that wire. This effect is most easily observed and applied with a junction of two dissimilar metals in contact, each metal producing a different voltage along its length, which translates to a voltage between the two (unjoined) wire ends. Most any pair of dissimilar metals will produce a measurable voltage when their junction is heated, some combinations of metals producing more voltage per degree of temperature than others [Source all bout circuits.com]

The full article can be found here Thermocouples

As an experimenter it poses an interesting question could a portable, small form factor Thermopile stack be used to charge a mobile phone from solar power (rays)? What is a thermopile stack? It’s basically a stack of dissimilar wires in series with junctions on each sides with heat applied to one side of the junctions and the other side of the junctions connected to a heatsink. More wires in series should result in a greater voltage. It’s similar to creating a stack of Peltier cells. I will be exploring this in greater detail and posting all results here.

10 Minute Peltier Cell Mobile Charger

I had a few Peltier cells laying around and finally decided to experiment, if sufficient current could be made to flow and charge a mobile phone using a DC-DC Boost module from EBay. With an output of 5v @500mAH it should be fine to charge most mobiles. I tested it on an iPhone 4S, HTC Desire and Nokia 920 and it was charging using a AAA battery. The next stage is to attach the peltier cells to a heatsink to make sure the cells don’t get damaged by the heat. To get a higher voltage the cell needs to maintain a temperature difference i.e. hot on one side and colder on the other side, will increase the voltage.

Peltier Cells On Heat Sink

Peltier Cells On Heat Sink

Two Peltier cells were glued to a salvaged copper heat sink (from an old none-working macbook power supply) and connected in series to double the voltage from the cells. By adding more cells in series will increase the voltage. Peltier Cells can also be used as a cooler (e.g., chill drinks) by applying a voltage to them instead of heating them.

I found an old scent oil burner and placed a tea lite candle inside it and placed the cells on top. It may have been better to place the cells closer to the heat source and focus the heat directly on the cell using a matrix array of metal or ceramic tubes to distribute and focus the heat.

Heating Up!

Heating Up!

After 3-4 minutes 1.1v was output and was not enough to power the USB charger though was able to power a motor and Joule Thief. With an increased heat source, larger heat sink and additional Peltier cells 1.5v should not be too difficult to achieve. It’s a nice little experiment to expand on. You could also use the sun to heat the cell by focusing a fresnel len over the cell.

Voltage Output

Voltage Output

Running a Motor

Running a Motor

EEVblog forum post on peltier cells:

EVVblog forum – peltier cells

Radiant Energy Receiver Update

From further experimentation with the receiver, I extended the antenna length to approx 12meters and it’s currently supplying a constant 0.5V. If it’s left to charge the capacitors (rated at 63v) it’s maxing out at 70v in around 6 hours. When short circuited using crocodile clips the discharge from the capacitors output a pretty impressive spark and produced pitting in one of the clips.

Radient Energy Receiver

This is a simple and interesting circuit to experiment based on Nikola Teslas original circuit design. The circuit is a half wave rectifier connected to an antenna. The circuit ideally needs a good ground connection. Once the capacitors are charged they can be discharged into a Joule Thief circuit and power a LED for a few seconds.  Due to limited space my antenna is around 3meters vertically and requires around 15 minutes to recharge the capacitors and power the LED again.

The next stage is to modify the antenna design and create a bridge design with two vertical poles and a horizontal pole. I will post my findings in my next blog. Let us know your designs and your results too. Happy experimenting!

540x405

Fuji Joule Thief

This is an awesome video on how to create a Fuju Joule Thief. A Fuji Joule thief uses the flash circuit from a disposable Fuji camera (hence the name) and from the circuit you can power a florescent tube from a 1.5v AAA battery. Please be extremely careful if you do construct it as high voltages will be present and will give a nasty shock. Please ground yourself and ideally use surgical gloves too.

Joulify an Xbox Wireless Controller

xbox-360-controller-battery We love our Xbox though are getting tired at replacing the controller batteries. This seems like an ideal project to Joulify. It would be interesting to see how long the single AAA battery lasts when compared to a new battery. The project is still in it’s early days and when we have run more tests we will update this post.

Update: After installing the Joule Thief Battery it shorted the controller!! And has stopped working. Once we get another controller we will try again!

Joule Thief Bicycle Light Conversion

Joule Thief Kits Cycle Front LED LightI’m a fan of cycling and commute to our office around 10 miles away. One thing I’m always changing is the batteries for the front lights. So we decided to ‘jouleify it’.

Basically we replaced the original battery holder holding x4 AAA batteries and replaced with a single 1.5v AA battery and wired it to the basic Joule Thief Kit.

After a few efforts we got it working. Though we still need to get the switch working. No more buying new batteries!! Overall a big saving and another application ‘jouleified’.

The project can work equally well for rear lights too.

If you have any amazing new applications of using Joule Thief’s let us know.