169: Thursday 28th October 2010

I had a chat with some of the guys at work about the throttle pot and I am going to see if I can track down a hall effect throttle positions sensor. I know I can get an automotive potentiometer and this will do to get started. Hopefully we can find something tomorrow or I will have to buy another unproven pot. The one I fitted yesterday is still o.k. at the moment. I am starting a guide to converting a car to electric on another blog. I shall put the address in the next posting. If you have any burning question, I will answer them in that blog. I shall keep this blog for the Probatron and the different experiences I have with him.

and here it is:

168: Wednesday 27th October 2010

Another one bites the dust. I broke down again today, I lost throttle control completely. The controller programmer box was indicating the accelerator voltage fault. Double disaster, my mobile phone battery had gone flat and I put it on charge through my USB port at work, and left it there. So here I was half way up a busy hill, hazard lights on, no drive and no phone. As all the angry drivers overtook me, I gradually backed up to a side turning and with a bit of a run up (backwards) I managed to go round the corner and get parked rather well in one move. I think it was more luck than judgement. I locked up the Probatron and went off to the nearby shops to find a payphone. Fortunately my wife had just come in and answered the phone. I got her to bring some 10mm spanners so I could remove the throttle and take it home for repair. She stayed with sparky while I went home and changed the pot. About an hour after the first phone call I was back on the road again on the way home. I am having a run of bad luck with potentiometers. However, I have found that the original pot that was too high for my controller at 20k ohms had a 10k resistor in parallel to bring it down to below 10k. Closer examination found that when this started playing up it was only the 10k resistor on the pot that kept it going, other wise it would have failed just like this one. This leads me to a quick repair that I can do so I don't get stranded in future. I shall keep a 10k resistor in the car and if my throttle fails again, then can links this across the input so the voltage can be detected even if it is wrong, it may be jerky, but it will get me home and the throttle switch safety override will prevent any run away as drive is removed when I lift off the pedal (and hence the micro switch). It's not perfect, but until I find a better throttle potentiometer it will get me home. I did find one on eBay that looks exactly like the original, but I can get it as a 10k linear pot, cool.

167: Monday 25th October 2010

I travelled one mile this morning and turned back home. My temporary throttle had given up and I could only muster 20 mph. I came back home told my beloved that I was going to take her car to work, she told me otherwise, then a few minutes later after a short discussion I was out in the garage very hurriedly fixing my car with another temporary potentiometer. It actually only took me about 20 minutes to fix it. I got to work o.k. and home again, but it was being a bit tetchy on the way home too. Fortunately my new throttle potentiometers came in the post today. In the photo below you can see 3 pots. Sorry about the picture quality as my digital camera had run out of batteries. I put some new ones in and they died straight away. I need to get some better batteries, so I had to use my phone instead. Anyway, the big pot is the original that came with the metal box and lever, the little one is what I have used for a temporary fix, and the orange / red one is the new one. The temporary pot has a 4mm plastic shaft. The new pot has the right size shaft and it is metal. I rewired my state of charge gauge too, so now it represents the voltage levels at all times, but I wired it to the wrong side of my throttle switch, so the gauge only reads when I press the throttle. It will be a quick fix tomorrow. The throttle response is superb now. Previously I had to press the throttle pedal about half way before I got forward drive. It did not seem to matter how I calibrated it. I can only assume the pot track was laid like that. As this new pot is wire wound, it accelerates as soon as I touch the throttle and feels just like the throttle pedal on a petrol car. It is smooth and really nice to drive. I don't feel like I have to drive it special now. I am really pleased with this.

166: Saturday 23rd October 2010

It has happened again, but this time I can detect the symptoms. The throttle pot is starting to go again, so I have limited my car use over the weekend as I have some new pots on order. 10k 1W wire wound linear pot x 2 should hopefully do the job and I have a spare in case they are not quite up to the job. There are higher wattage types also, but I believe the ones I have fitted now cannot tolerate being outdoors and being a carbon track type, it would not behave well with moisture. The wire wound type is sealed and much more tolerant of moisture. Hopefully this will be something I can put to bed for some time. The new pots should arrive Monday and will probably take about an hour to fit.

165: Sunday 17th October 2010

Today I was dropping off a friend of my daughter, then I lost control of the throttle. I was getting no drive until I nailed the throttle pedal, then I got full throttle. It was like having a throttle switch with full on and full off as the only states. I put him in 3rd gear to smooth the drive out a bit and got home. I checked the throttle using the tester function on the controller with the gearbox in neutral and I could see no change until about 80% when the motor fired up. So the throttle potentiometer was playing up. This a heavy duty sealed type potentiometer, so there was nothing I could do but change it. I had some 10k pots in my electronics spares, but the shaft was 4mm compared to 8mm of the original, so I used some brass tubing to increase the shaft size. I fitted the lever back and put it all on the car, then I had the controller learn the new throttle pot extremes. When I tried it again, control was back to normal so I had nice control across the range of the pedal. Thankfully this happened in the early afternoon, so I had a good amount of time to solve the problem. So it all seems o.k. now and I have a bag full of these potentiometers in my garage in case it goes again. I think this was my first breakdown where something has actually gone wrong and needed repair other than just charging up. I am not counting my original batteries as they were second hand to start with and only a temporary solution. When they did give in, it was nothing less than expected and planned for.

