Monthly Archives: July 2010
Solar power

Since a few days my solarpanels are finally mounted on the roof and conected to the batterys! It is a 24V 6x190Wp solar installation.

The power is stored in two 90 Ah batterys by a simple linear voltage regulator.

240V AC is generated by the big box at the top, a 1200W Sinus Inverter.

12V DC is generated by the small circuit in the middle which is a variable DC converter for input voltages up to 24 V at 2A, which I found lying around. I did some vodoo to it to get more than 2A at the moment it is secured at 5A, and delivers 2A without getting warm.

The installation is able to charge my batterys with 10 A on a clouded sky. Now during summer days I can power my Laptops 24 hours a day and even use a vacuum cleaner with it.

Watch Gallery!

The Gangway

On monday I need some experience, so I sawed a gateway between the box and the topsleeper of the drivers cabin of my truck, with a pad saw:

My truck has a modern tilt cab, and a removeable box, so the gateway must be removeable, too. So I decided to solve that later and taped some bin bags around the gate. Unfortunately my tanktape was empty after I taped half of the bags so I had to use gaffer….

Of course this goes wrong when it starts raining on friday:

So I have to do some emergency building. The plan was to build two frames for each side of the gate to mount a tunnel made from lorry tarpaulin between.

I used some aluminium profile for the frames:

After the production of the frame I started to make a pattern for the tunnel on the tarp:

I sewed it with an old Singer sewing machine I got from my grandmother. The tunnels in the corner are for elastic bands which should fix the tunnel to the frames.

mounting the frames:

and the truck tarp:

and the best: It is sealed now!

Pedelec Controller Post 3

It was a little bit more to do than expected.

  • rearranged the connectors, the fet and the Voltage regulator
  • added one small FET for Lights
  • added a fast DUAL Mosfet driver IC
  • added an LM317 for the Mosfet driver IC
  • build the thing into a box
  • added a shunt for output current measurement
  • added a voltage divisor to get the current battery voltage

After a few hours of sleep, I will blow that up, again!

State of the bike

Today as expected I blew up the controller!

Nature can not be fooled!

  • A MosFET with 30 Vds on a 40 V power source will die immediately!
  • A MosFET with 100 Vds on a 40V power source after 10 meters

I am still not exactly sure why the last law is taking action, remember, these are still my first elektronics experiments. I think it is either that I connected the FET without a driver, or it is because the starting current of the Motor is too high!

Maybe it is both, so I will go to the Metalab, making a few Modifications this Night.

Pedelec Controller Post 2

The controller is complete now!

– 16 MHz Quarz
– RS232 with Max232
– padelec sensor on PC1
– throttle on PC0
– status LED on PD7
– MosFET on PD6/OC0A

Source code is available here

I will try to blow that up tomorrow! 😉

Pedelec Controllers Progress

The start in the morning was great! I discovered that the RS232 on my padelec controller was not working because I set the wrong registers to enable it.

When I continued developing I discovered that the hall sensor for the pedals is getting a resistance of nearly 0 ohm on its power supply when I bring it into a magnetic field.

Because it is packaged I can’t take a look inside which sensor they used so I have to guess. I guess that using only the red and the blue wire for signalling, leaving the black wire out, is wrong, but seems to work, so I decide not to think to much about it.

The Pedelec Controller Post 1

Here are the first pictures of the developing of the pedelec controller:

Lessons learned: I will never do an in circuit RS232 level conversation in one of my projects again! Building one external adapter is better.

Here is a first hopefully working version of the controller:


  • RS232 Debug Output
  • PWR throttle
  • Connection for Gas switch
  • Connection for Pedal hal sensor
Pedelec Battery Pack

The batterypack that coming with my pedelec consist in 26 NiCD Cells with 7200 Ah. The first thing I did was putting all the cells apart, and charging them seperately.

Then I build 6.5 packs contaning 4 Batterys with japan plugs for each cell:

I also started building a Charger unit with two LM317 as constant current, and an Atmega Tiny for delta U switch off. I still don’t know how good that old cells will work.

As you can see, I make instant developing, the circuit develops itself instantly on the board. Also, I did not gave much love to it because I still don’t know if the batterys are working.

The Pedelec Project

A friend donated me a pedelec which was lying in his garden for two years now. Actually it where two half padelecs, a front half and a back half, broken right behind the steering head, without a controller, and with an old battery pack.

The first thing I did was welding the two pieces together an weld in a top tube to make the frame stronger:

Understanding the Energy Problem.

I wrote this originally in 2009-05-25 so this is the article copy’n’pasted:

Today I tried to learn a little bit about our energy problem.


On my sunday evening ride back home from SigINT in cologne I took the Country Road B9 from Cologne to Neuss. When you drive near Neuss the first thing you will see is a huge elektrical transforming areal.

The next big place is ALU Norf an aluminiun factory. To produce aluminium you need a lot of elektricity because the whole separation process depends on elektrical power.

The elektricity is delivered to the factory from three lignite (brown coal) power plants 10 miles in the east.


How much windmill do you need to power an aluminium factory from?


According to a presentation I found at Google, Alu Norf is needs
about 3,4 TWh p.a. I hope p.a. means something like per Year.

3,4 TWh = 3400000 MWh

I expected a maximum output of 4 mw per windmill, according to wikipedia one windmill inside the country delivers maximum output for 2000 hours per year.

That is everything I need.

3400000 MWh / (2000 h * 4 MW) = 425 Windmills 

This is a Minimal number of windmills, in reality it will be much more, about 1000.

Posted on July 15, 2010, 6:02 am By
Comments Categories: misc

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