Gas powered electric- a measure of sucess

[AussieSteve]

I think regardless of if the motor is directly powering or 'indirectly' powering the bicycle the 200watt law would somehow raise its ugly head in OZ...at the end of the day the motor is required for powered motion, if its over 200watt the would have a problem i think
KiM

You got it right. In the case of a hybrid, here in NSW Australia at least:-

A power-assisted pedal cycle is a cycle that:
- Is designed to be propelled primarily by human power; and
- Has one or more auxiliary propulsion motors attached that have a combined output of no more than 200 watts.

I've attached a pdf document that says it all.

... Steve

 

[professor]

This doesn't pertain to the Australia issue, but if one chooses to use a 110v generator, the bike could also use a 110v drive motor for propulsion, like from an electric snowblower or leaf blower or treadmill?
Completely bypassing the need for a battery. could use a small floodlight for a headlight too. It's still an e-bike to me. Again the weight of the generator is problem but maybe it could be mounted in the frame.

 

[AussieSteve]

This doesn't pertain to the Australia issue

Doesn't need to pertain to the Australian issue - this is your thread.
Sorry for getting off-topic.

but if one chooses to use a 110v generator, the bike could also use a 110v drive motor for propulsion, like from an electric snowblower or leaf blower or treadmill?
Completely bypassing the need for a battery. could use a small floodlight for a headlight too. It's still an e-bike to me. Again the weight of the generator is problem but maybe it could be mounted in the frame.

Do you mean a 110V generator set up so that the output voltage to the electric motor varies as RPM varies, or a fixed 110V generator output with a speed controller of some sort to vary voltage?

A variac would work as a speed controller. It would take 110V input and allow smooth variation from about 5-10VAC to 110VAC or more. I have one here rated at 500W, (240VAC). It goes from about 10VAC to 260VAC ouput from a 240VAC input - a slight step-up for more boost.It could even be fitted with a cable, with a little ingenuity.
A variac is pretty heavy, though. About 10 lbs for a 500W version is my guess.
Pics attached. (See thumbs below.)

*Be careful with this idea - you could easily fry at 110V with that much current available. Beware in the rain! Ensure that everything is well-earthed and insulated (and wear a rubber suit, just in case. A wetsuit with hood and booties might do nicely.) Only kidding - good luck with your project. If I can help in some way...

... Steve

 

[ibdennyak]

You got it right. In the case of a hybrid, here in NSW Australia at least:-

A power-assisted pedal cycle is a cycle that:
- Is designed to be propelled primarily by human power; and
- Has one or more auxiliary propulsion motors attached that have a combined output of no more than 200 watts.

I've attached a pdf document that says it all.

... Steve

Guess I am disappointed that your regulations are so restrictive, but at least it is laid out in terms that a layman can understand. Any law in the US would have more whereas'es and whyfor's than your entire law. For some reason I pictured Australia as being a little more understanding. Hmmm, Next they will be telling me there is no Santa Claus.

 

[loquin]

I would avoid the use of a 120 VAC motor, if for no other reason than that, with a battery intermediate stage, if asked by law enforcement "why you have a motor running," you can truthfully say that it's "just to keep the batteries charged, officer." and be able to ride away only on battery power, demonstrating that it is truly an e-bike.

 

[ibdennyak]

I would avoid the use of a 120 VAC motor, if for no other reason than that, with a battery intermediate stage, if asked by law enforcement "why you have a motor running," you can truthfully say that it's "just to keep the batteries charged, officer." and be able to ride away only on battery power, demonstrating that it is truly an e-bike.

That's a good point. That was my original theory too. Never had to bring it up though. Guess I was lucky. I used to kill the engine and ride through a park/playground area on electric. It was a non motorized area, but I was never questioned there either. Course it helped to keep the speed down, and make a point of giving the joggers and bikers their space.

 

[AussieSteve]

I agree with you guys. A battery system is the ideal way to go, with an 'auxilliary' charger/generator. Ideally, 10Ah-20Ah LiFePo4 (Lithium) battery, brushless 400/450W motor, alternator w/ rectifier & regulator and a tiny IC engine to run the alternator. A 500W engine w/ alternator could charge the battery from flat pretty quickly and top-ups in no time.
Regenerative charging on the electric motor. Especially if connected to brake controls so stored kinetic energy goes back into the battery rather than burning off as heat. Charge up with petrol/gas when the roads are open or battery is low, but run on electric the rest of the time. Still, here, that would be illegal. Our laws are a PITA. Unless total power of generator AND electric motor don't exceed 200W. Useless.
My electric bike is 200W, (legal here) and doesn't have much pull. Lucky I only weigh 50kg. (110 lbs) I get 30kph (18mph) max, average 22 (13mph), for 32km (20 miles) on a 200W 36V brushless hub motor with a 36V 10Ah LiFePo4 battery... Still better than pedalling.

However, it's a hobby project for Professor, not necessarily an attempt at high-tech or new innovations. I'd like to see what he comes up with...

... Steve

 

[Flapdoodle]

Been kicking around the idea of using an electric trolling motor to power a bike.

I considered this too, but abandoned the idea when I realized two things:

1. The bearing nearest the prop is meant for thrust loads and might not last with a sprocket and chain putting a side load on it.

2. The electronics in my Minkota are encapsulated in the nose of the motor and meant to be water cooled.

I would eventually like regenerative braking, but I am wondering just how much practical power could be recovered. After all, it is still a bike. Does anyone have some real figures?

 

[AussieSteve]

I would eventually like regenerative braking, but I am wondering just how much practical power could be recovered. After all, it is still a bike. Does anyone have some real figures?

As I mentioned earlier, I played with DC motor regeneration a couple of years ago, but never measured actual charge currents from the motor, except that I remember that a 100mA DMM range was reading high from trying to spin the motor with my fingers - 12V 200W motor, 7Ah lead-acid battery.
I read once that you can expect to recover up to 25% of the power that would go into accelerating the motor for an equivalent deceleration.
ie A 12V motor as a generator could produce 4V under load at similar revs. Don't have any idea how accurate this is.
The basic theory is that the polarity of the voltage applied to the motor is reversed very rapidly, 10,000-100,000 times per second, (Hz).
The pulse width is varied to determine direction and speed. If the pulses are equal, the motor stands still. If the forward pulses are wider, the vehicle moves forward. If the negative pulses are wider, the vehicle moves backwards. Diodes in the circuit ensure that if the voltage from the motor is higher than battery voltage, the battery is charged. I hope this makes sense to someone.
... Steve

 

[AussieJester]

Lucky I only weigh 50kg. (110 lbs)

No wonder you can get away with it **** my arms alone weigh 50 kilo hahaa...light weight

KiM