Saturday 9 July 2011
Friday 8 July 2011
Wednesday 6 July 2011
Monday 4 July 2011
Sunday 3 July 2011
Friday 24 June 2011
Thursday 23 June 2011
And enter discourse
But can’t agree
On a Trojan Horse
While greedy capitalists
Flock like birds
And war with bombs
Instead of words
But do we know
The worlds for lease
And the contract expires
In hand with peace.
By Graham Boyles.
Wednesday 22 June 2011
Tuesday 21 June 2011
I arranged a visit the bike and determine the fault.After much thought trying to figure out how to remove the covers and expose the battery pack, we finally opened the enclosure with 102 cells arrange in two blocks. The rear block is 9 cells long, 2 wide and 3 cells deep. The front block is 8 long, 2 wide and 3 cells deep. Each set of 8 / 9 is bound by a steel compression band to prevent the cells from expanding when heated during charging and discharging. Each layer comprises of two rows of 8 / 9 in a plastic frame. Each of the 3 layers is held together by long threaded rods extending between the rows and also by duct tape around the outside of the plastic frames.
The top of the rear block was removed and some evidence of heating and corrosion was visible on one of the cells.
Leaky cell and voltage - temperature sensors
The cell had overheated, the plastic frame the cell sits in was melted, and the pressure relief valve on the top of the cell had released causing some corrosion and crystallisation of electrolyte around the top of the cell. We verified the cell had failed electrically also. It measured only 32mV.
The temperature and voltage sense boards were also disconnected at the connectors at the front and rear of the bike.
There are temperature and voltage sensing elements screwed to some of the battery terminals. These were numbered with a marker on each sense board and also on the cells they were removed from to ensure they were replaced in the correct locations. Each sense board was wrapped in insulation tape to prevent them accidently touching the battery terminals once removed.All the other cells were of the correct voltage (~1.3V) and had no physical signs of failure. Disassembling the blocks was fiddley. The cells are assembled in plastic frames that are then joined with steel compression bands to prevent cell swelling.
I have made a jig for compressing the packs in order to remove and replace the steel bands more easily. To make things more tricky, the brittle locating tabs
I proceed to replace the 3 cells in a string of 9. Each ½ layer of cells is bound in steel a binding strap to prevent the cells swelling during charging and discharging. I have made a jig for compressing the packs in order to remove and replace the steel bands more easily.
An interesting point is that each cell is electrically insulated from the next by plastic spacers.
Reassembling the pack consisted of reversing the disassembly process. Extra care was taken to double check visually and with a volt meter that each 9 / 8 cell bank was reassembled correctly and the temperature and battery voltage monitoring sensors were installed in the correct locations.
All interconnects and battery terminals that had been removed were tightened to a specified to torque of 10Nm.
After reassembly the owner took the bike for a ride and came back with a memorable grin. The bike performed better than it had for a long time.
The final task for the owner is to deep discharge the pack 5 times to condition the batteries and ensure longevity of the new batteries. This procedure is recommended by Vectrix to remove any ‘memory’ effect in the batteries in order that they can provide the maximum usable capacity.
Friday 20 May 2011
Monday 2 May 2011
Wednesday 6 April 2011
Here it is leaving my place for the last time.
It is destined to have new life breathed into it with a new VFD and some 30Ah Vectrix electric motorcycle batteries.
My 'new' BMW E30 318i may become my new project :)
Monday 14 March 2011
Well I finally bought an E30 BMW 318i Coupe, with a manual gearbox.
Great fun to drive. It is a bit bogan, so like the ute, I will remove the tinting and put a chrome grill insert back into it.
If it does become an EV, then it will most certainly need to have some respectable times at the drags!
Here are some pictures to get started.
Saturday 26 February 2011
Wednesday 23 February 2011
I was excited when the 555 contest was announced to recognize the most used Integrated Circuit ever.
After considering for a while what I could do for the competition, I started thinking about how best to celebrate the 40 years that the device has been around and the 10s of billions produced.
I have often admired home built computers that use discrete components so I though, I will make a 555!
This 555 project recreates an operational 555 timer using discrete transistors, resistors, diodes and capacitors.
It may not strictly conform to the competition rules, but I thought it would be fun and original anyway.
I downloaded a few 555 datasheets from various manufactures only to find that the circuits often have subtle differences. Eventually after some Googling I located a scanned copy of the original Signetics datasheet from dapj Circuits, Including the Equivalent Circuit below.
After inspecting the circuit, I noticed Q19 is rather unusual and has 2 collectors. How can I implement this using discrete components? I decided to simulate the circuit using the brilliant and free Java app from falstad.com to make sure it worked and to quickly experiment with different arrangements for Q19.
Arranging the resistor on the base of Q19 as in the simulation works perfectly. If I used 2 transistors to replicate the original Q19 design, the circuit did not oscillate.
In order to simply construct the circuit to show its operation and at the same time preserve the original authenticity, I photocopied and enlarged the Philips schematic, glued it to some card and inserted the components through the card and used point to point wiring on the rear of the card.
Rear of card using soldered point to point wiring. Drawing pins are used to secure the input and output pins. Much ice cream was consumed during the construction of this project.
A pin was used to poke holes in the card to insert the components. This was a surprisingly quick method of building the circuit. For prototypes of simple circuits I may use this technique again.
the only thing I might do differently is to paste a reverse image of the circuit onto the wiring side of the card in order to avoid wiring errors.
In order to test it works, I attached an LED to the output and suitable timing components, Ra, Rb and C to give an approximate 1Hz flash rate.
the final testing can be seen in the this video.
The final thing to do is to make the project presentable. I decided the inside of an old data book would be appropriate. I found a copy of a suitable book on the 'free' table of my local ham radio club, the Manly Warringah Radio Society.
This was the first time I have used a book as an enclosure. It works well if you are not in a hurry, which I wasn't. I followed the guide by Bre Pettis from Make Magazine. (Cool guy who I had the pleasure of meeting at a Maker Faire in Austin, Tx.)
One half of the book was cut to accommodate the circuit, while the other half was to house a battery, the 555 timer data sheet and memorabilia.
The left hand side of the book contains A5 printed copies of the Philips data sheet, The 555 Timer Wikipedia page and finally an interview with the 555 inventor Hans R. Camenzind.
The finished project closes nicely into the book for safe keeping.
Saturday 19 February 2011
Friday 11 February 2011
The report, a leading statement of the planet's health, found that people are spending beyond the Earth's ecological means and dipping far into the Earth's natural capital. The ecological deficit caused by consumption of energy, water and materials at rates 50 per cent beyond supply will have serious repercussions for wildlife and ecosystems, as well as for future generations of people, all of whom depend on nature's ecological services.
Australia is #8 and New Zealand has the 32nd most heaviest footprint.
Monday 7 February 2011
Monday 17 January 2011
ELECTRIC TRUCKS GAIN TRACTION--Carl Schwab - IEEE Consultants' Network of Long Island