electric/petrol hybrid revisited

[coln72]

G'day all,
Some may remember last year my team and I tried to build a petrol/electric hybrid trike for a 24hr race against other schools, and that we ran into a lot of issues with speed controllers self destructing. On lasted 20 metres Eventually the decision was made to ditch the electric side and fit up pedals to make a pedal/petrol hybrid to get us into the race.

That was last year. Things seem to be progressing well this year with producing a reliable electric system (touch wood) and I have taken the trike out for a spin with no electrical issues for the first time

Our current set up is a 450w brushed motor (I know its not the most efficient) running on 24 volts. The reason I chose this motor is because it has a 5:1 gear reduction, allowing the use of the 10 speed rear cluster and derailure set up I already had with my 20" rear wheel. Theoretically I should see a speed range of 30 to 70km/h or so at max motor revs. On the first test it was comfortable sitting around the 30km/h mark with a burst up to 40 km/h. As it was its first real run after frying the last motor (200w/24V) I was taking it real gentle. I hate the smell of burning electrics :?

The controller chosen is a Jaycar kit, number KC 5465. It is rated for 40 amps continuous and up to 60 amp bursts. This seems fine as by the event regulations I have to run a 30 amp max fuse - which I blew yesterday taking off too hard in the wrong gear

Spent today playing with the electric throttle, building in a return spring to ensure that it shuts off when not being used. Without this, stopping was fun....

Well thats enough for now, will post some pics up when I get them downloaded.

 

[jmygann]

http://trihybridstealth.com/WordPress/2010/06/20/the-future-of-cars-myhighplains-com/

 

[coln72]

200 mpg is not bad but last year we travelled 442km before the event got cancelled on around two litres of fuel - out of the three allocated for the 24 hours. If my maths is correct then that is around 500 mpg

I should of mentioned that for the event we are not able to charge our batteries using mains power and that we only get 3 litres of fuel to cover the 24 hours. It is up to us how we use it whether it is in a generator to charge that batteries or in a motor to drive the trike in addition to the electric motor.

 

[coln72]

As promised a couple of pics. The standard f finish is nothing like some of the others on this site, like Aussie Jester or Recumbrance, but it not to bad for being mostly done by school kids.

View attachment 4





As I said, some of the work is a bit rough and ready at the moment as everything is evolving as we go on. For example, the throttle for the petrol motor has been changed since the pics were taken on Thursday to something a bit more user friendly.........
The final build will be a lot sexier

 

[12p3phPMDC]

what a great program coln72!

THose kinds of events are priceless not just for your education, but for your life experience...

Good luck on the hybrid!

 

[coln72]

GRRRRRR - stupid bloody short

Stuffed around hooking up a digital panel meter so we could get a read on battery usage today and mounted one on the trike. As one of my students was giving me a hand after school, I decided to let him have a try of the electric motor and to test some of the other mods done over the last few weeks. Started OK but the terminals of the pot got bumped - the pot is mounted on the steering lever - shorting to of the wires. Motor went straight to full throttle blowing the fuse. OK replaced the fuse. Pop, straight away. Do it again, same result.

Look over wiring, as with the pot on zero, the motor should not of been trying to turn. This is when I noticed the pot terminals touching Ok, back to the workshop where I found that I was out of fuses Mmmmm, fixed pot, wired it up without the fuse thinking problem was fixed. You guessed it. Hooked up the batteries and trike tries to move, WITH THE THROTTLE ON ZERO, then poof. Lotsa smoke from the speed controller. Looked inside and lotsa fried components. Lucky I have a couple of spares of these.

Thinking, that the shorting of the pot must of killed something in the controller, causing it to to give 100% no matter what the pot was set to. Did this a while ago when we shorted the circuit board in the controller while testing.

At least the petrol motor is running and moving the trike