164: Saturday 16th October 2010

I knew it was a mistake to say that Sparky was behaving himself. The Probatron was all charged ready for its first trip to football training. We set out with 18 miles done, arrived at the normal time at football training with 125v still reading on the tester, all was well. 2 hours later we set off to come home and once we were on the main road it seemed to be constantly uphill all the way home. I was watching the battery voltage going down and down until when we was about 6 miles from home the controller started cutting out. I limped it into a lay by and just let the voltage build up again. when we were back at 120v I set off again, but I knew it wouldn't last long. We got within 2 miles of home and it was cutting out again. I knew we had a hill to go up, so we stopped for another 5 minutes or so to let the voltage recover again, and we managed to limp home. After about 4 hours of charging a quick local trip out and all was back to normal. It is clear now that the Probatron cannot maintain a long period of higher current. I could probably try again using up to 3rd gear only so as to keep the current lower and drive at a slower speed, say 50 mph. I also believe that having my daughter and my wife probably added over 100kg of weight and this affected the range. So for now I shall set a 30 mile limit for our journeys when we are all in the car as we got to 31 miles when it cut out first time today. I just hope this hasn't affected the life of the batteries too much. I can't believe my test runs gave me 40 miles with maybe a couple more to spare. However this was done in several shorter journeys. I learnt something today. It is good to know the Probatron is back to normal just for a charge though.

163: Friday 15th October 2010

Nothing much happening with the Probatron recently. It has been behaving itself.
There has been, and will continue to be an accelerated amount of news surrounding the introduction of the various large brand offerings of electric cars.
The Chevy Volt has taken a beating in the press for keeping some of the details about the drive system quiet while they get their patents sorted out. Nissan are soaking up all the press they can get for their battery only electric vehicle the Leaf. Mitsubishi with the iMiev battery car, Peugeot's ion (iMiev with different calibrations and paint job), the Renault Fluence and the relationship with Better Place for battery swapping stations etc.
I am confident we will start seeing lots of pretentious adverts on TV soon, if they haven't already started. I have seen some on-line. My wife loves the Nissan Leaf polar bear advert, but was only interested in how cuddly the bear was, no interest in the car at all.
There has been much talk about how China wants to control the technology that is allowed to be sold there.
As you may know I work for Ford, and initially they had others build retro-fit prototypes in the form of Smiths for the Transit Connect and Magna for the Ford Focus and then taken them on to develop it further in the Ford factories. The Transit connect now being kitted out by Azure Dynamics and the Focus still by Magna. Fairly well proven systems in both cases and Ford are not making so much noise about the electrification as some of the other brands and in my opinion appear to be offering the customer electric options if they want them rather than thrusting a position or standpoint on the public. There has been some publicity, but not too much boasting.
Then to continue my rant, there is all the hoo-har about charging points. I know that in the U.K. I could plug in just about anywhere there is a 240v 3 pin plug. It seems that every utility company has a fancy looking post with a socket on it that costs thousands of $s or £s. It cost me less than £20 to set up a 240v 16A socket alongside my garage door. I find it frustrating that the authorities can't just find a local electrician to put in 10 ordinary electric points that are suitable for car charging in every large car park and pay the car wash guy to paint them spaces green with some floor paint and write "Electric Car Parking" alongside all for about £2000. That would be about 2 days work for me on my own and would make me fairly well-off if I could get a couple of gigs each week. Apart from everything else it could all be done in just a few months and cost just a few millions for the whole country. It seems that we are seeing this sort of money being spent just on consultations with not a damn thing being installed anywhere. Then when some fancy posts do appear one or two at-a-time in some obscure places and then cost 10s of thousands of pounds or dollars.
I read regularly about people arguing that coal fired power stations producing CO2 when generating electric that would be used to charge cars. No matter who does the calculating, this still pollutes less than the millions of petrol cars on the road, but the figures now show that truly electric cars are not completely clean. I watched a program on TV that had the American government in for about 1.5 trillion dollars worth of coal fired power stations before 2050 with a life expectancy of about 50 years, but using sequestration to clean the emissions into porous rock beds. I am not totally convinced that this egg basket is the right place to put all your solutions either. So another idea to come out was closed nuclear power stations where the waste is re-used over and over. Wind power and solar power don't have enough coverage for the outlay to provide for all.
For all the things that are starting now, the next 5 years are going to be really interesting. I would be surprised if there was another war somehow related to the introduction of electric cars and at least one major environmental disaster. I am sure that in 2015 we will still be trying to understand what is the winning solution set, whether this is right or wrong, and by 2020 we will be wondering what all the fuss was about.
I will be really interested to get some comments going on these subjects since I have only got my amp gauge and matrix display to build now for the Probatron. Plus adding Lambo door hinges and a blingy paint job.